90's Wiring Sucks
#1
90's Wiring Sucks
Please welcome a new, stubborn member in our family.
She is a 1989 928 S4 in what I believe is, Venetian Blue on Ivory Leather. We are now in restoration mode!
What literally has been done is a lot of looking at schematics, yelling at things, tapping at things, a multimeter, and a lot of contact cleaner.
There are some funny vids on my Instagram feed about this, such as this beauty:
:rofl:
Minor Victories:
- It's clean
- It runs well
- It's blue
- Power seats and mirrors now work
- Pop-up headlamps work
- Rear wiper mechanism isn't jammed anymore
Doesn't Work List:
- Door locks (ordered new set through Porsche)
- Hatch release from the inside (Bought hatch mechanism and gas shocks through Porsche)
- Rear wiper motor was jammed, and now it works. It just won't connect with the wiper itself now
- Memory seat function
- A/C even though it's full of freon
- Tail Light Failure error is on even though new bulbs are in it
- Aftermarket stereo sucks and one of the speakers is crackling
- Interior has seen better days (who ordered this? Liberace? White carpet)
- Cracked dashboard needs to be refreshed
- Dashboard bulb replacement
- Driver's window rattles
- Sunroof gear won't fully engage
- Hydraulic power steering reservoir/pipe has a leak
- There's a tube in the engine bay that doesn't really lead anywhere
That's the to-do list so far. :hitit:
Some pics:
WAT
Last edited by flipstah; 04-24-2016 at 11:33 PM.
#2
Rennlist Member
Joined: May 2014
Posts: 1,333
Likes: 215
From: Albany "the middle of nowhere" Missouri
Welcome! There is plenty of knowledge here and everyone willing to help! In regards to your taillight warning, make sure you have matched bulbs in each location side to side. It's very sensitive and can throw that error due to mismatched bulbs. Also make sure the rear side marker lights are good as you will get the error if one of them is out.
Also suggest you get to know the suppliers as they are a ton of help and are quite a bit cheaper than the dealer for just about everything!
Looks forward to following the progress!
Also suggest you get to know the suppliers as they are a ton of help and are quite a bit cheaper than the dealer for just about everything!
Looks forward to following the progress!
#3
+1!
Pick yourself up the Jim Moorehouse CD set from one of the vendors. Will save you lots of time & frustration in troubleshooting.
Search is your friend.....years of experience and lessons learned to be derived from others. I don't have a '89, but I've seen threads related to most of the issues that you mentioned.
Check out classic 9 leather for interior resto....great work out of that shop.
Also looking forward to seeing your progress! Welcome to the tank!
Pick yourself up the Jim Moorehouse CD set from one of the vendors. Will save you lots of time & frustration in troubleshooting.
Search is your friend.....years of experience and lessons learned to be derived from others. I don't have a '89, but I've seen threads related to most of the issues that you mentioned.
Check out classic 9 leather for interior resto....great work out of that shop.
Also looking forward to seeing your progress! Welcome to the tank!
#4
Thank you for the warm welcome! I have found Rennlist to be my Bible! It's where we got the thread on how to fix the locks temporarily until our new locks come in. It has the auto-lock feature, whether you like it or not haha!
There are many smart cookies around here and I look forward to chatting with all of you.
There are many smart cookies around here and I look forward to chatting with all of you.
#7
Welcome.
For the hatch release, my suggestion is that you buy a three-pack of air fresheners, and go through them all before proceeding. This approach has been working well for me, although I'm still on the first one.
For the hatch release, my suggestion is that you buy a three-pack of air fresheners, and go through them all before proceeding. This approach has been working well for me, although I'm still on the first one.
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#8
ROFL. Whenever we pull the release inside, it whirs and makes sounds. Just won't pop. Bought the lower hatch unit that houses the broken plastic casing so maybe, it'll solve that?
#9
+1!
Pick yourself up the Jim Moorehouse CD set from one of the vendors. Will save you lots of time & frustration in troubleshooting.
