FAQ: How to disable headlamps & daytime running lights?

i use my knob a lot since i dont have DRL's and love to show off the HIDs. has yet to come off or even feel like it is weak.

With that said, a friend of mine with a 97 riv has a broken knob. any place to get replacements?

maybe it's a 97 thing??

For me, at least once per day, lol. Not that often, but I do use it when towing the trailer. I also use it in the evening to turn the lights on before the daytime runners switch off.

I guess some of us are just fortunate to be equipped with better knobs than others.

Well, it's not a very good picture, even with the camera set on closeup, but here is how our headlight knobs are attached: with a little "friction-clip" that anchors it (until it strips) into the plastic knob itself...

"Traditional knobs" had a triangular shaft that was glued into the knob, and then went into the switch behind the dash panel and was held by a spring-loaded push-button... I admit that this problem could be fixed with some Crazy Glue, I'm just leery of doing it because I don't know what's back in the switch, and if I may ever need to remove it again.

Since I like DRL's to keep idiots from pulling out in front of me, and after 20 years of driving either this or the Eldorado I'm totally dependent on the Twilight Sentinel, I just hold the manual knob "cocked" on the rare occasion that I need to pull on it...

VJD2 wrote:

Write it up!!

I hate Day Time running lights. I was just going to ask about how to get rid of them.

ill get a start on that and post here when done.

Eldo wrote:

The only problems being:

- Getting to the sensor is a PITA
- You're also disabling your Twilight Sentinel
- The manual headlight knob is a POS that loves to come off...

if the rivs are anything like my park ave, just pop the black plastic panel thats around the sensor up, leave it intact and do as posted above.
about disabling the twilight sentinel, it doesnt bother me cause i hated my lights staying on without the car anyway but if you like them staying on= auto headlights it is.

first i would like to ask if there is any DRL fuse or relay anywhere in the rivs?
if there is a fuse, pull it
if there is a relay, tell me and we'll go from there.
if there is neither, still tell me and i will have to come up with a way to wire your cars like mine.

97 park ave wrote:

first i would like to ask if there is any DRL fuse or relay anywhere in the rivs?
if there is a fuse, pull it
if there is a relay, tell me and we'll go from there.
if there is neither, still tell me and i will have to come up with a way to wire your cars like mine.

I would say no, there isn't... Everything is controlled and powered by the LCM/Lamp Control Module. Therefore, just like my mods to the window and the seat/mirror memory, you have to 'fool' the module to get it to do what you want.

If you make it think that it is always sunny outside, by messing with the sensor, you will keep the twilight sentinel from working. If you tell it that the gearshift is always in Park, it will keep the DRL's from coming on, and also let you turn off the Twilight Sentinel with the spring-loaded switch position...

If you tell it that the gearshift is always in Park, it will keep the DRL's from coming on


how do you trick the car
my 97 riv has no fuse or relay to disable drl

I just looked at the schematic for a '97 Riv DRL's. There is a dark blue wire coming out of the LCM that controls the DRL's, thing is, it's ONLY connected to the right side high beam in place of a ground. The left side high beam has it's own ground, it's the power that the 2 DRL's have in common (in series). I suppose it may be possible to run a seperate ground from the right side high beam in order to disable the DRL's effectively and still have manual control of the high beams (cut the blue wire at the headlight harness, and ground the bulb, not the LCM side). This is all in theory, but by looking at the schematic it makes sense.

Thanks for the info!

Now......who is brave enough to try it??

Abaddon wrote:

I just looked at the schematic for a '97 Riv DRL's. There is a dark blue wire coming out of the LCM that controls the DRL's, thing is, it's ONLY connected to the right side high beam in place of a ground. The left side high beam has it's own ground, it's the power that the 2 DRL's have in common (in series). I suppose it may be possible to run a seperate ground from the right side high beam in order to disable the DRL's effectively and still have manual control of the high beams (cut the blue wire at the headlight harness, and ground the bulb, not the LCM side). This is all in theory, but by looking at the schematic it makes sense.

No, no no... Look at the schematic again, this time for the wire going to the LCM from the PRNDL!

no fuse, no relay, and grounded through the left headlight/LCM for DRLs...that is exactly like my car.

for no DRLs:

1. cut the wire that goes to the LCM from the drivers side high beam (ground for DRLs)
2. cap the end coming from the LCM
3. cut the low beam ground wire on the same side
4. splice the high beam wire coming from the light side into the low beam ground.

thats what i did to my car also almost 3 years ago and its still all okay

Eldo wrote:

No, no no... Look at the schematic again, this time for the wire going to the LCM from the PRNDL!

Ok.....from the LCM to the PRNDL is a light green wire that's connected to the Park/Neutral Position Switch on the trans.....it's labeled PARK IN on the LCM. This wire is also connected to the Memory seat/mirror module, the RFA, and the Brake Switch (also indirectly linked to the Shift Interlock through the Brake Switch). What are you suggesting?

OK guys, I'm sorry I wasn't more explicit, but I was really tired and this is the same theory as in my writeup on the Seat-Memory-in-any-gear... In fact, in an incredible piece of irony, the colors of the wires are the same on both modules!

