can someone please help,lights turn on with switch not with doors,year 93.bought helms books ,looked at wiring diagram,when i jumpwhite wire to black lights come on . this is on the back of the relay socket, the relay does energize when i open and close door switch on passenger door. tried another known working relay from fog lights, same # as court. light relay,same results. just noticed today when i push the drivers door switch in and out i dont hear the relay cycling everytime but it does work the security light on dash. just bought car 2 weeks ago, its my first vette,trying to work out all the bugs.

 

Go to HELMSINC.COM and get a manual, it will be the best money you spend on your car. I have a manual at home and I will post what it says when I get home if nobody chimes in, but I am sure someone will.

 

Make sure that your detent buttons on the doors aren't broken/jammed in and stuck. A common C4 gremlin.

 

thanks for reply,buttons appear to be fine ,as i stated the pass. door button moves in and out and cycles the relay, i can hear the relay open and close when i push it in and out.is this button a double function switch or just a make or break contact?thought maybe ambint light sensor was bad but all other light dim funtions work properly. thanks again ----- just looked in helms book little **** at end of the switch appears to be out much farther than mine on car does this little shaft move independent within the larger part of the switch????????

 

I just got my helms books, I'll run the test see what codes i get,this stuffs all new to me, i use to work on cars years ago when you could open a hood and still see an engine and work on it without swearing too much!

 

I'm having a similar problem, except mine wont go out. They stay on with the car off and stay on with the car running, then shut off 15-20 minutes down the road.

Just bought a '94 yesterday and I'm working all the bugs out like you are.

 

my helms book says you may have a defective door key switch but thats just the first place to look do you have the books?also you have a 94 dont know if the wiring is the same my books are for a 93

 

Because the Passenger side door switch works properly, the problem could be the CCM, or the wiring from the CCM back to the Driver side Door switch or the switch itself.

1) When you open either door, the Door Ajar light in the Dash Cluster should light.

2) Another indication the door switch on the Driver side (assuming you have a coupe) is working, open the drivers door and on the back edge of the Door panel, is a switch to open the rear hatch. If you press down on the switch and the hatch opens, the Door switch is good.

Do you know if an aftermarket alarm is installed on the car? If so, it's possible they cut the wire going to the CCM ) Central Control Module from the Driver side door switch so they could control the interior lights. The CCM monitors both Door switches and provides the ground path to turn on the Courtesy Lamp Relay.

You also mentioned the Security light blinks when you open the Driverside door. That's another indication the Driverside door switch is ok.

To gain access to the CCM wiring harness is not easy. You need to remove the plastic panel that the footwell lamp is mounted to and then remove some bolts holding the carpeted metal plate above the steering column.

On the side of the transmission tunnel you pull a small piece of carpet back which will expose a plastic panel held on by two screws. Once the panel is removed I think you need to remove a bunch of bolts holding a side bracket. Once the bracket is removed, you'll see the CCM. It's a metal box with two cable harnesses plugged into it.

If you ground Pin C12 a Black/Yellow wire at the CCM the interior lights should turn on. If it doesn't the CCM is bad. If the lights turn on, there is a wiring problem from Pin C12 back to the Driver side door switch or the switch is bad.

 

thanks for reply,i studied my wiring diagram for this circut in my helms book pin d12 gry/blk wire to pin 2 of relay is what energizes the relay,apparently the ccm is grounding the circut properly or the relay would not open and close, i can hear the relay open and close when i push the door switches in and out maybe im wrong about this or im missing something, im kinda thinking maybe there's corrosion in relay socket on pin 4 which connects pin 1 to ground via switch in relay,when i jump pin 1 to 4 on back of relay socket lights come on.

 

If you have the Helms manual, look in the second book page 8A-114-2.

Look at the block diagram in the middle of the page of the CCM. There are two inputs. LH Door Ajar and RH door ajar. The CCM monitors these two signals. If either door is open, the Left hand Door switch or the Right hand Door switch will place a ground on the Input to the CCM.

Left hand Door switch is Pin C12 Black/Yellow wire input to the CCM and the Right hand Door switch is on Pin D16 Gray wire input to the CCM.

The CCM will then ground pin D12 Connector C1 (Gray connector) which will place a Ground on Pin 85 of the Courtesy Lamp Relay. This will cause the relay to close the contacts between Pin 30 and Pin 87 of the Relay and cause the interior lights to come on.

