ECM- courtesy lights
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 862
Likes: 0
From: Lewisvlle NC
ECM- courtesy lights
88, 35th anni. automatic. Replaced ECM and PROM which corrected the problems I was after. High idle, coolant fans not working ,etc. All is great now, except my courtesy lights won't turn off. Pulled the fuse to get them to turn off and that worked. But, when I turn on the ignition and, or start the car ,they come back on and won't shut off, even after 30 minutes of driving. This happens even with fuse out. I am missing something, but don't know what. They will shut off when turning off ignition. Any ideas ? Thanks.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Sounds like you may have pulled on some non computer related wiring when you removed/installed computer. Perhaps they hardware for the lower hush/knee bolster panel creating a problem. If this stuff if all you messed with then it might be a good idea to go back and retrace your steps by dropping the passenger side panel and taking a look.
Drifting
Joined: Jun 2010
Posts: 1,853
Likes: 8
From: Westerly RI
Not quite clear on fuse in/out 
...I think you said, lights stay on with the key off until you remove the fuse, then they go out. But when the key is on, the lights stay on with the fuse out- correct?
Could you have possibly pulled the wrong fuse? Not always easy to see which label goes to which fuse, I've made that mistake.
If the lights work with the fuse out, you could somehow have a short to B+ in the power side of the circuit, crossed wiring, or something. May or may not be related to the ECM replacement, but 9 times out of 10 a problem that appears after making a repair is related in some way to the work done.
If I've misunderstood, and the lights will not go out unless the proper fuse is pulled, you could check the various switches that turn the lights on- doors, hatch, headlight switch to see if any one of them is stuck closed.
...I think you said, lights stay on with the key off until you remove the fuse, then they go out. But when the key is on, the lights stay on with the fuse out- correct? Could you have possibly pulled the wrong fuse? Not always easy to see which label goes to which fuse, I've made that mistake.
If the lights work with the fuse out, you could somehow have a short to B+ in the power side of the circuit, crossed wiring, or something. May or may not be related to the ECM replacement, but 9 times out of 10 a problem that appears after making a repair is related in some way to the work done.
If I've misunderstood, and the lights will not go out unless the proper fuse is pulled, you could check the various switches that turn the lights on- doors, hatch, headlight switch to see if any one of them is stuck closed.
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 862
Likes: 0
From: Lewisvlle NC
Not quite clear on fuse in/out ...I think you said, lights stay on with the key off until you remove the fuse, then they go out. But when the key is on, the lights stay on with the fuse out- correct?
Could you have possibly pulled the wrong fuse? Not always easy to see which label goes to which fuse, I've made that mistake.
If the lights work with the fuse out, you could somehow have a short to B+ in the power side of the circuit, crossed wiring, or something. May or may not be related to the ECM replacement, but 9 times out of 10 a problem that appears after making a repair is related in some way to the work done.
If I've misunderstood, and the lights will not go out unless the proper fuse is pulled, you could check the various switches that turn the lights on- doors, hatch, headlight switch to see if any one of them is stuck closed.
...I think you said, lights stay on with the key off until you remove the fuse, then they go out. But when the key is on, the lights stay on with the fuse out- correct? Could you have possibly pulled the wrong fuse? Not always easy to see which label goes to which fuse, I've made that mistake.
If the lights work with the fuse out, you could somehow have a short to B+ in the power side of the circuit, crossed wiring, or something. May or may not be related to the ECM replacement, but 9 times out of 10 a problem that appears after making a repair is related in some way to the work done.
If I've misunderstood, and the lights will not go out unless the proper fuse is pulled, you could check the various switches that turn the lights on- doors, hatch, headlight switch to see if any one of them is stuck closed.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
I don't think you need restate anything. Go back and check your work.
If you want pull more fuses to see which other circuit is backfeeding the lights. Quite a few of the ciruits in your car have power all the time the relay, timers or computer controls (ECM/PCM) simply apply a "ground path" to complete a circuit. As mentioned above pull the passenger side hush panel (there a light and wiring mounted right into panel you might check there first) make sure you didn't bump or pinch any wires when you were in there before.
If you want pull more fuses to see which other circuit is backfeeding the lights. Quite a few of the ciruits in your car have power all the time the relay, timers or computer controls (ECM/PCM) simply apply a "ground path" to complete a circuit. As mentioned above pull the passenger side hush panel (there a light and wiring mounted right into panel you might check there first) make sure you didn't bump or pinch any wires when you were in there before.
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 862
Likes: 0
From: Lewisvlle NC
Thanks for advice. The hush panel is off as it needed removed to get the ecm out. Just can't find any loose wires. I agree with all of you tho'. If the problem wasn't there before the repair then it must be something that I caused. Grrr !
Team Owner
Joined: Jan 2003
Posts: 20,316
Likes: 246
From: Summerland B.C. Canada
Pull the gages fuse and see what happens.
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