Headlight and Interior light Issues

BMD wrote:

The same box labelled LCM in my pic is labelled BCModule in your pic.

Right, thats why I am confused....Where did this picture come from?

It somewhere on the site, let me do a quick check and I'll throw up a link.

Ah, here it is...
https://rivperformance.editboard.com/parts-wanted-f23/lcm-lighting-control-module-for-98-99-riviera-t4595.htm?highlight=lighting+problems
Its out of Aaron's 98 FSM.

BMD wrote:

Ah, here it is...
https://rivperformance.editboard.com/parts-wanted-f23/lcm-lighting-control-module-for-98-99-riviera-t4595.htm?highlight=lighting+problems
Its out of Aaron's 98 FSM.

Well I wonder whats going on then...the 98 FSM and part number seem to indicate the position is on the inner side, while the 96 FSM points to the other side....I'm really stumped. Sorry I cant just remember what side it was on but it was nearly a year and a half ago

You've been a huge help Matt, thanks!

I have checked all visible grounds and connections aswell as every fuse on the car. I have narrowed it down to these three things... LCM, Headlights Switch and Twilight Sentinel Sensor. Am I in the ballpark here?, how can I eliminate two of the three? Also, I was wondering if the LCM or PCM need to be re-programmed?

BMD, I don't have the time right now (I'm swamped at work), but when I get home (about 6:30 EST), I'll post the diagnostic procedure for Headlights INOP, as well as the necessary diagrams/pin terminals for you. This way you (we) can narrow it down.

OK, thanks Scott. I am about the head out to a salvage yard to pick up an LCM.

Just to clarify...

What works - Headlights, Dome and Cabin lights. Break lights come on when the pedal is pressed and when I signal, the lights in the rear flash as well as the front marker flashes.

What doesn't work - Instrument Panel, Radio , HVAC lights aswell as the rear and side marker lights.

Well that kills my plan

Out of curiosity, did you check the INT LP (10A) fuse in the left side IP fuse block?

Do the door lights work when you open the door? i.e. the giant red one? How about the glove box light? The vanity mirrors? The "reading" lights?

I'll tell you why I'm asking if you check for me
Hopefully, that LCM cures your prob.

Well, got back from the yard. They had a 95,97 and 98 Aurora but no 96. Nothing was left in the 97 and 98. I took the two boxes that I found in the 95. One was incompatible and this is what the other one looks like....

Is that the LCM?

This one is an exact match, with one of the boxes in my car, but when I installed it, nothing happened, aarrgghhh! ?

Sorry for not getting back to you sooner Scott. Yes, the door lights, glove box, reading lights and mirror lights all work, and I checked the Interior Lamps fuse.

Isn't that the box that emits all the chimes, dings, dongs, bells and whistles.????????
I really don't know. I only say that because of the pattern of holes drilled in it.

Did you ever get the part number for the proper unit to make your life a tad easier when looking for parts.???/

Rickw wrote:

Isn't that the box that emits all the chimes, dings, dongs, bells and whistles.????????
I really don't know. I only say that because of the pattern of holes drilled in it./

I'd say so, especially because the BCM is the one that has a Diagnostic Mode that emits beeps, and tests the chime functions...

OK, so if the BCM emits chimes ( which that box does) then the LCM is the box in the pic below...

So using that P/N I will see if I can locate another, the only thing is, I'm still not sure if replacing the LCM will resolve this issue.

I would make sure that is the absolute correct P/N before replacing anything else.

Isn't there a thread or list on here with the P/N for your car.? If not check with the local GM dealer parts dept and just tell them the truth. You got a used box from the junk yard and you need to verify P/N's, they should help you out.

I hate to see you replacing parts you don't need to, especially if your not absolutely sure that is the problem.

Don't you have the FSM for the vehicle and the troubleshooting chart. That is what it will take to determine if your part is indeed good or bad and needs replacing. Just need to follow the book step by step.

Where are the troubleshooting charts located?

BMD wrote:

Where are the troubleshooting charts located?

