prodadiv

Is there a timer that regulates when the interior lights go off
after the door is closed or is it just a spring activated switch.
I am having trouble with the lights staying on and any advice
would be appreciated.

Jet-Jock

Since there is no info in your profile, can you tell us what year model your Corvette is? Depending... you'll be looking at a fuse, relay, and CCM.

prodadiv

sorry about the lack of details. I have a 1990 auto.

Jet-Jock

Check the two courtsey light fuses with an ohm meter (DVM) there should be a 5a and 20a lower left side of fuse panel. With your instrument panel are you familiar with using the diagnostics mode to cycle the relay on and off? If so you can place it in that mode page and exercise the relay to see if it is functioning. Next consider the physical switches on the doors, you could have a faulty one. Does your year model have battery protection, that is if the doors are left open for a specified period of time the light automatically go out? If so, does that function work?

prodadiv

Yes it must have a btry safety because I think this is what is
turning off the lights after about 8 or so minutes. How do you get to the diagnostic mode. Please explain. Thank you for this great input.

Pete

corvette1989bham

The lighting function in controled by the CCM. It has diagnostics for the each door circuit,light timer, EVERYTHING. you really need a factory service manual. Lighting is determined by outside lighting, if you recently closed and open doors (diff. timers) also it wont turn on lights if you open and close doors in certain time frame. (to keep lights from draining battery)
not complicated with service manual .$50 on ebay

Jet-Jock

I'm not 100% certain on the 90, take a look at this pdf:

http://home.cfl.rr.com/laniplace/pdf...ode%20Pull.pdf

You should determine if you have a DTC code.

You'll need access to the relay (located behind the knee pad on the passenger side) and a test light. After identifying the courtsey lamp relay, you'll see a set of two relays towards the console, the courtsey lamp relay is the outer most of the two. The inner is for Fog lamps. The group of three to the right should be fuel pump, rear defog, and horn from inner to outer.

Also determine if the ambient light sensor is functioning. Cover the sensor on the DIC panel with dark tape and to simulate darkness. Connect a test lamp between terminal 5 (orange wire) and ground. On the relay there are four pins: 1 is signal to the map lamps, light switch, and cargo lamps; 2 is signal to CCM gray/black wire; 4 is black ground; 5 is signal to B+ through RH CTSY fuse orange wire. (yes there is no terminal 3).

A good ground should be on the side wall exposed when you remove the knee pad.

After connecting the test light term 5 and gnd, turn ignition ON. Does the test light turn on, yes check the resistance between terminal 5 and 2 with DVM. If the light does not turn on check the RH CTSY fuse. If fuse is good you have a poor connection or open. When you check the resistance (above), it should be between 50-80 ohms. Is it? Yes check continuity between terminals 4 and 2. No, replace relay. If it was Yes and when testing the continuity now you'll get to the part about using the CCM through the diagnostics mode.

To test the circuit relay for an open or short to ground, you should be able to command the CCM to cycle on/off to the relay. Connect the test light between terminals 2 and 5 of the relay. Ign OFF, put a jumper on the DLC connector (see pdf) G and A. Turn Ign ON, press TRIP/ODO button until 1.4 displays, in trip monitor area then rpess ENG/MET button until 10....0 dipslays in odometer when it says 10....0 its off on the relay and 10....1 its on for the relay. Note the test lamp when its On the lamp should be on. If its on continuosly you have a short in CKT 690. If the lamp is off when its suppose to be on, it could be a open in CKT 690 or a bad connection at the CCM.

More than likely you'll find the problem before you get this far.

corvette1989bham

Well, did you fix it?

Corvette Kid

Don't forget the switch on the hatch too, if a '90 has that.

JrRifleCoach

Don't forget the headlight switch.
You can turn the curt' lights on by turning it all the way left. Or is it right? Whatever!