Search is your friend.....years of experience and lessons learned to be derived from others. I don't have a '89, but I've seen threads related to most of the issues that you mentioned.
Check out classic 9 leather for interior resto....great work out of that shop.
Also looking forward to seeing your progress! Welcome to the tank!
Pick yourself up the Jim Moorehouse CD set from one of the vendors. Will save you lots of time & frustration in troubleshooting.
Search is your friend.....years of experience and lessons learned to be derived from others. I don't have a '89, but I've seen threads related to most of the issues that you mentioned.
Check out classic 9 leather for interior resto....great work out of that shop.
Also looking forward to seeing your progress! Welcome to the tank!
928 dash removal is... Interesting.
Can anyone take pictures of their rear wiper motor and arm from the inside? The motor works but the arm won't go into the motor hole to function. Thinking it's either an arm replacement, or the bracket on the bottom is bent so it won't go into contact.
#10
#11
I did mine alone, but with the seats out for maneuverability. Mostly easy-peasy getting it out. Back in was a bit more of a PITA, since I didn't want to screw up the new leather, but it too was workable.
#12
If your hatch release motor is working, then the worst of the problems are covered. There's a "zip tie" solution, but a new insert may well solve the problem.
The wiper "connection" is pretty simple (again, if the motor is working, most of the problem areas are covered), the post goes into the hole. You can try to move the wiper by moving the part under the hatch. Mine was loose when I got the car, which was one reason the wiper didn't work (I had to chase through the switch and the relay too). It may be that the hatch isn't seating properly. The new insert may address this.
You can also try push down on the hatch (get someone big) while activating the wiper.
Dash bulbs are not terribly difficult. There's a link to Dwayne's Garage in the "New Visitor" sticky. There's a very good writeup on pod removal and bulbs in there. There's a ton of other info in the "New Visitor" sticky too.
Welcome.
The wiper "connection" is pretty simple (again, if the motor is working, most of the problem areas are covered), the post goes into the hole. You can try to move the wiper by moving the part under the hatch. Mine was loose when I got the car, which was one reason the wiper didn't work (I had to chase through the switch and the relay too). It may be that the hatch isn't seating properly. The new insert may address this.
You can also try push down on the hatch (get someone big) while activating the wiper.
Dash bulbs are not terribly difficult. There's a link to Dwayne's Garage in the "New Visitor" sticky. There's a very good writeup on pod removal and bulbs in there. There's a ton of other info in the "New Visitor" sticky too.
Welcome.
#13
- Door locks (ordered new set through Porsche)
- Hatch release from the inside (Bought hatch mechanism and gas shocks through Porsche)
- Rear wiper motor was jammed, and now it works. It just won't connect with the wiper itself now
Looking at the wiper mechanism you should see the drive motor's cam plate with a hole in it protruding from the hatch opening sill. The wiper has a plate on the underside of the hatch with a boss that should engage the hole in that cam plate. It is common for people to raise the hatch by turning out the rubber bumpers on the rear corners of the hatch in attempts to reduce hatch rattles and/or get the latch mechanism to work. They raise it so high, the wiper boss no longer engages the motor drive plate. The underlying problem is wear of some part of the hatch latch. You say you bought the lower latch. Make sure it has the white/yellow plastic insert intact. BUT a common problem is wear of the upper latch mechanism's plastic tongue. Wear there may not be obvious since it involves enlargement of the tongue's pivot hole that has a swaged pin passing through it. The tongue and pin are available. Anyway, check the height of the hatch relative to the hatch opening. They should be level with each other. If the hatch is higher than the body panels, trying turning the rubber bumpers back in until they are level and see what happens to the wiper. If you still have hatch rattles and the hatch release does not work after replacing the receiver, look at replacing the upper tongue.That solved my hatch problems, shown here:
https://rennlist.com/forums/928-foru...attle-fix.html
- Memory seat function
- A/C even though it's full of freon
Determine if the compressor clutch is engaging. If not, locate the single black wire that emanates from the front engine harness above the compressor and check that the connector there is intact. You can pull off that connector and determine if the harness wire is delivering 12V. If not, study the wiring diagrams and you will see that this circuit traces back through the 14 pin connector next to the jump post on the inner fender, then to the low pressure switch mounted on the drier in front of the condenser, then to a freeze switch mounted under the cowl cover at the back of the engine compartment before going to the climate control unit in the dash. You can check each junction for power and determine where it fails. It could be the jump post, a bad low pressure switch, bad freeze switch or the climate control unit. You can temporarily jump the pressure switch or freeze switch if you determine the problem is there. If the compressor clutch then engages and cooling takes place, you know the cause. If there is no power anywhere along the circuit, this generally points to a relay failure inside the control unit. There are lots of threads on how to replace that relay. Of course verify that the compressor clutch does engage and provide cooling if you apply 12V with a temporary jumper wire from the jump post.
