Headlight and Interior light Issues

Hello guys,

I am in the process of certifying my Riv for the road. It is a 96 3.8 supercharged with 200,000 kms. It presently does not have daytime running lights, a requirement for road certification. The previous owner directly wired the lights to circumvent the Lighting control module, because he had to replace two modules in two years. Here are my questions, if anyone can provide me with answers, I would greatly appreciate it.

1. What would cause the Lighting control module to die, twice in two years?

2. My hi-beams will not stay on, I can pull them back and as long as I hold them there the hi-beams stay on, when I let go they turn off. Is the multifucntion switch responsible for this or the lightinc control module?

3. My interior lights do not work when I open my door, are they linked in with the lighting control module? I can turn them on by pressing them, but they will not come on by themselves.


Thanks for any advice or past experiences. i don't enjoy wiring issues one bit.

Rod

just a shot in the dark from someone who knows nothing bout electric stuff,but you might have a grounding issue....i know of a buddy who had a similar prob,they found a grounding location totally corroded,prob solved.

Rodman wrote:

Hello guys,

I am in the process of certifying my Riv for the road. It is a 96 3.8 supercharged with 200,000 kms. It presently does not have daytime running lights, a requirement for road certification. The previous owner directly wired the lights to circumvent the Lighting control module, because he had to replace two modules in two years. Here are my questions, if anyone can provide me with answers, I would greatly appreciate it.

1. What would cause the Lighting control module to die, twice in two years?

do you know if the PO had collision damage repaired - sometimes wiring issues are a result of incorrect rewiring upon repair.

Do you know where the grounds are? Many of them are obvious some are not. To find them all the factory service manual (FSM) helps, the diagrams show you where they all are. Point is no kidding you need to find the grounds for the lighting control module (LCM) and fix them.

I am not aware of a service bulletin or recall concerning the LCM. I do not recall reading the LCMs on any year Riv were problematic.

Headlamp switch is still available from the dealer for around $210, you can find them new from GM discount dealers on line for around $125, and probably less used from Ed Morad (moradpartscompany.com), a recycler in Ohio. Point is the headlamp switch might be the failure point - put it to you this way, with the LCM running the automatic headlights I rarely use mine, a valet broke the knob (pulled too hard) - just that it would not surprise me to find the problem there. You will have to check it.

Rodman wrote:

2. My hi-beams will not stay on, I can pull them back and as long as I hold them there the hi-beams stay on, when I let go they turn off. Is the multifunction switch responsible for this or the lighting control module?

The LCM.

Rodman wrote:

3. My interior lights do not work when I open my door, are they linked in with the lighting control module? I can turn them on by pressing them, but they will not come on by themselves.

The LCM shares control of this lighting in parallel with the switches at the lights. For instance with the doors - in the door latch there is an embedded switch. When that switch closes it grounds a line to the LCM, which in turn grounds a line to the interior lamps that turns them all on. When you use a switch at a lamp, it just grounds it right there in effect.

I wonder if the real problem is that the PO had a door switch fail (in 10 years of ownership I have replaced both my latches due to door switch failure in each. So far it's a once-and-done repair.) and in order not to have the inside lights on all the time, disabled the LCM rather than replace it a 3rd time. Scenario would be the PO replaced the LCM second time and a week or 3 later the dome lights are stuck on; brings it to a mechanic, the mechanic disabled the LCM with an explanation -- rather than find the bad circuit.

Rodman wrote:

Thanks for any advice or past experiences. i don't enjoy wiring issues one bit.

Rod

You will need a copy of the FSM (to find ground locations and some "how its supposed to work" details, they are available relatively cheap used on ebay if you shop around, still available new from GM/Helm Inc.). You will also need a multimeter (they are cheap, around $25 for a decent one, get 'em at Radio Shack, Wal Mart, or on line via Google Shopping) to fix this one. In general you are unplugging the LCM and testing the wiring, looking for loose/missing/shorted pins in the connectors, checking the headlight switch, and checking if your embedded door switches are working properly.

