HELP Short? Wiring gremlins need wiring guru Ungo box may be an issue?
12-29-2010, 05:42 PM
#1
Rennlist Member
Thread Starter
HELP Short? Wiring gremlins need wiring guru Ungo box may be an issue?
Things are not looking too good over here
This issue is like an octopus as it has so many facets ... Where to begin?
As some of you may know I have been working on this car for a pretty long time
The list of items yanked are far and wide .. here is a short list ( no pun intended )
Battery, Alternator, Starter, the whole front end bumper including all headlights fog lights horns etc Everything on the engine except the engine grounds and ref sensors
I pull the head unit and found the worst wiring job this side of the Mississippi....
I disconnected most or the stereo stuff but have a harness that is still connected to the back of the slide out surround of the head unit ... I was planning on getting the interior wiring ready for the install of the SMT6 Zeitronix wide band, boost controller gauges and re-wire the stereo. So I was looking to identify, wires that I had in the stereo harness that once was, but is no more ! Using a Volt/Ohm meter I went about testing the wires ... I am getting all kinds of crazy-*** reading. Grounds and hots to the chassis are showing up as the same ??
I even went to the battery terminals and put the continuity tester across both the positive & neg cables and got a full continuity reading .... That can't be normal, can it ?
Let me state for the record, I am no wiring genius! I know just the basics
I need help, big time here, as I can't really feel confident in wiring anything, when there could be a short somewhere?
I think that the alarm may have something to do with this, but I really don't know? ... This car has been idle for over 5 yrs .... I do remember, years back, that when the battery was low, the alarm would go off ... and when you disconnected the battery... when you then reconnected it again, it would set the alarm off and you would have to use the remote to get it cleared maybe that is what is causing the short I HAVE NO IDEA ...?
All I know is I am in the ****ter right now and need some solid advice
I mades sure that all the wires I had left disconnected are not touching each other i.e. starter alternator etc
Any help would be greatly appreciated
Thanks in advance
Ed
This issue is like an octopus as it has so many facets ... Where to begin?
As some of you may know I have been working on this car for a pretty long time
The list of items yanked are far and wide .. here is a short list ( no pun intended )
Battery, Alternator, Starter, the whole front end bumper including all headlights fog lights horns etc Everything on the engine except the engine grounds and ref sensors
I pull the head unit and found the worst wiring job this side of the Mississippi....
I disconnected most or the stereo stuff but have a harness that is still connected to the back of the slide out surround of the head unit ... I was planning on getting the interior wiring ready for the install of the SMT6 Zeitronix wide band, boost controller gauges and re-wire the stereo. So I was looking to identify, wires that I had in the stereo harness that once was, but is no more ! Using a Volt/Ohm meter I went about testing the wires ... I am getting all kinds of crazy-*** reading. Grounds and hots to the chassis are showing up as the same ??
I even went to the battery terminals and put the continuity tester across both the positive & neg cables and got a full continuity reading .... That can't be normal, can it ?
Let me state for the record, I am no wiring genius! I know just the basics
I need help, big time here, as I can't really feel confident in wiring anything, when there could be a short somewhere?
I think that the alarm may have something to do with this, but I really don't know? ... This car has been idle for over 5 yrs .... I do remember, years back, that when the battery was low, the alarm would go off ... and when you disconnected the battery... when you then reconnected it again, it would set the alarm off and you would have to use the remote to get it cleared maybe that is what is causing the short I HAVE NO IDEA ...?
All I know is I am in the ****ter right now and need some solid advice
I mades sure that all the wires I had left disconnected are not touching each other i.e. starter alternator etc
Any help would be greatly appreciated
Thanks in advance
Ed
12-29-2010, 06:59 PM
#2
Rennlist Member
Thread Starter
Oh another part that was removed was the entire center console with all the switches etc
Just to be clear on that babble above what I was trying to say is
When I connect the continuity meter to the two battery cables ( there is no battery in the car )
I get a full reading on the meter, the same as if I connected the meters leads, to each other????