- Tail Light Failure error is on even though new bulbs are in it
Make sure the sockets are not corroded. Bulbs should be matched pairs.
- Aftermarket stereo sucks and one of the speakers is crackling
- Interior has seen better days (who ordered this? Liberace? White carpet)
- Cracked dashboard needs to be refreshed
- Dashboard bulb replacement- Driver's window rattles
White plastic window guides can be replaced or snugged up with tie wraps. Upper felt pads may need attention and adjustment. Lots of threads on this.
- Sunroof gear won't fully engage
Is the problem in the gear box? Have you opened it up to see if it's just needs cleaning and lubing? It also helps to reduce resistance by CLEANING the tracks the sunroof runs on. I do not lube them because the lube there just attracts dirt and gums up the tracks again. Spray with WD-40 and wipe clean.
- Hydraulic power steering reservoir/pipe has a leak
In my case the low pressure return hose to the reservoir leaked due to compression of the end under the clamp so that it no longer sealed. I solved it by noticing the hose had a fair amount of slack allowing me to cut off a 1/2 inch or so of the compressed end and get a fresh section of hose to go under the clamp. No leak in many years. Of course, you can just replace that hose. If the leak is in a pressure line, it can be rebuilt or replaced.
- There's a tube in the engine bay that doesn't really lead anywhere
Give us a picture of that tube.
- Hatch release from the inside (Bought hatch mechanism and gas shocks through Porsche)
- Rear wiper motor was jammed, and now it works. It just won't connect with the wiper itself now
Looking at the wiper mechanism you should see the drive motor's cam plate with a hole in it protruding from the hatch opening sill. The wiper has a plate on the underside of the hatch with a boss that should engage the hole in that cam plate. It is common for people to raise the hatch by turning out the rubber bumpers on the rear corners of the hatch in attempts to reduce hatch rattles and/or get the latch mechanism to work. They raise it so high, the wiper boss no longer engages the motor drive plate. The underlying problem is wear of some part of the hatch latch. You say you bought the lower latch. Make sure it has the white/yellow plastic insert intact. BUT a common problem is wear of the upper latch mechanism's plastic tongue. Wear there may not be obvious since it involves enlargement of the tongue's pivot hole that has a swaged pin passing through it. The tongue and pin are available. Anyway, check the height of the hatch relative to the hatch opening. They should be level with each other. If the hatch is higher than the body panels, trying turning the rubber bumpers back in until they are level and see what happens to the wiper. If you still have hatch rattles and the hatch release does not work after replacing the receiver, look at replacing the upper tongue.That solved my hatch problems, shown here:
https://rennlist.com/forums/928-foru...attle-fix.html
- Memory seat function
- A/C even though it's full of freon
Determine if the compressor clutch is engaging. If not, locate the single black wire that emanates from the front engine harness above the compressor and check that the connector there is intact. You can pull off that connector and determine if the harness wire is delivering 12V. If not, study the wiring diagrams and you will see that this circuit traces back through the 14 pin connector next to the jump post on the inner fender, then to the low pressure switch mounted on the drier in front of the condenser, then to a freeze switch mounted under the cowl cover at the back of the engine compartment before going to the climate control unit in the dash. You can check each junction for power and determine where it fails. It could be the jump post, a bad low pressure switch, bad freeze switch or the climate control unit. You can temporarily jump the pressure switch or freeze switch if you determine the problem is there. If the compressor clutch then engages and cooling takes place, you know the cause. If there is no power anywhere along the circuit, this generally points to a relay failure inside the control unit. There are lots of threads on how to replace that relay. Of course verify that the compressor clutch does engage and provide cooling if you apply 12V with a temporary jumper wire from the jump post.