Albertj

The ground for both door switches is behind the passenger side kick panel (G203).

Abaddon wrote:

The ground for both door switches is behind the passenger side kick panel (G203).

Is it possible that someone installed the wrong multifunction switch in a previous repair? The later switches on the Saginaw columns push forward to turn on hi beams and pull back to flash em.

Just wondering if someone put a wrong switch on (wrong although it fits) then disabled the lighting module to get it all working?!??!

Albertj

I thought of that. The Flash-to-pass has "it's own" circuit, and is fused as such. Makes sense on why it works and not the high beams (won't stay on). I was going to ask if the Multi Function switch clicks when pulled back to keep the high beams on.....

Guys thansk for the quick and excellent advice. Went to the wreckers today and got an LCM. I was very lucky, not many Rivs around here. I picked up the LCM for $15.00, when GM Canada wanted 395.00.

I also picked up another headlight switch and daylight running lights resistor (located inside fender behind the air cleaner). I am going to switch the resistor out (just in case). I am also going to go trace through the wiring.

Its still daylight, but it appears the new LCM fixed the daytime running lights, and the brights will now stay on. I will know better when I go for a drive. The interior lights still do not work.. I will check out what you guys have said.

Two more questions about the lights

1. With the interior light switch embedded in the door, do I have to replace the door handle or is it a switch that can be replaced on its own?

2. If you guys have any more ideas of what could contribute to the death of the LMC, I would like to hear them. I will check all grounds and connections as you have presecribed.

Thanks, this site/users have been very helpful.
Rod

Rodman wrote:

1. With the interior light switch embedded in the door, do I have to replace the door handle or is it a switch that can be replaced on its own?

2. If you guys have any more ideas of what could contribute to the death of the LMC, I would like to hear them. I will check all grounds and connections as you have presecribed.

The "door ajar" switch is part of the door latch mechanism, not the handle. I like it cause I can listen to the radio with both doors open without the dinging. I simply "latch" both doors with a screwdriver, and the LCM thinks they're closed

No ideas on what would cause the LCM to fry. Like anything else electronic, one little fart and it's toast.

I forgot about that resistor for the DRL's. That's a Canada only "option".

That last is a good point - a shorted DRL resistor could have been what was wiping out the LCM...

Here in the States, we got the DRL's in '97, and instead of using a parallel circuit with a resistor, the system switches the high-beams on in series, so they each only get half-power, the same way that the cooling fans run series for low and parallel for high.

In turn, this could have been a problem when they replaced the original LCM - the Canadian unit would be totally different from the U.S. unit, and someone may have installed the wrong LCM...

Eldo wrote:

That last is a good point - a shorted DRL resistor could have been what was wiping out the LCM...

Here in the States, we got the DRL's in '97, and instead of using a parallel circuit with a resistor, the system switches the high-beams on in series, so they each only get half-power, the same way that the cooling fans run series for low and parallel for high.

In turn, this could have been a problem when they replaced the original LCM - the Canadian unit would be totally different from the U.S. unit, and someone may have installed the wrong LCM...

This sounds Very Plausible.

Albertj

I find it a bit odd that you guys went to DRL in 97, we have had them since 88 or 89. We usually do not "beat' the US in auto safety regulations, we generally follow your lead. just an observation.

I switched out the resistor. But the PO said the LCM's would last a few months and then the interior lights would start to flicker and the headlights would intermittanlty work and then the LCM would completly die. | guess i will see.

I still have not been able to resolve the lack of interior lights turning on when I open the door. And also, the car has the blue headlight light bulbs, (not sure what you call them as i am the type of guy that keeps things stcok).

Could these higher performance headlights cause my LCM to die a slow death, if no updates to wiring has been done to provide more power to the bulbs?

Thanks guys

Quote :

And also, the car has the blue headlight light bulbs, (not sure what you call them as i am the type of guy that keeps things stcok).

Could these higher performance headlights cause my LCM to die a slow death, if no updates to wiring has been done to provide more power to the bulbs?

