WantAclean944?

I have been observing and searching these forums for some time now, trying to find some clue into my slew of electrical gremlins. So here are my mystery problems in order of most annoying, to least:
1)Bouncing Tachometer
2)Heater Either full on or full off (white plastic clips are there)
3)Passenger Side Window Sometimes Chooses to not work
4)Central Locking is Shot
5)Stereo Head Unit, although crappy, skips way easier than it should
6)Rear Defroster recently decided to stop working, mirror defrosters are ok though

BACKGROUND INFO: 87' N/A 944 Aftermarket alarm, ghetto rigged heater (silver toggle switch in picture below) Two central locking buttons, neither work (red below, next to heater toggle, and black towards top of picture near sunroof relay is) Subwoofer/amp/capaciter installed

<img src="http://img.photobucket.com/albums/v227/geoffhess/IMG_0672.jpg">

1) For 8-10 monthes the tachometer/gauges will be fine, but when that magical time comes, the tach bounces around like crazy along with the oil pressure, temperature and volt meter. Sometimes when I am playing music loud, the needles will bounce to that, other times, when I hit a pot hole or bump in the road, it will bounce to that, and sometimes it just goe to the beat of its own drummer, doing whatever it wants. I have also noticed that when it is being driven harder, it seems to show up.

2) The heater is now a "Freeze or Fry" situation now, either it is off and making my hands grow icicles from the ouside air (freeze) or it is on full blast, cooking me inside the cabin (fry). I bought the vehicle with the climate system like this; the only controlling unit is one silver toggle switch, which I explained earlier. Every once in a blue moon, the climate control system DOES work, but only once every 4 monthes or so, and for maybe only 25 seconds. I do have the the plastic clips>>>>


<img src="http://img.photobucket.com/albums/v227/geoffhess/IMG_0673.jpg">

Anything missing or possibly a vacuum leak?

3) The passenger window, on ocasion decides it does not wan to roll down with the switch on the passenger side, I then, being the drive have to use my switch on my side, all that is needed is a small tap on my switch and BLAAMO! the passenger switch magically works again.

4) The entral locking mechanism just does not work, I have two switches (see center console picture), and neither of them do their job. The previous owner said that when he had the car taken in for this, that there was "a short somwhere in the drivers side door." When either one of these buttons is pressed a semi loud clicking sound is made from under the passenger side dash, just one click for every time the button is pressed.

5) Do 944's just have bad stereo wiring because I bought a head unit replacement for the stock blaupunkt and although the new unit was not top of the line, it was by no means cheap. Whenever I go over the smallest bump, the stereo skips like a mad man. Maybe the connection is comming undone? but the screen remains lit so I know it is getting some power still.

6) As soon as it got really cold around where i live (northern california, more specific Yuba City), the rear defroster just quit on me, I inspected the wire strips in the back for any split or cut wires but found none under visual inspection. The side mirror defrosters still work though.

I really hope some of you more experienced porsche guys can help me out, some of these problems have become unbearable for me anymore. I know there are some very knowlegable people on these forums and i AM a newbie, so if I am asking retarded questions, please, take it easy.
Thanks in advance,
-Geoff

FRporscheman

Welcome to Rennlist!

Sounds like a bad ground somewhere. Clean these ground points: From firewall to top of clutch bellhousing (from firewall to the rear of the engine); on the frame rail RIGHT behind the driver-side headlight; battery. Others could point out other main ground points (If I missed any?).

For the window, try taking the switch out, take it apart and clean the contacts. Also, check the fuse for it.

The ghetto wiring for the heater is why it works on/off only. Get it rewired like stock and it should be good again. And the central locking doesnt work because of the aftermarket alarm.

jonnybgood

The rear defroster has contacts through the gas struts so check your connections through there. I have a spade connector on the passenger side and then I think there is a ground connection through the strut mount bolt.

Yeah, get rid of the extra switches and let the stock heater control unit do its job. The thermostat control works very well and compared to what you are going through now it will seem like heaven.

WantAclean944?

thanks for the help, and also, do you think that the grounds are the problem with my tach and gauges? or just the cd player....

83 TX 944

The ash tray looks like it's in bass ackards. Not sure though, mine is an early car. Do the newer cars have an light there? On mine it's linked to the cig lighter.

WantAclean944?

nope, that way is correct, it won't fit in the other way, and yes, it has a lightin there, i never use it though, just a place to hide receipts some times..haha

WantAclean944?

also, im sure there is a reason for the heater switch, if i were elminate the switch, the heater will stick on, so how do i go about fixing it back to stock?

Dmitry S.

Power windows are usually just a bad contact on the switch. Take out the 2 screws holding it in, and clean all the wires that plug into the switch.

RMills944

sand the contacts on the window switch and plug it back in and it will probably be fine. The grounds should be checked as well as the wiring.

The reason for the skipping is probably because of the crappy CD player. I'd recommend just getting a new one. That is not caused by wiring. Now, if the CD player was cutting on and off, that would be because of the wiring.

WantAclean944?

any help with wiring the heater back up or my damn tachometer? (those are the two issues that make me the most upset)

Granite 944

I've found that with electrical gremlins, it works best if one starts a systematic approach to it. It appears that a few if not a lot of your gremlins are poor ground connections and corroded/poor connectors along with the addition of some "creative" wiring by PO for the alarm and whatever else. I would start with finding ALL the main ground points on the car, clean/tighten them first (engine to body, main grounds near relay box, front frame ground points, and rear ground at rear lights). You might even consider adding a second grounding wire from engine to the body. That alone is the best place to start IMO, and WILL eliminate mucho problems and backtracking now, and down the road. Take a good hard look at the inside of your relay/fuse box, making sure corrosion on the contactors is not an issue. Eliminate any and all scotch connectors along the way. Solder/shrink tube them instead ( I HATE scotch connectors). Assuming your going to remove aftermarket alarm.......get the wiring diagrams for your car, study them, remove the alarm components, and reconnect wires accordingly. Check the cars operation at this point. If satisfied, continue on with one problem/circut at a time, checking fuses/relays/switches and for open wires. Scotchbrite/fine sandpaper/dielectric grease and rebending/tightening on all connectors is your friend, but dielectric grease not really good on things like window switches. Fractured wires not easily visable are not uncommon on wiring into doors and headlights. Bad switches/relay/resistor packs, not uncommon for heater. Check engine harness connectors for the oil gauge/water/DME/ref sensors, and the connections at the back of your cluster.
Factory manual with wiring diagrams, and Clark's Garage Index are good resources. Good luck!


Edit: Dielectric grease is ok IMO for the outside/fixed connector, but not for the inside of the switch. I believe the grease may contribute to carbon arcing on the contactors.

89AZ944

If cleaning the contacts on the window switch does not work, you may have to disassemble the switches and clean the contacts inside. Be careful as the plastic is a bit brittle (I had to replace one), but once inside, you will see where the brass contacts are blackened.

Twenty minutes with a little brasso or metal polish and ZING! Mine were working like new....

Peckster

The title of your post is kind of misleading, isn't it?

WantAclean944?

i was trying to state in a way that it seamed urgent and final that i needed to get my problems worked out. sorry if it was missleading