Okay, I've asked similar questions before and some of you have been kind enough to respond. I think I'm getting closer to solving my foglights-on-in-gear problem. The question now is this:

I know the fogs come on with the key on. What do your DRLs do when the fogs are on? Do they shut off (you have to put the car in gear, in daylight, with the fogs on)? The manual says that "any event that calls for headlamps cancels the DRLs". Turning the fogs on calls for the parking/tail lamps and issues a command to the IPC to illuminate the "LIGHTS ON" message, but is that a call for headlamps (and would that kill the DRLs?)?

I'm trying to figure out of my DRLs are being backfed by the foglamp circuit. If your DRLs stay illuminated with the fogs (again, daylight only) then I can eliminate one possibility.

In a nutshell, I think the DIM outputs for the DRLs and the foglamps are spliced together somewhere. Everything else from the switch, through the IPM to the DIM seems to be operating correctly. The answer to this DRL behavior question will help me confirm or dismiss that theory.

As an aside, when the daylight sensor thinks it's dark out it calls for headlamps thus killing the DRLs. If you have the twilight off you hit the foglight button and the fogs and parking lamps will come on without the headlamps. I think this is a cool look, but I think you can only do it when the sensor thinks it's dark out.

TIA,
Jim

I pulled the fuse for my DRL's.. I hated them. I can run my fogs only now by turning off the daylight sentinal. It is a much better look.

My problem is that I use Sylvania Silverstar bulbs in both headlights and fog lamps, but I seem to blow a 20 dollar fog lamp bulb about every other month.


Oh, and to answer some of your questions... The fogs should not affect the DRL's at all. If you put the fogs on during daylight it does not shut off the DRL's.

The fogs will turn on the parking lights though. I wish I could figure out how to wire it so just the fogs turn on without the parking markers.

I pulled the fuse for my DRL's.. I hated them. I can run my fogs only now by turning off the daylight sentinal. It is a much better look.

My problem is that I use Sylvania Silverstar bulbs in both headlights and fog lamps, but I seem to blow a 20 dollar fog lamp bulb about every other month.


Oh, and to answer some of your questions... The fogs should not affect the DRL's at all. If you put the fogs on during daylight it does not shut off the DRL's.

The fogs will turn on the parking lights though. I wish I could figure out how to wire it so just the fogs turn on without the parking markers.


Thanks for the info. I hate the DRLs too - maybe I'll just pull the fuse. I have Silverstars in the lows and fogs and they are expensive to replace. Actually, it's good that the DRLs stay on with the fogs - that means mine's behaving properly. It confirms my theory that the DRL and foglight ground wires are wrongly connected to each other somehow.

My fogs come one when I take the car out of park (like the DRLs). The DRL and fog relays are physically next to each other in the fusebox, and both have an output wire out of the DIM. The output wire on the DIM closes the coil on their respective relay to activate the DRLs or Fogs. The DIM knows to do this from the IPM. The IPM gets its info from the foglight switch (for the fogs) or the sunlight sensor (DRLs). They are separate circuits but mine are connected somehow. I think it's either at the DIM or at the fusebox.

As far as killing your parking lights, I'm not sure how you can do that. The feeds out of the DIM for exterior lighting are all separate - low beam, high beam and parking (which includes tail). If you clip the parking lead, though, you'll lose the parking lights under all other non-manual functions (like lock/unlock confirm, twilight, etc.). They'd only work with the switch in the dash. Also, since the DIM decides to turn on the parking lights in response to serial data, there's no easy way to stop that data for some situations but not others.

What you can do is 'break' yours the way mine is broken. If you connect the lead for the DRLs out of the DIM to the foglight lead you'd get fogs when the car is in gear w/out any parking lights. Even if you pull the DRL fuse this still works. If you push the fogs button on the dash, you'll get parking lights with the fogs.

Jim

I don't think i am going to mess with it. I am happy with it, especially since pulling the DRL fuse.

Yes, something is definitely up with your fogs and DRL's. The fogs should stay on wether or not the car is in park or drive. But if this is the only issue you have after rebuilding your entire car, I would say you are doing extremely well!

As for the Silverstar fog bulbs, I think either vibration or moisture is killing them. No way I should be blowing one a month.

