85 electrical problem

[c4ever]

Yesterday out of nowhere the door located hatch switches didn't work. Just a few minutes before that they were working, I know because I washed and waxed the car and used them both. In addition the interior lights do not come on when either door is opened? All other functions associated with this circuit work fine. Vanity mirror, hood lamps, door locks, etc. If I open the hatch from the console (which does work) the rear hatch lights do come on. If I manually turn on the interior lights(headlamp switch) they work fine. If the manually turn on the map lights (door) they work fine.
This has me stumped. Both sides going out at the same time. I can't believe it would be in the switches or harness. I did rempve the Bose for repair but removed it again today. Everything is fine. No pinched wiring. No sign of anything. Is there a specific point to go to rather than troubleshooting the entire circuit. This is a stock car with all original wiring in place.
;help ;help ;help

Carlo

 

[JonM]

Door looks not only work with the CTSY fuse but also the Power Acc Circuit Breaker. If these are both ok, check the relay behind the multiuse insterment panel...check the wires to the relay, it also has its own ground. The relay has a Light blue, 2 black, gray. tan and an orange/black wires running into it.

 

[Eagle85C4]

Actually, you might be having the same problem I had... The wires that go to the door jamb switches chaffed against the metal frame under the dash. Remove the switches and gently pull the wires out and see if the insulation is is still intact. I found this out when my drivers door no longer set off the security light when the door opened after I shut her down. I found the wire had been chewed in two. So I got some shrink tubing, spliced the wires back together and covered them. Now it works like new again....

 

[c4ever]

Thanks for the replies.

JonM: The door locks are fine, it's the hatch release and interior lights. Since the center console hatch release works I would assume all relays were operational.

Eagle,
I would agree but what is the chance of both doors going at the same time? That's what's so wierd. I know the interior lights are getting power because the headlamp switch/ manual operation for the interior lights works fine? Really strange.

I guess I'll start at the switches. I just don't think that is it. I must be overlooking something simple.
:confused
Thanks to all. I'll look at all your suggestions this weekend.

Carlo

 

[tbender]

Check the interior light timer located under the dash on the passenger side (see shop manual) If the timer goes out the interior lights will not operate nor will the hatch door switchs. However the console button will work. Also, it will work if you turn on the interior lights with the headlight switch

Mine failed on my 85 and It caused the interior lights to stay on so I removed it. I have not yet replaced it and I can open the hatch with console button and if I turn on interior lights with headlight switch. Also all other circuit work fine.

Good luck
Tom

 

[69MyWay]

This is all good advice here.

I think the problem is coming from the door pin switch. The rear hatch will not pop unless the doors are open from the door panel switch. I found this out when putting keyless entry on my 90. I had to end up running a ground in the door switch/keyless trigger point so the remote would pop the rear hatch when the doors were closed.

Anyway, long story short, either that timer relay has failed like the previous post, or simply one or the other door switches is hanging up. Try opening both doors, then fiddle with the door jamb switch and see if the lights don't come on. If so, you just have a stuck/dirty jambed up switch.

You may simply need a new switch, or maybe the wires have chaffed loose from the backside.

 

[c4ever]

Tom and Chris,
Thanks. Tom may have something. His scenerio is close to mine. I'll shoot for the timer as I have done a visual insp of the switches and everything looks in order. Hopefully it's easy to get to.
Tom are there any tricks to getting to it?
To the manual(the book of a thousand questions)

Carlo

 

[tbender]

Dome light delay timer is the correct lable. Not very difficult to get to. Like most things on the Vett small space to work in. Look on page Y - Car 234 of the shop manual under "Hatch Release" and note item 3 under troubleshooting hints. Also on same page the Component Location page notes where the timer is. Figure 173-2. poor diagram but it will get you in the right place.

Good Luck

Tom

 

[c4ever]

Thanks Tom.

Carlo

 

[c4ever]

1985
I went through all my manuals and cannot find the timer diagram, description or location. Can someone give me a general description so I know this thing when I see it.
Thanks,

Carlo

 

[vigman]

Pass side

Drop hush panel
drop some of the harness stuffed under there
little black box
taped to harness
5 pin connector
White
about 2 by3 inches
single circut board in plastic can
Vig!

 

[vigman]

Like this

Courtsey of Bro-Ken

 

[c4ever]

Thanks Vig.
You da man

I hope this is what it turns out to be.

Carlo

 

[c4ever]

Once again you guys hit the nail on the head. Special thanks to tbender for saving me a bunch of time and Vig for taking the time out to show me the way.
This place rules

Carlo

By the way, the timer module is discontinued but Ecklers turned me on to Coastal Corvette in T'ville. Parts out a ton of C4's Even has a Flowmaster set-up I may take. I love dealing with Corvette people. The dealer didn't even know what the part was and when I brought it in to the parts dept. the guy says it's discontinued. I said you're kidding and he replies "well what do you want it's an 85" Need I say anymoread ad ad