svetter84

Has anyone replaced there theft detterent system? When I open either one of my doors my interior lights do not come on? They havent been working for some time but one day everything was fine the one day it just stopped working. They work with the switch but thats all! Have looked in my shop manuals and says this is the problem. My question is who sell the replacement or do I have to go to a dealer? Thanks for anyones input!

MrRenoman

The Helms manual is really required to troubleshoot the system. It seems that the only things in common between the courtesy lights and the alarm system are the door switches, the diode module, and the fuse that feeds them. I doubt if the courtesy clock fuse is blown you wouldn't have power to the courtesy lights when you use the headlight switch. The gages fuse powers the dome light delay timer, so check that too. I'm not sure exactly what gauges the fuse feeds but if your gauges are working I'd think th fuse is good. If the fuses are good then I'd start at the door switches. The courtesy lights and the alarm system appear to be running in parallel with the door switches being the common ground point for both the circuit that triggers the dome light timer and the theft deterrent controller. Does the "key in ignition" chime work? If it does then the driver's door switch is grounding. If not, you might want to check the door switches by grounding the wires that are connected to them (both doors). They could be stuck open (stuck in the in position). Turning the headlight switch to turn on the interior lights is telling you that the power to the lights and to ground via the headlight switch is ok. This circuit also runs in parallel to the alarm system. The diode module I mentioned earlier is connected to the theft and courtesy lights. It's function is to provide a current path when the rear hatch is ajar and lights the hatch ajar light on the dash and the rear compartment lights. I don't think that is a problem but I wouldn't overlook it if everything else is checking out ok. As you can see, diagnosing the theft system without a manual is not easy. Hopefully with the above it'll get you started. Invest in the Helms manual it's worth every dollar. I may have overlooked something here and maybe someone else will chime in. I'm just looking at the helms manual the schematic and what I think should be checked first. Seeing how both systems may not be working leads me to the door switches. You didn't mention if the theft system was working or not. It would be good to know.

Art

svetter84

yes the alarm system work but dont recall if the key left in ignition sound works? will check tonight! Thanks for your input!!

dwj

From what you are saying it sounds more like the interior light delay timer is not working

MrRenoman

I have a timer if you need one, it's part number is 14080625. I don't know what the dealer want's but an online corvette parts seller wants around $80 NOS. You should test and troubleshoot first before throwing money at it. If you want to test the circuit wiring or bypass the timer you can do it several ways. The timer is taped to the wire harness under the passenger side dash. There are two pink (pink/white and pink/blk), three white and a black (ground) wire going to the timer terminal connector. Unplug the connector from the timer. There should be 12 volts on the pink/white wire all the time, and 12 volts on the pink/blk wire when the key is on. The single white wire goes to the lamps and on to 12 volts via the courtesy/clock fuse and the dual white wires connected together on the same terminal go to the door switches. If you ground the single white wire the courtesy lights should go on provided you have a fuse in the courtesy/clock fuse position of the fuse panel. You can ground it by jumpering the single white wire to the black ground wire (provided the ground is good) or to a known good chassis ground. Or connect all 3 of the white wires together (this will bypass the timer completely). You'll need to have the door open (which it will probably already be) and a fuse in the courtesy/clock position of the fuse panel. The door switch will ground the circuit (provided the switches go to ground when you open the door and the wiring at the door switch is connected). You'd be surprised how many times problems are chased to something simple. The door switches are kind of a pain to check because the way the switch is connected to the wiring of the car. You'll just have to isolate and test the wiring, switches and power to figure out if its the timer or not.
BTW, here's a link to the timer
http://www.corvetteparts.com/catalog...hKeyword=timer

95BLKVette

HAVE TO PUT MY 2 CENTS IN.

My 95 had a similar problem that was twofold.

Replaced both door closure contact switches...they stuck and prevented both the interior lights and alarm from working properly.

These are the little plastic nubs on the door edge near the lock assembly that should pop out when the door is opened. If you grab these and pop them out and things work, then that's your problem.

The other possibility could be the LH int light fuse. Its quite small I think ony 5 amps if I remember.....I put in a 7 amp replacement and never have had a problem since.

I hope this helps you, cause if the above aren't it your in for some real fun

MrRenoman

I hope svetter84 is dealing with an '84, if it's a later model it could be other issues like you mention. On the early C4s the small switch on the door edge is for the door ajar switch. From the schematic it doesn't appear to be part of the courtesy lights or alarm system.