I think I am going to move to HID's but I don't know if there is an HID kit for the fogs. I am looking into the possibility of retrofitting my DTS with the 06 DTS projector beams, I started a thread on it. But I don't know if it will be more trouble than its worth. I am gonna rent an 06 and play a lil doctor to see what it would take. You gotta love the rentals. :sneaky:

what up fellas, I think your lights are working right turboJ. I also hate my DRL's and always thought they were working improperly also. ok here it is.... when its DAYTIME: the headlight are on regardless if there switched on or not and regarless if my foglights are on or not. now at NIGHT: with the headlight switch off and fogLights off the headlights are on, but if i turn 'on' the foglights the headlights turn 'off' unless you turn the switch on, then both are on, with me? yea i also got rid of the ugly yellow stock lights and upgraded to the blue-ish tinted HID headlights and foglights, and yes they blow every other month or so, actually 1 foglight just blew out yesterday and i dred changing it since you must go underneith the car remove all the clips and that pannel b4 you can get to the light , just another headach ya know. I have a question though for Mr. HITMONEY , i want to pull the fuse for the drl's also no does that affect any other components or will it just allow me to put the lights on when I want them on??

" NYinfamous "

Yes, something is definitely up with your fogs and DRL's. The fogs should stay on wether or not the car is in park or drive. But if this is the only issue you have after rebuilding your entire car, I would say you are doing extremely well!

As for the Silverstar fog bulbs, I think either vibration or moisture is killing them. No way I should be blowing one a month.

I think I am going to move to HID's but I don't know if there is an HID kit for the fogs. I am looking into the possibility of retrofitting my DTS with the 06 DTS projector beams, I started a thread on it. But I don't know if it will be more trouble than its worth. I am gonna rent an 06 and play a lil doctor to see what it would take. You gotta love the rentals. :sneaky:

I think the car was like that before the flood. This is not an accident - someone had to have tied those circuits together. The only real problem with the car is that the heated seats don't work (elements are no good after the flood).

I blow a driver's side foglight every other month, too. The passenger side is fine.

Looks to me like the 2006 is the same from the windshield to the rear glass. I think an entire nose would graft onto a pre-'06 (fenders, hood, bumper cover, lights and grille).

Jim

what up fellas, I think your lights are working right turboJ. I also hate my DRL's and always thought they were working improperly also. ok here it is.... when its DAYTIME: the headlight are on regardless if there switched on or not and regarless if my foglights are on or not. now at NIGHT: with the headlight switch off and fogLights off the headlights are on, but if i turn 'on' the foglights the headlights turn 'off' unless you turn the switch on, then both are on, with me? yea i also got rid of the ugly yellow stock lights and upgraded to the blue-ish tinted HID headlights and foglights, and yes they blow every other month or so, actually 1 foglight just blew out yesterday and i dred changing it since you must go underneith the car remove all the clips and that pannel b4 you can get to the light , just another headach ya know. I have a question though for Mr. HITMONEY , i want to pull the fuse for the drl's also no does that affect any other components or will it just allow me to put the lights on when I want them on??

" NYinfamous "

Pulling the DRL fuse does nothing but disable the DRL's. It will not affect anything else.

I think you are confusing the DRL's with the headlights. The DRL's (Daytime Running Lights) are your regular beam headlights running at a lower voltage (so I've been told).

Your headlights are either controlled manually or by the Daylight Sentinal which will automaticly turn off your DRL's and turn on your headlights once the daylight sensor on the dash determines that it is time for headlights. This sensor can go bad which would leave your headlights on all the time. I was told by a Caddy Tech that when the sensor goes bad it will just leave the headlights on all the time rather than the DRL's as a safety feature.

The fog lights are manual use only and run entirely independent from the headlights and DRL's. The fogs are turned on by the switch on the dash. If left on and you turn the car off, the will come back on the next time you turn the ignition on. They only go off if you manualy turn them off, and only go on if you manualy turn them on. It does not matter wether the car is in park, or drive, if the switch is pushed they should come on.

I think the car was like that before the flood. This is not an accident - someone had to have tied those circuits together. The only real problem with the car is that the heated seats don't work (elements are no good after the flood).

I blow a driver's side foglight every other month, too. The passenger side is fine.

Looks to me like the 2006 is the same from the windshield to the rear glass. I think an entire nose would graft onto a pre-'06 (fenders, hood, bumper cover, lights and grille).

Jim

Graft the whole front end!!! WOW.. you do really think BIG! LOL

All I want is the projector beam headlights.

Graft the whole front end!!! WOW.. you do really think BIG! LOL

All I want is the projector beam headlights.

I can see it now, I rent a new 06 DTS, but when I return it it has an 02 front end!!! :sneaky:

Easy enough to disable DRL if your year is the same as my '04.