- Tail Light Failure error is on even though new bulbs are in it
Make sure the sockets are not corroded. Bulbs should be matched pairs.
- Aftermarket stereo sucks and one of the speakers is crackling
- Interior has seen better days (who ordered this? Liberace? White carpet)
- Cracked dashboard needs to be refreshed
- Dashboard bulb replacement- Driver's window rattles
White plastic window guides can be replaced or snugged up with tie wraps. Upper felt pads may need attention and adjustment. Lots of threads on this.
- Sunroof gear won't fully engage
Is the problem in the gear box? Have you opened it up to see if it's just needs cleaning and lubing? It also helps to reduce resistance by CLEANING the tracks the sunroof runs on. I do not lube them because the lube there just attracts dirt and gums up the tracks again. Spray with WD-40 and wipe clean.
- Hydraulic power steering reservoir/pipe has a leak
In my case the low pressure return hose to the reservoir leaked due to compression of the end under the clamp so that it no longer sealed. I solved it by noticing the hose had a fair amount of slack allowing me to cut off a 1/2 inch or so of the compressed end and get a fresh section of hose to go under the clamp. No leak in many years. Of course, you can just replace that hose. If the leak is in a pressure line, it can be rebuilt or replaced.
- There's a tube in the engine bay that doesn't really lead anywhere
Give us a picture of that tube.
#14
Interesting, but not impossible. Like many things on this car, take it slow and steady and it turns into a mostly easy job that just takes a while.
I did mine alone, but with the seats out for maneuverability. Mostly easy-peasy getting it out. Back in was a bit more of a PITA, since I didn't want to screw up the new leather, but it too was workable.
I did mine alone, but with the seats out for maneuverability. Mostly easy-peasy getting it out. Back in was a bit more of a PITA, since I didn't want to screw up the new leather, but it too was workable.
If your hatch release motor is working, then the worst of the problems are covered. There's a "zip tie" solution, but a new insert may well solve the problem.
The wiper "connection" is pretty simple (again, if the motor is working, most of the problem areas are covered), the post goes into the hole. You can try to move the wiper by moving the part under the hatch. Mine was loose when I got the car, which was one reason the wiper didn't work (I had to chase through the switch and the relay too). It may be that the hatch isn't seating properly. The new insert may address this.
You can also try push down on the hatch (get someone big) while activating the wiper.
Dash bulbs are not terribly difficult. There's a link to Dwayne's Garage in the "New Visitor" sticky. There's a very good writeup on pod removal and bulbs in there. There's a ton of other info in the "New Visitor" sticky too.
Welcome.
The wiper "connection" is pretty simple (again, if the motor is working, most of the problem areas are covered), the post goes into the hole. You can try to move the wiper by moving the part under the hatch. Mine was loose when I got the car, which was one reason the wiper didn't work (I had to chase through the switch and the relay too). It may be that the hatch isn't seating properly. The new insert may address this.
You can also try push down on the hatch (get someone big) while activating the wiper.
Dash bulbs are not terribly difficult. There's a link to Dwayne's Garage in the "New Visitor" sticky. There's a very good writeup on pod removal and bulbs in there. There's a ton of other info in the "New Visitor" sticky too.
Welcome.