WHY ??? That can't be correct can it ?
Just to be clear on that babble above what I was trying to say is
When I connect the continuity meter to the two battery cables ( there is no battery in the car )
I get a full reading on the meter, the same as if I connected the meters leads, to each other????
WHY ??? That can't be correct can it ?
Last edited by Crazy Eddie; 12-29-2010 at 07:26 PM.
12-29-2010, 07:31 PM
#3
Nordschleife Master
Ahhh, welcome to the world of the Porsche electrical system... well pretty much any german car, but our are particullarly interesting..
Whats the end goal?
Do you have a set of the wiring manuals, not the PDFs but the actual factory manuals? If not let me know, I have 2 sets..
You said you want to rewire the stereo.. not a bad idea, but takes some interesting turns dealing with the powered antena amp for one..
the power and ground both reading to chassis isn't suprising.. lots of variables there..
1) If you suspect a short.. with the meter connected to the battery cables, goto the fuse panel and one at a time remove each fuse and relay, if the short goes away you found the bad circuit
2) using the electrical schematics you can trace the wires for that circuit until you find the short IF it is in the wiring, if the wiring is all good it is either the relay or component in that circuit (any switches turned on?)
3) electrical diagnosis and repair can be a royal pain in the *** for someone experienced with it, and a total nightmare for someone NOT familliar with it.. if unsure, I would recommend getting someone experienced with the car, and the cars electrical system to check it out..
Sucks, good luck, and feel free to email me if you have any other issues!
BTW, How is Los Altos this time of year? I am feeling a vacation coming.... need some space from things, and time to clear my head.. and I love playing with the electrical systems on these cars...
OH, and is it possible the starter wires are resting on the chassis or the bellhousing, or the alternator is shorted? disconnect the wires from teh alternator to issolate it.. check for a HOT wire touching the chassis of the car!
As for the harness still connected to the stereo.. is it the antena wire?
Whats the end goal?
Do you have a set of the wiring manuals, not the PDFs but the actual factory manuals? If not let me know, I have 2 sets..
You said you want to rewire the stereo.. not a bad idea, but takes some interesting turns dealing with the powered antena amp for one..
the power and ground both reading to chassis isn't suprising.. lots of variables there..
1) If you suspect a short.. with the meter connected to the battery cables, goto the fuse panel and one at a time remove each fuse and relay, if the short goes away you found the bad circuit
2) using the electrical schematics you can trace the wires for that circuit until you find the short IF it is in the wiring, if the wiring is all good it is either the relay or component in that circuit (any switches turned on?)
3) electrical diagnosis and repair can be a royal pain in the *** for someone experienced with it, and a total nightmare for someone NOT familliar with it.. if unsure, I would recommend getting someone experienced with the car, and the cars electrical system to check it out..
Sucks, good luck, and feel free to email me if you have any other issues!
BTW, How is Los Altos this time of year? I am feeling a vacation coming.... need some space from things, and time to clear my head.. and I love playing with the electrical systems on these cars...
OH, and is it possible the starter wires are resting on the chassis or the bellhousing, or the alternator is shorted? disconnect the wires from teh alternator to issolate it.. check for a HOT wire touching the chassis of the car!
As for the harness still connected to the stereo.. is it the antena wire?
12-29-2010, 08:21 PM
#4
Rennlist Member
Thread Starter
Ahhh, welcome to the world of the Porsche electrical system... well pretty much any german car, but our are particullarly interesting..
Whats the end goal?
Do you have a set of the wiring manuals, not the PDFs but the actual factory manuals? If not let me know, I have 2 sets..
You said you want to rewire the stereo.. not a bad idea, but takes some interesting turns dealing with the powered antena amp for one..
the power and ground both reading to chassis isn't suprising.. lots of variables there..
1) If you suspect a short.. with the meter connected to the battery cables, goto the fuse panel and one at a time remove each fuse and relay, if the short goes away you found the bad circuit
2) using the electrical schematics you can trace the wires for that circuit until you find the short IF it is in the wiring, if the wiring is all good it is either the relay or component in that circuit (any switches turned on?)
