Headlight and Interior light Issues

Rickw wrote:

Eldo wrote:

BMD wrote:

Anyway, after I took it out, my headlights don't work anymore. So does that mean that my LCM does work and that something else is the problem?

No, it means that just about every light that used to be directly connected to the headlight switch, now runs through that module, and there is no direct connection between the switch and the bulbs... From a safety standpoint, that kinda' sucks, and it certainly makes it a mandatory part. The BCM does the same basic job for the interior lights.

I'm a bit confused on this thread now. So, are you saying the BCM has a problem or could the problem still be with the LCM.?

No, I was just mentioning that the BCM is the interior version of the LCM, running the door switches, seatbelt switches, courtesy lights, seatbelt light & chime, BRP, etc...

Maybe the BCM and LCM both went.

Did you jump start someone else's car lately? and did the problems start to occur afterward. Take a look in the owners manual about jump starting with the Riv, it's an eye opener.

Albertj

Its been years since I've had to jump start anyone. I swapped out the BCM with the one from the yard and there was no change. All the lights that were out, stayed out, but the rest of the cars functions are fine.

BMD wrote:

Its been years since I've had to jump start anyone. I swapped out the BCM with the one from the yard and there was no change. All the lights that were out, stayed out, but the rest of the cars functions are fine.

I forget if you tested the headlight switch, and I don't know if it matters anyway.

Once in a while we've seen a broken conductor in the wiring harness, would have to look at a wireing diagram but I wonder if there is one wire which, if broken, would cause this problem pattern?

Albertj

BMD, I was just re-reading this thread and wanted to confirm something: When you originally said your dash lights and 'perimeter' lights were out, you did mean the parking and marker lights, right?

By perimeter I mean that the only lights on the exterior that turn on when I start the car are the headlights. When the brake pedal is pressed the brake lights come on, and when I signal in either direction, the signal lights will flash.

10-4, that would be the markers & the parkers...

AlbertJ wrote: " did we ever ask if an aftermarket alarm.starter,or lock package was installed?"

Thats what AJ asked; its a valid question. being a great AJ fan,and a follower of his alter ego, LEANDER! http://leander-online.com, i would ask the same thing. but i know nothing about electronics? so ill keep my mouth shut.

BMD wrote:

By perimeter I mean that the only lights on the exterior that turn on when I start the car are the headlights. When the brake pedal is pressed the brake lights come on, and when I signal in either direction, the signal lights will flash.

the high beams are supposed to come on 1/2 bright as DRLs. If dark enough then the regular low beams come on with the side markers and tails.

maybe your problem is related actually to a dead sun sensor... it's shorted and thinks it's always light out and so won't let the LCM turn on the headlights... didn't we check for a dead sun sensor already?

Albertj

Robo, I already mentioned earlier that I have no aftermarket electronics in my Riv. Albert, the one thing that the LCM does turn on is the headlights (low beams).

BMD wrote: "Robo, I already mentioned earlier that I have no aftermarket electronics in my Riv"

ratts! dere i waz tinkin i wuz smaht....

Finally , my interior and perimeter lights ( or DRLs ) are working. But before I tell you what the problem was. I went through hell and back. OK, so at first I wasn’t sure if it was the LCM, Headlight Switch or Ambient Light Sensor. So, I though I would start with the LCM, since I read Matts’( L67 ) thread on another forum declaring that changing the LCM solved his lighting issues. This in fact is the LCM from my 96 Riv…



After my first trip to the yard, I came home empty handed in terms of an LCM but I did grab an exact match BCM. I installed in the car hoping for something to happen but no. Here it is…



I then located a 96 Olds Aurora at another yard. When I got there, I saw that the LCM was still in it. I pulled it out and noticed that the part number was different and it had a purple sticker instead of a blue one, if that means anything. In all other respects, it was identical in terms of connector configuration. Anyway, here it is...



In the mean time my Dad, opened up my old LCM. He touched up a few solder points and sprayed electrical cleaner on the legs of the four (spindle looking) coils. These legs are supposed to click in order for the DRLs to work.



Also, we saw this resistor that looked like it took a crap, but it is still working.