If it's the headlamps (outside lamps) there is reason for concern, as these blue bulbs are not stock equip. You may want to inspect the bulbs in question - check their wattage. 55-65W should be fine. 80W or more, it might be too much. If it's the DRL/brights (inside bulbs) I wouldn't worry too much - they operate at lower voltage during the day. If all the bulbs are blue, you might want to replace the headlamps.

I once had a problem with my lights flashing on and off rapidly when they turned on. I had a new set of bulbs handy and replaced them, problem solved. Even though the old bulbs still worked, after close examination I could see one of them had something wrong with the filament, like it had burned out and welded itself back together. Possibly it was drawing too much current. Anyway, no problems after that.

Rodman wrote:

I find it a bit odd that you guys went to DRL in 97, we have had them since 88 or 89.

Believe me, it was neither a vote nor a consensus decision... many cars in the US effectively had DRLs (my Volvo 740 and Subaru Legacy did) but they were implemented as low beam headlights that would turn themselves off if you had them on when yo switched off ignition. They would turn back on if you turned the headlight switch off then on while ignition was not on.

Rodman wrote:

I switched out the resistor. But the PO said the LCM's would last a few months and then the interior lights would start to flicker and the headlights would intermittently work and then the LCM would completely die. | guess i will see.

I think we already guessed you may have the incorrect LCM. We can not verify that for you, you have to do it yourself, sorry. You need to get the wiring diagram for your year/model (CDN) Riv and a parts list that shows the Canadian resistor and LCM, check and see that you have the right ones. Also look to see if someone changed your wiring in order, say, to get the US LCM to work in the Canadian car. Again -- I am speculating here. Point is you're going to have to do (much) more than put in a CDN LCM to fix this one probably. You are not likely done troubleshooting.

Rodman wrote:

I still have not been able to resolve the lack of interior lights turning on when I open the door. And also, the car has the blue headlight light bulbs, (not sure what you call them as i am the type of guy that keeps things stock).

Could these higher performance headlights cause my LCM to die a slow death, if no updates to wiring has been done to provide more power to the bulbs?

As for the doors, you will sit in the dark until you deal with the door switches and associated wiring. In other words, "asked and answered." I can't make you test the door switches, I can simply smile sadly while you avoid doing so.

As for the headlights, I don't know and I kind of doubt it, however, what you can do is pull out one of the headlights and look at the base, see what wattage is printed on it. If it's higher than 55 watts for lo and 60 watts for hi then the bulbs are using more power than normal, and it may be that as for the headlights that's the only problem -- the LCMs as I recall use SCRs and don't like being overdriven by much for long.

Albertj

Rod, do you have a set of the Factory Service Manuals?

I just remembered that the other G-body, the Olds Aurora, used a Low-Beam Resistor-type DRL system, and I'd wager heavily that that schematic would be helpful with your Canadian Rivi...

Eldo, the only difference between U.S. and Canada schematic is that he has a resistor wired into the DRL CNTRL line coming off of the LCM. That's it, that's the only difference lol. Wire comes off the LCM (Pin G, Gray wire, CKT 589), goes to the resistor (LF of engine compartment), turns Tan, and then on to the headlights. Weird actually. Don't know why they feel the need for a resistor in Canada.....

Abaddon wrote:

Eldo, the only difference between U.S. and Canada schematic is that he has a resistor wired into the DRL CNTRL line coming off of the LCM. That's it, that's the only difference lol. Wire comes off the LCM (Pin G, Gray wire, CKT 589), goes to the resistor (LF of engine compartment), turns Tan, and then on to the headlights. Weird actually. Don't know why they feel the need for a resistor in Canada.....

is the US LCM diff from the CAN LCM? (no fiche tonight, can't check)

Albertj

Not as far as I can tell....only the resistor shows as a Canada only part. It doesn't even make sense (by looking at the schematic) as to what it's for. That circuit goes from the LCM to the Dimmer Switch, and then to the Low beams (DRL's).
The only way it would make sense, is if Canada had (or has) some sort of law regarding how bright the DRL's are. That circuit powers the Lo beams. I would assume it's also turned on and off by the LCM given the conditions are correct via the Ambient Light Sensor, and that resistor would dim the lights.....

