87 Coupe, AT

I tried to find the reason why my back-up lights don´t come on and thought I´d take a look under the console plate and adjust the
switch real quick as this is reportedly a common problem.

Here is what I found:



All cables were cut off by one of the POs. The pink and green-white striped ones have been badly crimped to a blck and red one, both vanishing somewhere behind the a/c control. The blue and light green (for the reverse lights) are cut off, so are the other two (blk/wht striped and org/blk striped?) What are the latter ones for? I also don´t have lights on the gear selector, not even sockets...


I cut open the electrical tape on the harness next to the shifter a litte just to peep into it, hoping to find the missing wires there: nope! Unscrewed the HVAC control, hoping to get it out and find the hacked off harness: nope! Took off the drv side console carpet, well, partly (man, this is even worse than with the C3s! Is the seat supposed to come out??) and looked behind the a/c control and radio and found this:




It does look worse in real live as the photo doesn´t show all of the aftermarket radio wires... Somebody put in a Kenwood head unit and Rockford Fosgate speakers (the stereo is awesome! Loud as hell and very clear), cut off quite a bit of wires and left others disconnected.

What are the two grey connectors (pink wire and grey wire) for? What is the loose gry/ylw-striped wire for? This one is loose, it only looks as it was going to the grey conector, it is not.

The yellow and blue connector seem to be part of the factory stereo harness. I don´t want to mess with those as the stereo works ok.

And I still haven´t found the harness for the neutral safety switch. Where does this one run, on the pass. side of the console?

If all other fails: I was thinking about putting +12V (pin 15/ign on) to the blue wire on the connector and take the green wire and run it to the back of the vehicle into the reverse lights directly. Should this work if I can´t find the correct wires?

 

Forgot to ask: in Pic 1 there is a little blk connector w/two blk wires. What is this for?

 

This pic should provide a clue or two. I rewired my entire rear lighting using it.
Good Luck

 

Side note, does the stereo have a rear view camera? If so, they ask you to wire into the reverse lights so it only works when in reverse. May be why the PO cut the wires.

 

Great info, thanks, will help a lot!

So, if blk/wht and org/blk are for the safety neutral switch, what are purple and grn/wht for? The engine only starts when I connect those and the engine only starts when the gear selector is in P or N.

 

I will pull the pass side kick panel tomorrow, if I get to it.

 

Can this be for the automatic a/c only? I believe I don´t have that feature, only a lever from "cold" to "warm". Hence this connector would not have to get connected to anything, correct?

 

I have a fixed mast antenna, may be aftermarket. If so, the PO may have pulled that connector off of the factory wiring.

 

Will check, but there is no other connector near that I have found so far. May will do once I dig deeper into it.

 

Yap, don´t need those.



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No, this is a regular DIN Kenwood with CD, AUX and USB in. I believe it doesn´t even have BT.

 

PRNDL -- wiring and connector

Circuit 6- PURPLE (Solenoid)
Circuit 916 - DK GR/WHT (Fused AUX BOX HATCH)
Circuit 24 - LT GRN (B/U Lamp Feed)
Circuit 75 - DK BLU (Ignition ON/CRANK Fused)
Circuit 434 - OR/BLK (ECM Harness)
Circuit 435 - BLK/WHT (ECM Ground)

Do you have the correct FSM? If yes just find someone parting a car and get a PRNDL connector and as much wire forward towards the dash with it. Then just use the FSM to sort what you need to complete.

 

I'd think everything you need is likely in the 'wire bundle' left of console in the image. No need to pull/find the connector over at the right kick panel.

 

Great info, very helpful, thank you!

There is no wire bundle on the drv side of the console in my car. I have a smaller bundle running on top of it, just to the right of the gear selector and a bigger one over on the passenger side. This is the one I need to follow, I believe.


Help me out of my ignorance: What does the Park Neutral Switch (org/blk and blk/wht, currently disconnected) do? And what does the Neutral Start Switch (ppl and grn/wht, currently connected) do?

 

I mentioned 'in the image'. for harness bundle. Follow the 2-black (seat belt switch) connector forward. IHBD (DaveP85C4) had reasonable descriptions in what he's deleted. ORG/BLK & BLK/WHT are ECM - 'data'. How original is the drive line? The GRN/WHT in a coupe is in the hatch circuitry. You apparently don't have a FSM (Factory Service Manual) OR do you? I thought the images might 'help' him explain to you what he had described in his posts.

 

Yeah, too bad he deleted his stuff. Donno why, send him a message to understand.

Ok, what does the ECM do with the "data" from the switch? Apparently it´s not necessary for the engine to start and run.

No idea about the driveline, I bought the car as "stock", whatever that may mean. I did find, however, a small black box in the engine bay at the bulk head, reading "Tunesport Performance Module". I g**gled that and this seems to be a (wannabe) "fuel economy improvement device". I didn´t have the time to mess with this one yet. I did notice tho that there is a little stumble in the engine when going off a complete stop. I also noticed that the wheels start spinning even when I take off what I think is slow. I never noticed this that in my C3s, my C5 or C6, the latter ones both supercharged. But then again, it´s my first C4 so maybe that´s all normal.

 

Ok, it´s getting from bad to worse.

I pulled the pass side carpet in order to locate the cut wires/connector that I supposed might be behind the radio. Couldn´t find anything. I then pulled the console and compartment, again, no cut wires to be seen. I did however make out those two wires that the PO routed directly to the neutral safety switch (black and red). Those run on the drv side of the tunnel and directly up towards either the ignition lock or even further towards the bulk head. That makes me think that there must have been a greater reason for the solution he chose and why I can´t seem to find the missing wires.

So, there are two dark blue wires in the bundle coming down behind the radio on the pass side, but one is RH pwr window and the other one goes to the HVAC control. There´s also some light green ones, but those are all connected to something.

Does anybody know how the wiring to the park neutral switch is routed from the factory so I know where to look for it? I do have the FSM () but didn´t find the answer to this question yet. The schematics don´t necessarily need to match the actual routing.

 

OK, I found the place where those red and black wires from the neutral switch connector go. They route under the drivers foot well panel, below the steering column, over to the left-hand side kick panel, right at the A-pillar. There they splice into the factory colored purple and green/white striped wires. Those then go into a thick bundle of wires, going up further behind the dashboard.

If I now would only be able to find the original wires for the back up lights I’d be a happy man!

 

No luck in finding any cut wires on any harness. Instead I spliced into the LT GRN wire on Terminal F in C209 (RH side I/P, under fuse box) and DK BLU in C237 (Terminal N, IIRC). Ran the wires to the P/N switch connector, toggled the wires together, put the key to ON and the shifter to R et voila - There was light!

The car is back together, starts and runs as it should, B/U lamps come on in R - done with this one!

I would like to officially thank WVZR-1 for his advice and help not only on the forum. Thanks, Dave!