Anyway, got home from the yard and was ready to install the LCM from the Aurora. At this point I should remind you that the BCM in the car is the one from the first yard. After I installed the LCM from the Aurora, nothing happened, the car was the way it was before. So, being bummed out, I said lets see if my original LCM will work now that it’s been cleaned. I installed my LCM and the car just died !!! I had no functions, no ignition, no door locks, no lights of any kind and the BCM was faintly spurting out a sick sounding beep. At this point I was ready to smash my LCM against the wall . So, then I thought , I bet the BCM got tongue-tied reading the wrong LCM and now it’s confused. So, I put my original BCM in, left my original ( but clean ) LCM in and unhooked the battery for five minutes. After I hooked up the battery again, I put the key in the ignition and when I turned it over everything worked including my DRLs!!!! PHEWWW!!!!!!!!

Anyway, to sum it up, my DRLs were not working due to a malfunctioning LCM or Daytime Running Light module, as the dealer calls it. And for the record, the BCM is on the outside of the multi-use plastic bracket and the LCM is on the inside . I spent $50 on incorrect modules, but it beats spending the $375 the dealer wanted. Lesson, make sure the part numbers are identical before hooking up anything electronic. Aaron, I realize that this thread has become somewhat of a mess, so feel free to edit at will as some of it has become confusing for others looking for help. Anyway thanks to everyone here and hopefully this helps out someone else.

Boy, between the ECC head and the light controls, somebody at Delco sure couldn't size their resistors correctly...

Actually, could you elaborate Mark, because the value on that resistor is illegible and I think I will replace it. Are you saying it should be larger, if so what values would you recommend?

Glad to hear the fixed LCM was the cure!

BMD---> <---LCM

BMD wrote:

Actually, could you elaborate Mark, because the value on that resistor is illegible and I think I will replace it. Are you saying it should be larger, if so what values would you recommend?

I dont' think he means a different value in ohms, he means a different capacity in wattage. Maybe a 5W instead of a 1W?

And thank you for posting the saga - it's insturctive, probably should be left up, it may help people feel less apprehensive abut troubleshooting.

Albertj

Did you keep the Aurora LCM that you mentioned. If so, open it up and see if you can read the resistor value from that one. Your original LCM's resistor that looks overheated and has been sometime in the past, could not be read on the computer.
I would be thinking of replacing that soon. The sucker got very hot and is more than likely been weakened.
But I'm no electronics Tech either.

I did open up the LCM from the Olds, and it did not have that resistor. I was planning on swapping it out, but no luck. That should have been my first clue not to try it. If anyone has a 96 and can check the value of that resistor or take a pic of it would be greatly appreciated. Alternately, if anyone knows of another LCM for a 96, I may be interested.

If anybody knows of a LCM for a 98, I'd be interested. As long as it tests good.

- Albert is correct, I was referring to the power-dissipation rating of the resistors, not the ohms. Just like the new pictures posted of the ECC circuit board, it looks like this resistor is not a high enough wattage to keep from overheating.

- After you said that the Aurora LCM didn't have that resistor, and of course didn't work at all, I wonder if the Canadian Aurora had yet another circuit design... Remember, we only matched the Canadian Rivi to the American Aurora, and you presumably found a Canadian Aurora.

Probably best to drop it at this point...

Eldo wrote:

- Albert is correct, I was referring to the power-dissipation rating of the resistors, not the ohms. Just like the new pictures posted of the ECC circuit board, it looks like this resistor is not a high enough wattage to keep from overheating.

- After you said that the Aurora LCM didn't have that resistor, and of course didn't work at all, I wonder if the Canadian Aurora had yet another circuit design... Remember, we only matched the Canadian Rivi to the American Aurora, and you presumably found a Canadian Aurora.

Probably best to drop it at this point...

if the module is functioning, teh resistance should be in the ball park of correct.

Since it aint broke dont fix it BUT if you come across another working module, and it's resistor is unreadable, just desolder one end of the resistor and measure with an ohmmeter. Then use the next higher value as close as possible. For instance if it measures 355 ohms use 360. Also look at the underside maybe the color bands are readable there.

Albertj

I just replaced the ambient light sensor in my Riviera. My problem was the headlights were always on. Every once in awhile, they would turn off and my DRL's would be on. I could always tell when the DRL's were working correctly because my radio and mileage displays were at full brightness. When the headlights were on, those displays were dimmed, which made them difficult to read in the daytime. Sensor replacement fixed the problem.