Remove left headlamp assembly. There is a high wattage ceramic resistor mounted on the radiator support panel. Remove the connector from that resistor. Job finished.

I took it one step farther and jumpered the proper pin on that connector as a power feed to the fogs. I like DRLs and the fogs are just fine by me. I have a note somewhere on this computer if anyone wants the wire colors and procedure. I did use a diode to avoid any unintended consequences.

Don't you think it is easier to just pull the 15amp fuse?

Graft the whole front end!!! WOW.. you do really think BIG! LOL

All I want is the projector beam headlights.

I know, I was just thinking about how to update the overall look. The '06 DTS headlights wouldn't fit without changing the fenders, grille and bumper cover (unless you do some creative body work to the pre-06 nose). I'll have access to '06 DTS wrecks as time goes on. Maybe I'll update my '01.

Jim

I took it one step farther and jumpered the proper pin on that connector as a power feed to the fogs.

That's the first thing I checked on my car. I figured someone tapped into that circuit at the resistor because it's easy to get at. The fogs are behaving as DRLs. But if you pull the DRL fuse my fogs stay on, so it has to be jumped to the DRL ground at the coil side of the relay relay. The fuse interrupts the switched side of the relay, so if the fogs were tapped into the resistor circuit on the DRLs they'd go out when you pull the DRL fuse.

This conversation is helping me to get to the bottom of it - thanks all.

Jim

what up fellas, I think your lights are working right turboJ. I also hate my DRL's and always thought they were working improperly also. ok here it is.... when its DAYTIME: the headlight are on regardless if there switched on or not and regarless if my foglights are on or not. now at NIGHT: with the headlight switch off and fogLights off the headlights are on, but if i turn 'on' the foglights the headlights turn 'off' unless you turn the switch on, then both are on, with me?

This is what had me confused initially. I thought that because the DRLs were off at night when the fogs were on that the fog circuit canceled the DRLs. But HITMONEY is right. There's no correlation between the fogs and the DRLs OR the fogs and the headlights. The only correlation is between the DRLs and the headlights. A call for headlights cancels the DRLs, which is why if you shut off the Twilight you can put just the fogs and parking lights on - the sun sensor has called for the headlights and canceled the DRLs but you've manually shut them off with the Twilight.

My fogs come on ONLY when I take the car out of park so they're definitely not working right. I can't shut them off either, unless I put the car in park.

Another thing that had me confused was the 'LIGHTS ON' message. I thought it was tied to the headlights. It's not. It's tied to the parking lights, which is why you get "LIGHTS ON" when you turn on the fogs. I thought the fact that this "LIGHTS ON" indicator was lit meant that the headlights were on and thus the DRLs were canceled. That's not the case. LIGHTS ON illuminates when the DRLs are still lit in when you have the fogs on. This is what had me thinking my DRLs were being backfed by incorrect fog light wiring.

Anyhow, I think the problem is in the wiring from the DIM to the relays or something at the fusebox itself. I think I'm very close to figuring this out.

Jim

On a side note... I went to the auto parts store and bought a new Silverstar 893 fog lamp for my passenger side. Got home jacked the car up replaced the lamp, put on the fogs just to see that I now have a blown Drivers side fog.:bomb:

Back to the store to buy yet another 24 dollar bulb.

What is the dealeo with these things!!!!

:wtf: :rant2:

What is the dealeo with these things!!!!

:wtf: :rant2:

I dunno but I'm glad it's not just me. But for some reason only my driver's side blows.

Jim

It sounds really simple but it took a while to narrow down the possibilities.....

Only gawd knows why, but someone had the C3 connector at the Dash Integration Module (DIM) apart at some point. I know it wasn't me - the fogs have been doing this since they dumped the car off the flatbed. Anyhow, the DIM sends the ground to the relays to close the DRL and fog circuits. Position A4 is the DRLs and position A7 is the fogs. I thought maybe someone had spliced the A7 wire to the A4 wire thus turning the fogs on when the car is in gear (when it calls for DRLs). But, there was no wire in A7. Hmmmm. The green/white fog wire was in position B6, which is for Export or V4U (limo conversion) "standing lamp". Standing lamps are only supposed to operate in park (which is the opposite of how my fogs were behaving), but who knows what that position in the connector does with the domestic DIM. I moved the green/white wire to position A7 on the C3 connector and BAM! Fogs work like they should.

Thanks all!

Jim

Glad you figured it out!

You have become a real Deville expert!

Glad you figured it out!

You have become a real Deville expert!