To answer your questions, what I'm saying is: rather than cutting and splicing the (hi-amperage) headlight wiring, you can keep the DRL's from ever coming on by giving the LCM a constant (lo-amperage) Park signal.

- Pull the lamp control module.
- Cut that light-green wire at A8 two or three inches out from the connector.
- ScotchLok the other end of it onto that pink IGN input wire at A7.

Now, whenever the key is on, the LCM is going to think that the car is in Park, and it won't turn the DRL's on... Also, the Twilight Sentinel will still work, but if you push the lever all the way left and turn it off, it will stay off until you do it again, or until the next ignition cycle.

I agree with you that may work also, but if you look at the schematic, that light green wire is Ign voltage (in Park). When in Park, Ign voltage is supplied to the LCM through that wire. Since there is no ground on the circuit in Park, the DRL's cannot come on. When shifted out of Park, the module "sees" the voltage disappear and grounds the dark blue wire to turn on the DRL's.
Being that the dark blue wire between the left high beam and the LCM is only a "ground" signal, grounding that wire at the bulb to chassis will disable the DRL function and still allow the high beams to work.

I just think it's easier.

Both ways will work, and both will still allow full Twilight Sentinel operation.

Abaddon wrote:

I agree with you that may work also, but if you look at the schematic, that light green wire is Ign voltage (in Park). When in Park, Ign voltage is supplied to the LCM through that wire. Since there is no ground on the circuit in Park, the DRL's cannot come on. When shifted out of Park, the module "sees" the voltage disappear and grounds the dark blue wire to turn on the DRL's.
Being that the dark blue wire between the left high beam and the LCM is only a "ground" signal, grounding that wire at the bulb to chassis will disable the DRL function and still allow the high beams to work.

I just think it's easier.

Both ways will work, and both will still allow full Twilight Sentinel operation.

I think your basic premise is correct, but you phrased it incorrectly. When shifted out of Park, the LCM applies 12V to the dark-blue wire, creating the half-power, series-circuit that is the DRL function...

Isolating that wire from the LCM and grounding it will result in manual headlight operation working properly, but the Twilight Sentinel on 97+ models will still be un-defeatable.
.

Eldo wrote:

I think your basic premise is correct, but you phrased it incorrectly. When shifted out of Park, the LCM applies 12V to the dark-blue wire, creating the half-power, series-circuit that is the DRL function...

Not tryin to argue, but if I'm mistaken I would like to be corrected.....my question then is what is the light green High Beam wire (terminal B) on the LCM for? Maybe I'm not understanding the circuit.....

Abaddon wrote:

Eldo wrote:

I think your basic premise is correct, but you phrased it incorrectly. When shifted out of Park, the LCM applies 12V to the dark-blue wire, creating the half-power, series-circuit that is the DRL function...

Not tryin to argue, but if I'm mistaken I would like to be corrected.....my question then is what is the light green High Beam wire (terminal B) on the LCM for? Maybe I'm not understanding the circuit.....

Ahhh, here's where my electronics degree comes in handy...

The smaller light-green wire that we were originally talking about is the Neutral-Switch to LCM wire, which is only a control wire. The larger light-green wire is the "normal" positive-to-high-beam wire, when the DRL output from the LCM is switched to ground, instead of +12V...

You have to remember that this is a 'weird' series-parallel circuit, just like our 2-speed radiator fans... When in DRL mode, the LCM gives one hi-beam positive, and it finds ground through the other hi-beam, making the half-power series-circuit I was talking about earlier - the same way our 2 cooling fans change from low to high speed.

When it's dark outside, the LCM grounds that headlight, and provides both bulbs with +12V through their own wires, creating a parallel circuit...

I see says the blind man....2 12 volt loads on a Series circuit will result in each load having a voltage drop of 6 volts (DRL's), and when creating the extra leg, it now becomes parallel allowing both bulbs to have 12 volts, hence high beams! Thx for clarifying that. Now I look at it and can see it.

I had electronics (automotive) in college, guess you had to refresh me!

ummm......

did you guys not see my last post? idk why youre talking about about park or neutral or anything of that matter.
the area of concern is behind the drivers side headlight.
im not pulling this out of my ass go to lightsout.org.

here is what i am telling you i did over 2 years ago EXACTLY copied and pasted from that site:

1997 Buick Park Avenue (confirmed for 2001 also)
This procedure describes how to deactivate the DRL's on a 1997 Buick Park Avenue by duplicating the factory RPO T62 (no DRL) wiring configuration option, and is probably applicable to most GM cars 1997-present that use high-beam DRL's along with an automatic headlamp system. The only side effects are that the security system and perimeter lighting will no longer be able to flash the DRL's, so only the parking lamps will come on when you activate the security system or perimeter lighting. The automatic headlamps at night and the flash-to-pass feature still work normally.