3) electrical diagnosis and repair can be a royal pain in the *** for someone experienced with it, and a total nightmare for someone NOT familliar with it.. if unsure, I would recommend getting someone experienced with the car, and the cars electrical system to check it out..
Sucks, good luck, and feel free to email me if you have any other issues!
BTW, How is Los Altos this time of year? I am feeling a vacation coming.... need some space from things, and time to clear my head.. and I love playing with the electrical systems on these cars...
OH, and is it possible the starter wires are resting on the chassis or the bellhousing, or the alternator is shorted? disconnect the wires from teh alternator to issolate it.. check for a HOT wire touching the chassis of the car!
As for the harness still connected to the stereo.. is it the antena wire?
Whats the end goal?
Do you have a set of the wiring manuals, not the PDFs but the actual factory manuals? If not let me know, I have 2 sets..
You said you want to rewire the stereo.. not a bad idea, but takes some interesting turns dealing with the powered antena amp for one..
the power and ground both reading to chassis isn't suprising.. lots of variables there..
1) If you suspect a short.. with the meter connected to the battery cables, goto the fuse panel and one at a time remove each fuse and relay, if the short goes away you found the bad circuit
2) using the electrical schematics you can trace the wires for that circuit until you find the short IF it is in the wiring, if the wiring is all good it is either the relay or component in that circuit (any switches turned on?)
3) electrical diagnosis and repair can be a royal pain in the *** for someone experienced with it, and a total nightmare for someone NOT familliar with it.. if unsure, I would recommend getting someone experienced with the car, and the cars electrical system to check it out..
Sucks, good luck, and feel free to email me if you have any other issues!
BTW, How is Los Altos this time of year? I am feeling a vacation coming.... need some space from things, and time to clear my head.. and I love playing with the electrical systems on these cars...
OH, and is it possible the starter wires are resting on the chassis or the bellhousing, or the alternator is shorted? disconnect the wires from teh alternator to issolate it.. check for a HOT wire touching the chassis of the car!
As for the harness still connected to the stereo.. is it the antena wire?
Thanks for your reply
To answer a few of your questions
First the goal is to just confirm that there isn't a short
This all started when I was considering getting a switched hot lead, for the MAF
I toyed with the idea of using that harness ( the little black box) on the drivers side firewall. I opened it up, and then decided it was too much wk to unsolder and solder the red striped wire. So, I closed it back up, and put thinks back. I then was testing the leads in the test port to confirm the correct one and noticed that I was getting continuity with the between the two battery leads!!?? Is that supposed to be the case ?
This is the main question ????
I do have a set of drawings ( wk shop manuals )
with the powered antena amp for one..
the power and ground both reading to chassis isn't suprising.. lots of variables there..
the power and ground both reading to chassis isn't suprising.. lots of variables there..
1) If you suspect a short.. with the meter connected to the battery cables, go to the fuse panel and one at a time remove each fuse and relay, if the short goes away you found the bad circuit
2) using the electrical schematics you can trace the wires for that circuit until you find the short IF it is in the wiring, if the wiring is all good it is either the relay or component in that circuit (any switches turned on?)
I was wondering if the alarm could be in a switched relay position and causing this ??
3) electrical diagnosis and repair can be a royal pain in the *** for someone experienced with it, and a total nightmare for someone NOT familliar with it.. if unsure, I would recommend getting someone experienced with the car, and the cars electrical system to check it out..
BTW, How is Los Altos this time of year? I am feeling a vacation coming.... need some space from things, and time to clear my head.. and I love playing with the electrical systems on these cars...
OH, and is it possible the starter wires are resting on the chassis or the bellhousing, or the alternator is shorted? disconnect the wires from teh alternator to issolate it.. check for a HOT wire touching the chassis of the car!
The car was shortless ( not that I know it;s a short ) when I started working on it .... So I am at a loss ....