Book 2 has all of the electronic diagnostic charts IIRC...I would post them from the online source I have but a lot of the steps refer to links to other pages so it doesn't really translate so well

Thanks for the info Matt, I will check out Book 2. I appreciate the effort though man!

This whole thing is kinda weird. The headlights work with the switch, but the sidemarkers don't come on? And the interior (IP lights) don't light up with the switch? It almost sounds like that Ambient Light Sensor, but if the IP lights don't come on, even with the HL switch......weird. You've got me thinkin about this and checkin all the wiring diagrams over and over! I know I could probably get you an LCM (used), but the shipping might not be nice. I wanna narrow it down before you start replacing shit though....

Aside from what I was thinking, if you do want to test circuits, including the LCM, I can still post the procedure and connector views for 'ya....I think it's time. Again, it would be when I get home. On my lunch I have to figure out why my Jimmy has no heat (Blower Motor ain't workin)

Did we ever ask if an aftermarket alarm, starter, or lock package was installed?

Albertj

albertj wrote:

Did we ever ask if an aftermarket alarm, starter, or lock package was installed?

Albertj

Very good point Albert, I don't recall anyone asking that question but it could very well be part of the problem and just a coincidence that all this stuff happened shortly after doing the LIM gasket change.
Aftermarket alarms seems to be one of the worst offenders of various electrical, lighting and starting issues.
I know some people have had good luck with them, due to purchasing a quality product and having an installer that knows the Riv's wiring and systems very well.
One person comes to mind is the Deekster (Derek) He has had a system with remote starter on his car for a long time and told me he has never had a problem. He attributes that to the Installer he knows and the quality of the product he purchased.

But from what we have read on here, it seems that 90% of the people with aftermarket systems have had very annoying problems. That's why I never bothered with a remote start, even though I would like one for the winter.

Thanks for the response guys. Nothing on the car is aftermarket. Its the original alarm system, head unit, I haven't spliced anything new into any wiring ( not really my forte ). The only thing I have done in terms of wiring was fix the broken mirror wires in the boot that goes from the door to the dash in the spring. But I did slide the boot out and moved the wires around, but that did nothing. Scott, don't feel obligated man, I know your busy, peopl have lives outside of their cars. If you do have time and can share some info, then great, if not, no worries. I really have no experience with testing electrical issues in cars, I mean I guess its never too late to learn, but I've been going over the wiring diagrams in book2 of the FSM, but I am just not familiar with the symbols. My dad is more proficiant than I when it comes to these things, so I could pass any info onto him when I see him next.

P.S. The headlight do work with the switch but I never have headlight switch off. In other words when I start the car my headlights come on right away, I don't turn them on. Although I've turn and pulled the knob, and moved the slider every which way to see if I can get it to work now.

Good luck with the Jimmy Scott!

Rickw wrote:

albertj wrote:

Did we ever ask if an aftermarket alarm, starter, or lock package was installed?

Albertj

Very good point Albert, I don't recall anyone asking that question but it could very well be part of the problem and just a coincidence that all this stuff happened shortly after doing the LIM gasket change.
Aftermarket alarms seems to be one of the worst offenders of various electrical, lighting and starting issues.
I know some people have had good luck with them, due to purchasing a quality product and having an installer that knows the Riv's wiring and systems very well.
One person comes to mind is the Deekster (Derek) He has had a system with remote starter on his car for a long time and told me he has never had a problem. He attributes that to the Installer he knows and the quality of the product he purchased.

But from what we have read on here, it seems that 90% of the people with aftermarket systems have had very annoying problems. That's why I never bothered with a remote start, even though I would like one for the winter.

Deek was lucky, far too many mechs including dealer mechs are too arrogant or distracted to figure out the Riv wiring. I have lost count of the number of mechs who have said to me, or whom I have overheard saying, they don't do electronics. And the number of stereo installers who don't really know what's going on with an alarm system much less the ground-switched-signalling that the Riv does in its electrics.

Albertj

OK, I confirmed that this is the LCM...(Matt you were right , it was on the inside, damn 96 FSM has it drawn up the way the 95 Aurora was layed out)!

The dealer calls it the Datime Running Light Module, $375!
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?

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.

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.?