MeanMachine350

I've been trying to address this problem before I start putting my door panels and carpet back in but can't get it to work right.

Here's the deal, the open rear hatch button in my center console works just fine, however, the buttons on both door sills have never worked since I got the car. The first thing I did was check the how many volts it is getting to the buttons and both checked out to be 12v. Second I checked to see if the buttons were bad but both checked out fine. Then I checked the voltage of the plug to the motor and it came out to 12v.

After everything seems fine I decided to unplug the relay and clean it a bit then both door buttons worked after that! But the weird thing is.. it will only work when the hatch is open but when it is closed, thus the hatch ajar button is pushed in, the buttons won't work. I've tried unplugging the hatch ajar button and it still won't work when the hatch is closed. I've tried bypassing it, no luck.

I tested the voltage of the plug to the motor when the hatch ajar button is pressed down vs. popped out, when it is out it gets 12 v but when pressed down it doesn't get anything?

Can someone tell me what I am missing here? I've also checked the fuses and relays and both are fine. I printed out a electrical diagram from alldata and it shows that the buttons on the doors are connected to the dome lights system but I don't know what to check into that.

Any help appreciated! I'd like to get this fixed as soon as tonight.
-Cal

MeanMachine350

Could it be another relay somewhere in the car or is the hatch ajar button bad?

383vett

Maybe I'm misunderstanding what is going on. In the real world, you can't reach the switches without opening the door, so I'm not sure it matters that there is no voltage going to the switches when the doors are closed. When you first checked the switches, you could have shorted the 2 wires to bypass the switch to see if it triggered the relay to open the hatch.

Hooked on Vettes

In order for either door hatch switch to work, the courtesy light
delay timer module must be working.

If you open either door do the foot well lights, door lights and
cargo lights in the b pillar come on?

If not, could be sticking or bad door jam switches or
bad courtesy light delay timer module.

If the lights come on, verify the following.

Open the rear hatch.
Close both doors.
Press down on the hatch ajar switch.
After 30 seconds all interior lights should go out.

If they do.

Release the hatch ajar switch.
Only the cargo lights should come on.
Press down on the hatch ajar switch.
The cargo lights should go out immediately.

MeanMachine350

I meant the rear hatch glass in that case. When it is closed, the switch on the door won't work. Also I already tried shorting the wires to bypass the switch and it didn't trigger the relay when the rear hatch glass was closed. Sorry for the misunderstanding

MeanMachine350

Good question, If I remember correctly only the rear halo lights come on when the rear hatch is open, but I don't think the foot well lights come on when the doors are open. I'll have to check when I get home from work.

I remember last year I had a problem with the door jam buttons sticking since the alarm kept on going off. I'll have to look into that. Thanks for bringing the attention to that area!

MeanMachine350

After work today I tried opening the doors to see if the foot wells lights come on. I open the door and..... no lights. Checked the fuse and tried putting a new one in but no luck. Where is the dome light delay timer located at so I can check that?

Cliff Harris

On the '86 it's taped to a wiring harness near the ECM. It might be in a different location on your car.

Another thing to look at is that the car must be in Park or Neutral (automatic, obviously) to open the hatch. I don't know if there are similar gear restrictions if you have a manual trans. That means that there is another switch involved that could be a problem.

You should be able to hear the hatch solenoid relay clicking even if the hatch doesn't open. It's buried in the wiring under the rear surround, wrapped in foam rubber.

braeburn22

try turning on the interior lights with the headlight switch ( turn anti clockwise past detent) then try the door switches, if they work now, by pass the light timer by bridging the connection between the white wire and the 2 white or yellow wires from the door switches.

I had the same problem on my 89 and this fixed it just fine.

jeffp1167

On my 90 if they keys are in the ignition or turned on it won't pop the hatch. When I bought the car the passenger side would never work but after those door ajar switches were replaced it started working agin

MeanMachine350

I am suspecting that the door ajar switches are the problem.. because I had a huge problem with them last year since my alarm kept on going off since it was sticking so I just stopped locking the car.

But the main reason why I believe this is because when the rear hatch glass is open, the door switches work on both sides but closed it won't work. So if I am right, when the rear hatch glass open it activates the dome light delay timer, thus allowing the door switches to work.

Correct me if I'm wrong anyone. Is there a good way to fix the door ajar button to prevent it from sticking or just replace it?

jeffp1167

just replace them, I think they are like 30.00 a switch.

MeanMachine350

I found the door ajar switches on corvettecentral but it looks like I'd have to buy the boot also, I don't remember seeing a boot on those switches?

Black84

I had the same problem on my '84 that you are describing here. I found that when I turned the headlight/dash light switch counterclockwise until the interior lights came on the door panel switches worked. In the end I had to bypass the courtesy light timer to "fix" mine.

GREGGPENN

My 89 FSM shows the door hatch release switches sending a ground to the courtesy light timer. Inside there's a relay that's entergized when the door's are open. (Probably a fail safe in case of jittery door switch).

When the relay is entergized, the incoming voltage (white wire on terminal A) is allowed to pass thru to the black wire on terminal B. That's a connection to ground.

So, if the internal relay on the courtesy light timer is bad, your hatch release won't work. I'm guessing it only works when the hatch is open. It's also supposed to work when the doors are open. Once you get to the CLT, jump a wire from term A to term B to see if that's your problem. Consider that one possible (permanent) solution.

The courtesy timer is the PITA to get to. I'm pretty sure you have to remove the passenger kick panel. Dropping the ECM will provide more room to see. Even after you locate it (strapped to the main wiring harness), you won't get a ton of slack when untied).

The good news is Wilcox sells courtesy light timer boards. I think they're $20-$30. It's only about 2" x 2" x 1/2". I've seen them in black plastic (shells) or white.

I have a spare one that's black if you need a pic to aid in identification.

MeanMachine350

Okay.. last night I found both door ajar switches stuck inside, so I pried them out and lubricated it so it won't stick again and then tested the open hatch switches and they still don't work. Checked the voltage coming to the door ajar switches and both are 12v. Bypassed it but still no luck.. this is frustrating me.

I think it's a done deal the couresty delay timer is bad.. GREGPENN can you send me a picture so I know what to look for when identifying the timer and also what wires to bypass to make it work?

Thanks for your help guys. I've had three friends come over, asked for help on the forum, and a 6 pack of beer.. and that still didn't get the dang problem fixed.

MeanMachine350

My apologies, I completely missed your post. I did what you said and lo and behold.. the hatch switches works! What color wires did you bypass to make it work? Do you have a picture because that would be really helpful.

braeburn22

Hi

Connect the white wire at Terminal A to the 2 yellow wires connected at terminal D, this will completely bypass the timer.

GREGGPENN

Look here for pics of the various courtesy light timers and what they look like. Again, I believe Willcox carries replacements.

GREGGPENN

I believe this "function" may be described in the link I just provided above.