Thanks again for your help
Regards
Ed
12-29-2010, 09:24 PM
#5
Nordschleife Master
The alarm shouldn't be shorting the pos and neg bat together.. perhaps a door was open or the hatch was open and you are reading continuity through the dome light circuit (always on).
And no, you shouldn't have a short from + to - on the battery cables with the battery out... because if you hook up a bettery, it will drain...
You COULD have a short (not unheard of) in the ignition switch (unplug it to check).. easy part of finding a potential short is, when you unplug an internally shorted component, the bat cable short will disapear..
other than a bad component, it will require a little more leg work to find a short in the wiring.. it would require the back of the relay to be accessed, and read for continuity between each power wire and chassis ground untill you find the one shorted (unless they all are...) this would also require each relay and fuse to be out (easiest way to begin is read the continuity, start pulling relays first.. if the continuity is lost when a relay is pulled trace out the wiring for the circuit.. but make sure the hatch and doors are shut first...
OH, and I do house calls, but you are 3000 miles or so away... that is one hell of a house call... but does sound like a fun and interesting buisness model... try unplugging the alarm module and see if the short goes away..
And no, you shouldn't have a short from + to - on the battery cables with the battery out... because if you hook up a bettery, it will drain...
You COULD have a short (not unheard of) in the ignition switch (unplug it to check).. easy part of finding a potential short is, when you unplug an internally shorted component, the bat cable short will disapear..
other than a bad component, it will require a little more leg work to find a short in the wiring.. it would require the back of the relay to be accessed, and read for continuity between each power wire and chassis ground untill you find the one shorted (unless they all are...) this would also require each relay and fuse to be out (easiest way to begin is read the continuity, start pulling relays first.. if the continuity is lost when a relay is pulled trace out the wiring for the circuit.. but make sure the hatch and doors are shut first...
OH, and I do house calls, but you are 3000 miles or so away... that is one hell of a house call... but does sound like a fun and interesting buisness model... try unplugging the alarm module and see if the short goes away..
12-29-2010, 09:29 PM
#6
Rennlist Member
Thread Starter
The alarm shouldn't be shorting the pos and neg bat together.. perhaps a door was open or the hatch was open and you are reading continuity through the dome light circuit (always on).
You COULD have a short (not unheard of) in the ignition switch (unplug it to check).. easy part of finding a potential short is, when you unplug an internally shorted component, the bat cable short will disapear..
other than a bad component, it will require a little more leg work to find a short in the wiring.. it would require the back of the relay to be accessed, and read for continuity between each power and ground untill you find the one shorted (unless they all are...) this would also require each relay and fuse to be out (easiest way to begin is read the continuity, start pulling relays first.. if the continuity is lost when a relay is pulled trace out the wiring for the circuit.. but make sure the hatch and doors are shut first...
OH, and I do house calls, but you are 3000 miles or so away... that is one hell of a house call... but does sound like a fun and interesting buisness model...
You COULD have a short (not unheard of) in the ignition switch (unplug it to check).. easy part of finding a potential short is, when you unplug an internally shorted component, the bat cable short will disapear..
other than a bad component, it will require a little more leg work to find a short in the wiring.. it would require the back of the relay to be accessed, and read for continuity between each power and ground untill you find the one shorted (unless they all are...) this would also require each relay and fuse to be out (easiest way to begin is read the continuity, start pulling relays first.. if the continuity is lost when a relay is pulled trace out the wiring for the circuit.. but make sure the hatch and doors are shut first...
OH, and I do house calls, but you are 3000 miles or so away... that is one hell of a house call... but does sound like a fun and interesting buisness model...
As well as the front hood So that could be the cause ?
There is a small light in the read hatch, drivers side, what position is the switch supposed to be in, if you want it off ?