Since the Interior Light Relay operates properly when the Passenger door is opened, your problem can't be the Relay, Relay socket, Relay wiring or the wire from the CCM to the Relay. It must be the CCM is bad, wiring from Pin C12 Black/Yellow wire back to the Switch or the Switch itself or the ground wire for the Switch. That's why I asked if the Door Ajar Light comes on when you only open the Driver side door. (I think the ignition key needs to be in the run position before the Door Ajar Light operates on the Dash).

 

both switches do operate the door ajar light on dash,if the ccm was bad it woudn't open and close the courtesy lamp relay would it? That's why im thinking that when relay closes ,pin 1 and pin 4 are a complete circut to ground via pin 4.I know black wire on back of relay socket, pin 4 is a good ground, i cheked to see this by jumping pin 1 on back of socket to pin 4 and the lights came on.That is what's making me think there is corrosion in relay socket or bad connection.I'm looking at page 8d-32 when i'm making these conclusions.I guess if i would just totally bypass the relay socket and temporarily hard wire the relay with jumpers that would prove or disprove my assumption. It's very hard for me to get up under the dash with the lower panel off and get at the relay socket. I was in there once and couldn't get the socket off the mount, let alone look up in socket to see whats going on.I guess i could front and backprobe socket to see if there is continuity. thanks for your help.

 

Are you saying when the Passenger side Door Ajar switch is manually operated, you can hear the Courtesy relay clicking but the interior lights don't come on, and when you operate the Driver side Door Ajar switch you don't hear the relay clicking?

I was assuming when you open the Passenger side door, the interior lights operate properly.

If so look at page 8A-114-2.

There are 2 inputs to the CCM. One is pin C12 Black/Yellow wire from the Driver side Door Ajar switch.

The other input is Pin D16 Gray wire from the Passenger side Door Ajar switch.

If either input places a ground on either pin C12 or D16, the CCM will turn on the Interior lights.

From the Driver side Door Ajar switch, there is a Black/Yellow wire that goes to a Splice in the wiring harness (S201).

1) At the splice, one Black/Yellow wire goes to a Diode module which turns on the Door Ajar light in the Dash Cluster when the Driver side Door Ajar switch closes due to the door being open.

2)At the splice a Black/Yellow wire goes to the Hatch Release switch. With the Driver side door open, if you press the Hatch release switch located on the back of the driver side door panel (assuming you have a Coupe), the rear hatch should open.

3) At the splice a Black/Yellow wire goes to the PKE module. Passive Keyless Entry Module.

4) At the splice a Black/Yellow wire goes to the CCM Pin C12 from the Driver side Door Ajar switch.

So if the Door Ajar Light comes on when you open the Driver side door, that indicates the wiring from the Driver side Door Ajar switch is good up to the splice (S201).

So your problem must be.

1)There is a open in the wiring from S201 to Pin C12 of the CCM Black/Yellow wire.

2)The CCM is bad. To eliminate a bad CCM you need to gain access to the CCM wiring harness and ground pin C12. If the Interior lights come on there is an open circuit from Pin C12 to splice (S201). If the lights don't come on, the CCM is bad.

You need to understand there are two seperate inputs to the CCM that can cause the CCM to turn on the interior lights. One is the Driver side Door Ajar switch and the other is the Passenger side Door Ajar switch.

All the manual says about Splice 201 is that it's located Instrument Panel Harness, Lower Left Hand side of Instrument Panel. How that wire/circuit could be open is very strange. That's why I asked If you have an After market Alarm installed and maybe the installer cut the wire so the interior lights would operate with their setup.

(The relay socket slides off of the black plastic relay bar the holds the relay sockets in place).

 

thanks,next time i get under the dash i'll try to slide the socket off the bar. I thought i tried that the last time i was in there and it wouldn't budge.I have determined that both door ajar switches are working properly.No there is not an aftermarket alarm.I'm still leaning torward a problem in the socket itself since the relay is cycling properly and I have already ruled out a bad relay. I'll post when I get to the socket and check it maybe this weekend some time, that is if I have time, the show at carlisle is this weekend, first time going, looking forward to it!

 

I want to thank everybody for your help,I fixed the lights tonight.The relay socket had some minor corrosion in it. Cleaned the contacts and the lights came on!