- Door locks (ordered new set through Porsche)
- Hatch release from the inside (Bought hatch mechanism and gas shocks through Porsche)
- Rear wiper motor was jammed, and now it works. It just won't connect with the wiper itself now
Looking at the wiper mechanism you should see the drive motor's cam plate with a hole in it protruding from the hatch opening sill. The wiper has a plate on the underside of the hatch with a boss that should engage the hole in that cam plate. It is common for people to raise the hatch by turning out the rubber bumpers on the rear corners of the hatch in attempts to reduce hatch rattles and/or get the latch mechanism to work. They raise it so high, the wiper boss no longer engages the motor drive plate. The underlying problem is wear of some part of the hatch latch. You say you bought the lower latch. Make sure it has the white/yellow plastic insert intact. BUT a common problem is wear of the upper latch mechanism's plastic tongue. Wear there may not be obvious since it involves enlargement of the tongue's pivot hole that has a swaged pin passing through it. The tongue and pin are available. Anyway, check the height of the hatch relative to the hatch opening. They should be level with each other. If the hatch is higher than the body panels, trying turning the rubber bumpers back in until they are level and see what happens to the wiper. If you still have hatch rattles and the hatch release does not work after replacing the receiver, look at replacing the upper tongue.That solved my hatch problems, shown here:
https://rennlist.com/forums/928-foru...attle-fix.html
- Memory seat function
- A/C even though it's full of freon
Determine if the compressor clutch is engaging. If not, locate the single black wire that emanates from the front engine harness above the compressor and check that the connector there is intact. You can pull off that connector and determine if the harness wire is delivering 12V. If not, study the wiring diagrams and you will see that this circuit traces back through the 14 pin connector next to the jump post on the inner fender, then to the low pressure switch mounted on the drier in front of the condenser, then to a freeze switch mounted under the cowl cover at the back of the engine compartment before going to the climate control unit in the dash. You can check each junction for power and determine where it fails. It could be the jump post, a bad low pressure switch, bad freeze switch or the climate control unit. You can temporarily jump the pressure switch or freeze switch if you determine the problem is there. If the compressor clutch then engages and cooling takes place, you know the cause. If there is no power anywhere along the circuit, this generally points to a relay failure inside the control unit. There are lots of threads on how to replace that relay. Of course verify that the compressor clutch does engage and provide cooling if you apply 12V with a temporary jumper wire from the jump post.
- Tail Light Failure error is on even though new bulbs are in it
Make sure the sockets are not corroded. Bulbs should be matched pairs.
- Aftermarket stereo sucks and one of the speakers is crackling
- Interior has seen better days (who ordered this? Liberace? White carpet)
- Cracked dashboard needs to be refreshed
- Dashboard bulb replacement- Driver's window rattles
White plastic window guides can be replaced or snugged up with tie wraps. Upper felt pads may need attention and adjustment. Lots of threads on this.
- Sunroof gear won't fully engage
Is the problem in the gear box? Have you opened it up to see if it's just needs cleaning and lubing? It also helps to reduce resistance by CLEANING the tracks the sunroof runs on. I do not lube them because the lube there just attracts dirt and gums up the tracks again. Spray with WD-40 and wipe clean.
- Hydraulic power steering reservoir/pipe has a leak
In my case the low pressure return hose to the reservoir leaked due to compression of the end under the clamp so that it no longer sealed. I solved it by noticing the hose had a fair amount of slack allowing me to cut off a 1/2 inch or so of the compressed end and get a fresh section of hose to go under the clamp. No leak in many years. Of course, you can just replace that hose. If the leak is in a pressure line, it can be rebuilt or replaced.
- There's a tube in the engine bay that doesn't really lead anywhere
Give us a picture of that tube.