Thanks John
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12-29-2010, 09:39 PM
#8
Nordschleife Master
read hatch?
turn the dome lights to the middle position on them, this should be default off.. or unscrew the door switches and unplug the passenger side hatch support strut wire (it turns on the light in the hatch area)
yes, if the dome lights are in the "on with door open" position, and the doors or hatch are open it is a closed circuit and you will have continuity between the + and - battery cables.. the dome light and hatch area light are always powered.. as are a few other spots (ignition switch, DME relay, few oddities here and there like the clock etc...) .... and always powered...
turn the dome lights to the middle position on them, this should be default off.. or unscrew the door switches and unplug the passenger side hatch support strut wire (it turns on the light in the hatch area)
yes, if the dome lights are in the "on with door open" position, and the doors or hatch are open it is a closed circuit and you will have continuity between the + and - battery cables.. the dome light and hatch area light are always powered.. as are a few other spots (ignition switch, DME relay, few oddities here and there like the clock etc...) .... and always powered...
12-29-2010, 09:54 PM
#9
Rennlist Member
Thread Starter
Thanks
What ya never hear of a read hatch ccommonn 
OK the rear hatch...
If I just switch the position to the middle, I don't have to close it ?
As for the doors, I will just close them, and as for the front hood I already unplugged the whole light assembly, so I should be OK there ? ?
If I still get an closed reading, then I just close the rear hatch and check again
Its not east to open the rear hatch without the battery in the car
read hatch?
turn the dome lights to the middle position on them, this should be default off.. or unscrew the door switches and unplug the passenger side hatch support strut wire (it turns on the light in the hatch area)
yes, if the dome lights are in the "on with door open" position, and the doors or hatch are open it is a closed circuit and you will have continuity between the + and - battery cables.. the dome light and hatch area light are always powered.. as are a few other spots (ignition switch, DME relay, few oddities here and there like the clock etc...) .... and always powered...
turn the dome lights to the middle position on them, this should be default off.. or unscrew the door switches and unplug the passenger side hatch support strut wire (it turns on the light in the hatch area)
yes, if the dome lights are in the "on with door open" position, and the doors or hatch are open it is a closed circuit and you will have continuity between the + and - battery cables.. the dome light and hatch area light are always powered.. as are a few other spots (ignition switch, DME relay, few oddities here and there like the clock etc...) .... and always powered...
OK the rear hatch...
If I just switch the position to the middle, I don't have to close it ?
As for the doors, I will just close them, and as for the front hood I already unplugged the whole light assembly, so I should be OK there ? ?
If I still get an closed reading, then I just close the rear hatch and check again
Its not east to open the rear hatch without the battery in the car
12-29-2010, 10:31 PM
#10
Rennlist Member
Thread Starter
unplug the passenger side hatch support strut wire (it turns on the light in the hatch area
As for the front hood, I pulled the harness clip that connects to the light, as well as the bulb
I also already pulled that crapy clock, so I could replace the bulb, that blew out WAPITA
I did everything else, but to no avail ...
Still have a closed loop between the two battery cables ...
So I guess I need to start pulling the fuses ?
Thanks
Ed
12-29-2010, 10:44 PM
#11
Nordschleife Master
Do you mean the drivers side ? There is a wire on the drivers side strut
As for the front hood, I pulled the harness clip that connects to the light, as well as the bulb
I also already pulled that crapy clock, so I could replace the bulb, that blew out WAPITA
I did everything else, but to no avail ...
Still have a closed loop between the two battery cables ...
So I guess I need to start pulling the fuses ?
Thanks
Ed
As for the front hood, I pulled the harness clip that connects to the light, as well as the bulb
I also already pulled that crapy clock, so I could replace the bulb, that blew out WAPITA
I did everything else, but to no avail ...
Still have a closed loop between the two battery cables ...
So I guess I need to start pulling the fuses ?
Thanks
Ed
next is the fuses, one at a time until the short goes away (which it may not) then the relays... then start finding which power lead is shorted to ground...
Whats the condition of your battery cables? I pulled mine out of my 951 recently, and the cable jacket was crumbling in my hand...