I guess - talk about learning things the hard way. Knowing the ownership history of the car (it was a corporate limo), only the dealer would have done that. It was either an accident or someone wanted the fogs to come on with the DRLs. Either way it bugged me. I'm glad it's 'fixed'.

Jim

I also ordered a normally closed relay today (they're very hard to find). I'm going to use the foglight ground out of the DIM to power the relay and open the circuit for the DRLs. That way the DRLs will go out when I turn on the fogs. I'm cool with the DRLs at all other times, but I prefer to have them off when I turn on the fogs.

Jim

So I got around to installing the relay to break the DRL circuit. I got the coil voltage from the accessory feed into the DIM and the ground for the coil from the fog light relay feed. This way when the foglight relay feed goes to ground (when I turn on the fogs) it interrupts the DRL circuit. So in theory the headlights should go off when I turn on the fogs.

But no. Something's f'd up now. Headlights come on with the key now. So I took the relay out. Same thing. Fogs work like they should, but now the headlights are on all the time. The car doesn't think it's dark out though - dash doesn't dim and I don't get the HEADLAMPS SUGGESTED message when I shut off the Twilight Sentinel. And when I leave the Twighlight Sentinel on and shut the key off the headlights go out (if it thought it was dark out it would leave the lights on for a set amount of time). The headlights go out when I shut off the Twighlight Sentinel though. I don't know what to think now. This is where the old adage "if it ain't broke don't fix it" applies. Now I've created another mystery for myself.

Jim

Okay - it wasn't f'd up. There's just some middle ground between total darkness and dusk with regard to how the light sensor works. It did it again today. It was getting dark out, but not not dark enough for the car to light up the high beams and back up lights when I unlocked the doors. When I started the car the lights were on. It's been behaving fine all week so I think I panicked for nothing.

I got a new relay yesterday that looks like it's more suited for the task. I'll pop it in tomorrow and see what happens.

Jim

EUREKA! It works. If anyone is interested in doing it yourself, here's how it goes.

First you need a NORMALLY CLOSED relay. These are hard to find. The universal ones in the auto parts stores are normally open because they're made for auxiliiary lighting. They do have 5 lugs like a normally closed relay, but both of the '87' lugs are normally open. The reason there are two is so you can easily wire up 2 lights.

I got a normally closed relay from www.newarkinone.com. It's an OMRON part number G8JN-1C7T-DC12. It was $5.33 plus $5.00 shipping/handling.

All your work is done on the C3 (pink) connector on the Dash Integration Module. It's easy to get at by removing the knee bolster and dash trim panel on the passenger side. The pins are arranged A1 through A12 on the top and B1 through B12 on the bottom (the top of the connector is where the clip is).

Lugs #30 and #87A on the relay complete the normally closed circuit. Position A4 (light green/black wire) on the DIM's C3 connector provides ground to the DRL circuit. You cut this wire and connect one end to the #30 terminal and one end to the #87A terminal on the relay. By doing so the DRLs operate as they normally would, until the relay is activated by turning on the fogs.

To activate the relay when you turn on the fogs, you need power and ground. Power comes from position A2 (brown wire) on the DIM connector - tap into this circuit and run it to one side of the relay's coil (terminal 85 or 86). The ground comes from position A7 (dark green/white wire) on the DIM connector. This wire goes to ground when you turn on the fogs. Tap into it and run it to the other relay coil terminal.

It sounds like a lot of work but it really isn't. Now, when you turn on the foglights the DRLs go out which IMO is a cool look.

When it's dark out, the DRLs automatically get shut off by the sun load sensor. If you want to run with just the fogs on at night (though I wouldn't recommend it) you just shut off the twilight sentinel.

Jim

Hello...

Great Job!

Thanks for the directions...sometimes I'm not very good at reading schematics...but I am good at following directions!

I haven't researched this, but do you think it would work with a 2000 STS w/DRL+Fog?
I realize the actual connections might be different, but in theory it should work-
...(a relay is a relay).

Post back your opinion.
Thanks!

Hello...
Great Job!
Thanks for the directions...sometimes I'm not very good at reading schematics...but I am good at following directions!
I haven't researched this, but do you think it would work with a 2000 STS w/DRL+Fog?
I realize the actual connections might be different, but in theory it should work-
...(a relay is a relay).
Post back your opinion.
Thanks!

I would venture to guess that the STS wiring is the same, I bet it uses the same DIM too. The factory service manual will have a 'connector end view' with a list of pin positions and wire colors.

Jim