- Hatch release from the inside (Bought hatch mechanism and gas shocks through Porsche)
- Rear wiper motor was jammed, and now it works. It just won't connect with the wiper itself now
Looking at the wiper mechanism you should see the drive motor's cam plate with a hole in it protruding from the hatch opening sill. The wiper has a plate on the underside of the hatch with a boss that should engage the hole in that cam plate. It is common for people to raise the hatch by turning out the rubber bumpers on the rear corners of the hatch in attempts to reduce hatch rattles and/or get the latch mechanism to work. They raise it so high, the wiper boss no longer engages the motor drive plate. The underlying problem is wear of some part of the hatch latch. You say you bought the lower latch. Make sure it has the white/yellow plastic insert intact. BUT a common problem is wear of the upper latch mechanism's plastic tongue. Wear there may not be obvious since it involves enlargement of the tongue's pivot hole that has a swaged pin passing through it. The tongue and pin are available. Anyway, check the height of the hatch relative to the hatch opening. They should be level with each other. If the hatch is higher than the body panels, trying turning the rubber bumpers back in until they are level and see what happens to the wiper. If you still have hatch rattles and the hatch release does not work after replacing the receiver, look at replacing the upper tongue.That solved my hatch problems, shown here:
https://rennlist.com/forums/928-foru...attle-fix.html
- Memory seat function
- A/C even though it's full of freon
Determine if the compressor clutch is engaging. If not, locate the single black wire that emanates from the front engine harness above the compressor and check that the connector there is intact. You can pull off that connector and determine if the harness wire is delivering 12V. If not, study the wiring diagrams and you will see that this circuit traces back through the 14 pin connector next to the jump post on the inner fender, then to the low pressure switch mounted on the drier in front of the condenser, then to a freeze switch mounted under the cowl cover at the back of the engine compartment before going to the climate control unit in the dash. You can check each junction for power and determine where it fails. It could be the jump post, a bad low pressure switch, bad freeze switch or the climate control unit. You can temporarily jump the pressure switch or freeze switch if you determine the problem is there. If the compressor clutch then engages and cooling takes place, you know the cause. If there is no power anywhere along the circuit, this generally points to a relay failure inside the control unit. There are lots of threads on how to replace that relay. Of course verify that the compressor clutch does engage and provide cooling if you apply 12V with a temporary jumper wire from the jump post.
- Tail Light Failure error is on even though new bulbs are in it
Make sure the sockets are not corroded. Bulbs should be matched pairs.
- Aftermarket stereo sucks and one of the speakers is crackling
- Interior has seen better days (who ordered this? Liberace? White carpet)
- Cracked dashboard needs to be refreshed
- Dashboard bulb replacement- Driver's window rattles
White plastic window guides can be replaced or snugged up with tie wraps. Upper felt pads may need attention and adjustment. Lots of threads on this.
- Sunroof gear won't fully engage
Is the problem in the gear box? Have you opened it up to see if it's just needs cleaning and lubing? It also helps to reduce resistance by CLEANING the tracks the sunroof runs on. I do not lube them because the lube there just attracts dirt and gums up the tracks again. Spray with WD-40 and wipe clean.
- Hydraulic power steering reservoir/pipe has a leak
In my case the low pressure return hose to the reservoir leaked due to compression of the end under the clamp so that it no longer sealed. I solved it by noticing the hose had a fair amount of slack allowing me to cut off a 1/2 inch or so of the compressed end and get a fresh section of hose to go under the clamp. No leak in many years. Of course, you can just replace that hose. If the leak is in a pressure line, it can be rebuilt or replaced.
- There's a tube in the engine bay that doesn't really lead anywhere
Give us a picture of that tube.
Look at the bottom left corner of the engine. Mine is LHD so this is on the passenger side:
- Have to clean the sunroof gear box as it just gets stuck halfway. Haven't done it yet as that's priority two.
- The A/C clutch engages, so it might be a switch issue.
- Hydraulic steering pump had a clamp for the tube, which wasn't tight. Tightened and refilled with ATF Dexron. Monitoring.
#15
Your hatch receiver looks pretty warn. I got mine from here.
Sunroofs are a frequent source of frustration. Give everything a good cleaning, especially the guide tubes. I cleaned my cable like this. That, along with a good motor clean has things moving along nicely.
Sunroofs are a frequent source of frustration. Give everything a good cleaning, especially the guide tubes. I cleaned my cable like this. That, along with a good motor clean has things moving along nicely.