GM head lights

Wow, Now we are getting somewhere.!! thanks Now please advise how to do that.

Hi again, AS the original poster of the question, I like to say that we are getting a bit off track here. I'm not arguing for or against automatic headlights. Let them come on anytime GM wants them to. I as the paying customer I just want to be able to turn them off in a few specific situations. If they come on the next time I start the car fine. What is the problem with that?? Now, can anyone tell me how to turn them off when the specific need arises???

Simple solution, ready?

1) Snip each DRL headlight power wire about 6" back from the bulb and connect those wires to a "push to open" switch. 2) Route the return line from the "push to open" switch to the relevant wire of your headlight bulb plug. (i.e. the one you snipped). 3) Discreetly mount switch, depress & hold to keep DRL off.

Lights will operate as normal until you depress the button.

This recommendation is for "off road use only" as per liability blah, blah, blah.

Total cost should be no more than $10 & 1 hour max.

Wow, good idea, I could push my parking brake one click to disable ABS and actually be able to stop on a rough road.

Wow !! thanks. Thanks a lot. I'll find that wire opps, those wires and do it. Well, maybe I'll have a friend do it.

Can't help you there. I'm not familiar with any vehicle that applying the parking brake does NOT disengage the DRL's with the vehicle running.

mike hunt

Tim Dolan wrote:

On some GM vehicles the BCM will set a code with this solution and light the "Check Vehicle Soon" light.

| > >Hi again, | > > AS the original poster of the question, I like to say that | we | > >are getting a bit off track here. I'm not arguing for or against | automatic | > >headlights. | > >Let them come on anytime GM wants them to. I as the paying customer I | just | > >want to be able to turn them off in a few specific situations. If they | come | > >on the next time I start the car fine. | > >What is the problem with that?? | > >Now, can anyone tell me how to turn them off when the specific need | > >arises??? | >

| > Simple solution, ready? | >

| > 1) Snip each DRL headlight power wire about 6" back from the bulb and | > connect those wires to a "push to open" switch. | >

| > 2) Route the return line from the "push to open" switch to the | > relevant wire of your headlight bulb plug. (i.e. the one you snipped). | >

| > 3) Discreetly mount switch, depress & hold to keep DRL off. | >

| > Lights will operate as normal until you depress the button. | >

| > This recommendation is for "off road use only" as per liability blah, | > blah, blah. | >

| > Total cost should be no more than $10 & 1 hour max. |

Read your state vehicle lighting laws. I'd bet that they specifically state that the operator (driver) of the vehicle is the sole entity that is responsible for the operation of the lights. I'd further bet that mention of the the manufacturer (as having any legal role whatsoever in the decision of when lights should be on or not) is totally absent. GM is insinuating themselves in what the law clearly says is *your* decision, NOT theirs. Now, I don't have a problem with "auto" lights...however the operator has a legal right (in my opinion) to decide if they want total control or if *they* want GM to control the lights. The decision is not GM's to make (even though they apparently think it is based on their arrogant design choices to thwart the owners rights in the matter!).

GM know better than you...didn't you know that? ;-)

Uhm...on ABS equipped vehicles, activating the brake monitor light bypassing the emergency brake switch will disable the ABS system. Bad idea!!!

| >

| > mike hunt | >

| >

| >

| > 80 Knight wrote: | > >

| > > This may sound stupid, but with my '91 Bonnie, my Grandparent's '97 | Chevy | > > Lumina, and (IIRC) my Sister's '04 Grand Am, applying the emergency | brake | > > turns off all auto-light / DRL's...At least while the car is in | park...Just | > > a thought. | > >

| > > -- | > > 80Knight | > > --1991 Pontiac Bonneville SSE Sedan | > > --3800 V6 | > > --190,000 KM's | > > Bonnie's Website's: | > >

| >

|

He was probably referring to the emergency brake (speculation on my part). No matter, bad idea as that will deactivate the ABS system on most GM vehicles.

|

I don't know if with all GM's the DRL turn off with the parking brake, but if yours does, it would be much easier to install a switch in parallel with the switch on the parking brake. Then you would also have the reminder that they are off since the parking brake warning light in the dash will be lit.

Does it disable the ABS? :-) :-) I'll have to test this out!

Cool! I just looked at this group for the first time and had two questions, one of them was "how do I disable the ABS?" My ABS not only sucks on a rough road, but down a little hill with some loose gravel. The SOB brakes pulse away and the &*#@^$ G3500 van keeps going. I can't wait for rain so I can really test it out.

Try it you will find your ABS works fine

Eugene wrote:

Oh crap, that high didn't last long. So is there an easy way to temporarily disable the ABS? I'd love to have a panic button on the steering wheel for when I want to stop in situations where ABS makes stopping more difficult.

Thanks mate. Okay. I have not done the mod myself. I want to state that right up front. But, after a lot of reading and digging around the net, it has been stated that the light sensor is basically a photo resistor. Meaning, it has a resistive value which varies according to the incident light acting upon it. The BCM applies a voltage to it, and by sensing the voltage drop across it, can determine the resistance, and thus measure the light intensity. The trick, is to disconnect the photo resistor from the circuit. Measure the resistance across it with an ohm meter (while it is well illuminated!). Replace into the circuit a fixed resistor of equivalent value. Voila! The BCM "thinks" you are driving in broad daylight ALL the time and will not automatically turn on the headlamps. You of course, can still turn the lights on and off as you wish via the head lamp switch. Just like the good old days.

Now, a couple of more points on this. One thing that I thought of and have brought up to others in some forum somewhere, is that it is an ASSUMPTION that the sensor operates this way (as a photo resistor). There are other types of photo sensitive circuits which could be used to a similar end. For example, the "sensor" could actually be a photovoltaic cell, which generates a voltage based on the incident light acting upon it. The BCM could then "measure" a voltage through a small IC amp circuit which in turn trips a relay when the current goes high enough. Amplifying zero is zero, the normally closed relay would then make the headlamps illuminate. A small EMF (voltage) coming from the sensor, if amplified, could trip the relay to an open condition if it gets to threshold level, thus turning off the headlamps. That is one example of how the system _might_ operate besides the photo resistor method. When I made this point where ever it was being discussed, I was more or less told that no no, it really just is a simple photo resistor. Anyway, that is why I in my original posting in here on this I chose my words ("Replace the light sensor with a circuit that will always present the same electrical characteristics as the sensor does during daylight.") carefully.

Another po>Wow,