Deactivating the DRL's. To deactivate the DRL's, remove the driver's side headlamp assembly; on my '97 Park Avenue, this was held in place using two thumbscrews atop the assembly, accessible from under the hood (do NOT mess with the aiming screws) and pull the assembly straight forward to pop the rear retaining pin out of its socket in the fender. After it is loose, unplug or twist and remove the turn illuminator lamp (rearmost bulb in the assembly) if necessary so you can pull the assembly out far enough to see what you're doing.

Locate the "ground" wire of the driver's side HIGH beam headlamp (the lamp closest to the car's centerline); on my '97 PA, this wire is black with a white stripe. You can verify that this is the wire you want by unplugging the headlamp connector and verifying that this wire is +12V when the DRL's would be on (DAYTIME, ignition ON, headlamp switch OFF, transmission in D) and that it becomes a chassis ground when the high-beam headlamps are ON (nighttime or headlamp switch ON, with the high beams activated). Cut this wire at a spot several inches from the headlamp connector.

Carefully endcap the end of the cut wire coming from the control module (the chassis wiring harness end, NOT the headlamp assembly end), to prevent shorts. Then splice the headlamp end of the cut ground wire into the ground wire of the low-beam headlamp (solid black on my car; use a multitester to verify that it's a ground). Solder the splice well to prevent loose connections, tape and insulate it, put everything back together, and you're done. The headlamp wiring now duplicates the factory RPO T62 wiring as described in the factory shop manual.

If you want to get fancy, you can ground the high-beam headlamp through a weatherproof 25A SPDT switch under the hood - one of the plastic air box struts is a good place to put it - with one side of the switch going to the lamp control module and the other side going to a chassis ground, and the wire from the headlamp going to the center contact. This allows you to switch the car between the regular and RPO T62 configuration if desired, but don't attempt it unless you know what you're doing. Suitable weatherproof switches are available from West Marine or other boat stores.

Why this works. When operating the regular high beam headlamps (not DRL's), the Lamp Control Module (LCM) feeds +12VDC to both headlamps separately; the passenger side headlamp grounds through a nearby chassis ground, and the left driver side headlamp grounds through the LCM itself since it has no local chassis ground. In this mode, the high beam headlamps are operating in parallel.

When the headlamps are off and the DRL's are triggered, the LCM feeds +12VDC to the "ground" wire of the driver's side high-beam headlamp, and the current flows in "reverse" through the driver's side headlamp and grounds through the passenger side headlamp. In this mode, the high beam headlamps are operating in series, decreasing the current (and light output) somewhat.

On cars equipped with the RPO T62 (no DRL) option, the driver's side headlamp is grounded to a local chassis ground instead of through the LCM, and the DRL wire from the LCM is either deleted or endcapped. The above procedure duplicates this configuration.

Yes, we saw it. But my method has no side effects (such as the loss of the DRL perimeter lighting,) doesn't require any soldering, and the headlights in the Riviera are a lot more of a pain to mess with than the ones in the LeSabre/PA...

Come to think of it, if someone also wanted to mess with the Twilight sensor wires, he could do it at this same connector instead of pulling the defroster grill.

my method also could have no side effects, the bottom of the last post states that what i did can be also done with a switch.
so have the switch off at night (no DRLs anyway, and when you notice your perimeter lighting), and then in the day flip the switch for no DRLs and its not like you can see your lighting all that great anyway.
if it makes a difference, it doesnt disable ALL perimeter lighting. all of my parking lights and tails light up when unlocking/locking with the key fob, just no DRLs.

Tyler, if you noticed my post a few back, I agreed with you, stating the same thing that you have done. Eldo was just helping me understand the entire circuit regarding to his method. Now I understand it. Thx Eldo! Yes, both methods work. No one is disputing you

I use this method below and worked!!!!!!!!!!!!!!!!!!!!!
Thanks for everyone help SHREK


I agree with you that may work also, but if you look at the schematic, that light green wire is Ign voltage (in Park). When in Park, Ign voltage is supplied to the LCM through that wire. Since there is no ground on the circuit in Park, the DRL's cannot come on. When shifted out of Park, the module "sees" the voltage disappear and grounds the dark blue wire to turn on the DRL's.
Being that the dark blue wire between the left high beam and the LCM is only a "ground" signal, grounding that wire at the bulb to chassis will disable the DRL function and still allow the high beams to work.

I just think it's easier.

Both ways will work, and both will still allow full Twilight Sentinel operation.

Abaddon wrote:

Tyler, if you noticed my post a few back, I agreed with you, stating the same thing that you have done. Eldo was just helping me understand the entire circuit regarding to his method. Now I understand it. Thx Eldo! Yes, both methods work. No one is disputing you

i know nobody was hating on me i just didnt know if you guys saw what i posted, no hard feelings as long as everything works out

shrek wrote:

I use this method below and worked!!!!!!!!!!!!!!!!!!!!!
Thanks for everyone help SHREK

good to hear!
did you do what i posted or what eldo was talking about im confused as to what method you used.

97 parkave I did what you posted abour the twilight sentinel cutting and splice the 2 wire together...worked great..

and abaddon i did what you post about disableing the drl

Thanks again to every one for helping


Shrek