12-29-2010, 10:55 PM
#12
Rennlist Member
Thread Starter
Passenger side strut has a little switch that contacts the strut rod when the hatch is opened, there is a wire, look at the bottom of the strut.. the wire on the drivers side is ONLY the rear window defrost... also try the ignition switch... it could either be in the on position, or internally shorted...
next is the fuses, one at a time until the short goes away (which it may not) then the relays... then start finding which power lead is shorted to ground...
Whats the condition of your battery cables? I pulled mine out of my 951 recently, and the cable jacket was crumbling in my hand...
next is the fuses, one at a time until the short goes away (which it may not) then the relays... then start finding which power lead is shorted to ground...
Whats the condition of your battery cables? I pulled mine out of my 951 recently, and the cable jacket was crumbling in my hand...
The rectums cut out everything, but 3 factory pieces, the antenna lead, then there are like 3 small plastic clips, that nothing goes into.
So, I believe they are not the issue? I will post some scary pictures in a short while
As for the Battery cables, they look and feel brand new ( no kidding ). There also isn't one drop of corrosion on the leads either... The cables are pristine
I will go check that strut and the ignition..
Where is the switch for the hood light bulb or does it just work off the headlight switch ?
Thanks John
Ed
12-29-2010, 11:06 PM
#13
Nordschleife Master
Before I answer I forgot to tell you that the radio harness is non existent
The rectums cut out everything, but 3 factory pieces, the antenna lead, then there are like 3 small plastic clips, that nothing goes into.
So, I believe they are not the issue? I will post some scary pictures in a short while
As for the Battery cables, they look and feel brand new ( no kidding ). There also isn't one drop of corrosion on the leads either... The cables are pristine
I will go check that strut and the ignition..
Where is the switch for the hood light bulb or does it just work off the headlight switch ?
Thanks John
Ed
The rectums cut out everything, but 3 factory pieces, the antenna lead, then there are like 3 small plastic clips, that nothing goes into.
So, I believe they are not the issue? I will post some scary pictures in a short while
As for the Battery cables, they look and feel brand new ( no kidding ). There also isn't one drop of corrosion on the leads either... The cables are pristine
I will go check that strut and the ignition..
Where is the switch for the hood light bulb or does it just work off the headlight switch ?
Thanks John
Ed
didnt you say the starter was out?
you could also try disconnecting the loose positive wires from the battery possitive, and issolate the one shorted...
hmmmmm... interesting... very interesting... let me sleep on it, and I will tell you if any idears pop into my head...
12-29-2010, 11:30 PM
#14
Rennlist Member
Thread Starter
Well, I just checked that wire on the strut .. it was broken off, from the sliding clip so that's a non issue...
The Fuses were all pulled ... no movement
I didnt do the relays yet .. Do these just pull out straight up ?
One of them says Attention in German or is that Danger?
Is that a capacitor ? Should I pull that also? There can't be anything stored it that, as there hasn't been anything going on with this car in over 5 yrs
The Fuses were all pulled ... no movement
I didnt do the relays yet .. Do these just pull out straight up ?
One of them says Attention in German or is that Danger?
Is that a capacitor ? Should I pull that also? There can't be anything stored it that, as there hasn't been anything going on with this car in over 5 yrs
12-29-2010, 11:40 PM
#15
Rennlist Member
Thread Starter
Hood light is only powered if the parking lights are on, hell check and make sure your light switch is in the off possition..
didnt you say the starter was out?
you could also try disconnecting the loose positive wires from the battery possitive, and issolate the one shorted...
hmmmmm... interesting... very interesting... let me sleep on it, and I will tell you if any idears pop into my head...
didnt you say the starter was out?
you could also try disconnecting the loose positive wires from the battery possitive, and issolate the one shorted...
hmmmmm... interesting... very interesting... let me sleep on it, and I will tell you if any idears pop into my head...
I did pull off a few already, as they were ATC inline fuses on the positive lead so I just yanked'em
Thanks John
Sorry to take up all your time
Goodnight
Ed