By appearance it's a bit confusing, but after studying the schematic that's what makes sense to me.

Abaddon wrote:

Eldo, the only difference between U.S. and Canada schematic is that he has a resistor wired into the DRL CNTRL line coming off of the LCM. That's it, that's the only difference lol. Wire comes off the LCM (Pin G, Gray wire, CKT 589), goes to the resistor (LF of engine compartment), turns Tan, and then on to the headlights. Weird actually. Don't know why they feel the need for a resistor in Canada.....

Actually, you just exactly described a '98 U.S. Aurora DRL circuit, right down to the colors and numbers, which is parallel and superfluous to the main low-beam circuit...

A '96 U.S. Rivi shouldn't have that circuit at all. Check out Timo's '96 schematic about 2/3 down this page:
https://rivperformance.editboard.com/exterior-f12/how-do-you-get-the-low-beams-to-stay-on-with-the-highs-t5215-30.htm?highlight=high+beam+low+beam

Eldo wrote:

Actually, you just exactly described a '98 U.S. Aurora DRL circuit, right down to the colors and numbers, which is parallel and superfluous to the main low-beam circuit...

You bastage You made me look it up. You ain't lyin. It's identical. So, I guess the question still left is wtf is that resistor for, and why on the Aurora, Eighty Eight, LSS, and Canada only Riv's?

This is where GM engineering Dept might be helpful.

I forget the actual name of the form's and type of request, but you could request assistance from them and they have the blueprints and system info that goes far beyond what is published for the mechanic in the field.
Abaddon you will probably remember the proper names and avenue's that could be taken to get that kind of assistance from them.

Only problem is you have to be working for a Dealership to get any help as far as I know.

Abaddon wrote:

Eldo wrote:

Actually, you just exactly described a '98 U.S. Aurora DRL circuit, right down to the colors and numbers, which is parallel and superfluous to the main low-beam circuit...

You bastage You made me look it up. You ain't lyin. It's identical. So, I guess the question still left is wtf is that resistor for, and why on the Aurora, Eighty Eight, LSS, and Canada only Riv's?

Because the fargin' iceholes who designed one circuit were dumber than the ones who designed the other...
As I've said before, the U.S. Rivi circuit works just like the cooling fans: Series for half-power and parallel for full power, without that extra resistor to burn out or corrode - and you get the aim of the high-beams at half-power for the DRL's, reaching out farther to the moron who is about to pull out in front of you...

Feel free to plus me...

Eldo is the Engineering Dept . He's absolutely right. The Aurora DRL's are wired into the low beams (with the resistor), and the (U.S.) Riv is wired through the High beams, with series config for the DRL's, and parallel for High beams. Just confirmed it with my own eyes

And, because you begged so superfluously (like that? ) , you deserve a +

Abaddon wrote:

Eldo is the Engineering Dept . He's absolutely right. The Aurora DRL's are wired into the low beams (with the resistor), and the (U.S.) Riv is wired through the High beams, with series config for the DRL's, and parallel for High beams. Just confirmed it with my own eyes

And, because you begged so superfluously (like that? ) , you deserve a +

Thank youuuuuuuuu...

Eldo wrote:

Actually, you just exactly described a '98 U.S. Aurora DRL circuit, right down to the colors and numbers, which is parallel and superfluous to the main low-beam circuit...

But I thought Eldo, the engineer said that the Aurora and ultimately the Canadian wiring had the resistor in Parallel and was superfluous because the resistor is in parallel.

If it is indeed in parallel then the resistor would do NOTHING in the circuit, it would have to be in series to cause a dimming of the low beams.

Noooooo, I said the whole DRL circuit "is parallel and superfluous to the main low-beam circuit... "