Fog light relay?

[Phuton19]

I just bought my G8, both fog lights are out, i checked the fuse, still good. I don't know if the standard tester will light up the same on the relay, but it did not. Does anyone know where I can get a replacement relay, if that is the issue. I didn't want to have to buy a set of fog lights to check it. I should clarify, I called Advanced Auto parts and they couldn't even order it. So, I am leaning towards a GM dealer for these now.

[Crazy Paul]

Underhood Fuse Block.
F4 is the fuse for foglamps.
R5 is the relay for foglamps.....Grey square with 4 pins. 20 Amp. GM Part No 92199313.

Underhood Fuses.
Red, 10A, 92199303
Blue, 15A, 92199304
Yellow, 20A, 92199305
Clear, 25A, 92199306
Green,30A, 92199307

[Crazy Paul]

146301463114632

[Phuton19]

When you touch a tester to the relay prongs, will it light up like a fuse does to show its still good?

[Crazy Paul]

Sorry, I have NFI how a relay works.
Find one of R5's neighbours or a spare with the same pins and rating and swap them over to see if R5 is dead.

[Eidolon]

Try what Paul said first. :)

A relay should have four prongs. It's an electrically controlled switch. So the switch portion has power and ground terminals and then the input/output terminals are simply pass-throughs that are connected when power is applied to the switch power and ground terminals. In short, it lets the low-current 12V circuit in your car's dashboard switch on the high-current 12V circuit that powers your foglights.

If you put a tester across the switch power and ground terminals, you should read a non-zero resistance (or get a dim light and possibly the sound of clicking from the relay, if that's how your tester works). If you put it across the input/output terminals, you should read infinite resistance unless you have a way to apply power to the switch terminals to activate the relay and close it.

Here's a good little relay basics page (http://www.lunghd.com/Tech_Articles/Electrical/RelayBasics.htm). Pardon the 1990-esque layout.

Easiest way, though, really is what Paul said.

[Phuton19]

didn't even think to try this, thanks! Thanks Eidolon also for the link, I will have to wade through the 90's awesomeness & check it out haha


Sorry, I have NFI how a relay works.
Find one of R5's neighbours or a spare with the same pins and rating and swap them over to see if R5 is dead.

[MIEngineer]

Could be a freak issue where both bulbs are burned out also...

But swapping relays is the easiest way. Did that all the time on my old Volvo to hunt down electrical gremlins.

[LDM]

I'm sorry if this is a stupid question, but since the G8 is new to you, you aren't trying during the day with the Daytime Running Lights on, are you? The fog lights won't come on if the DRLs are on.

[Phuton19]

that is good info, did not know that, but no, I tried turning on the lights themselves, from auto to on, pushed/pulled the fog light knob thingy, nothing. They should come on if I turn the lights to the ON position, correct? Day or night??


I'm sorry if this is a stupid question, but since the G8 is new to you, you aren't trying during the day with the Daytime Running Lights on, are you? The fog lights won't come on if the DRLs are on.

[LDM]

that is good info, did not know that, but no, I tried turning on the lights themselves, from auto to on, pushed/pulled the fog light knob thingy, nothing. They should come on if I turn the lights to the ON position, correct? Day or night??

Correct; with the switch turned to on (not auto) with the knob pulled out, the lights should come on, day or night.

[Phuton19]

Well, if the relay doesn't work, then it's the fog lights next. is there a place you guys order from for those? since I havent torn into them before, is it a whole assembly or just a bulb that comes out of it? Thanks for the responses, awesome.

[Napalm]

Fogs don't turn on unless the the parking lamp or headlamp relays are pulled in first. IIRC, from looking at the schematic.

They are not independent.

Also did you consider putting a volt meter to the plugs only? IE unplug the socket, pull the bulb, turn on lights (as mentioned before) and then volt meter the harness. should get atleast 11 volts.

Failing that the bulbs should be easy to find at any store. OH are you headlamps working correctly?

[Eidolon]

Fogs don't turn on unless the the parking lamp or headlamp relays are pulled in first. IIRC, from looking at the schematic.
They're independent in the circuitry, but they're programmed up to be dependent in the BCM.

[LDM]

Here's the schematics for the fog lights:

http://i843.photobucket.com/albums/zz352/lenmartin23/G8/Diagrams/156525223.gif

They're completely independent from the headlights and park lights, other than in the BCM logic.

[LDM]

They're independent in the circuitry, but they're programmed up to be dependent in the BCM.

Ah, you posted the same thing while I was uploading the drawing. LOL

[Eidolon]

Ah, you posted the same thing while I was uploading the drawing. LOL Yeah, but you got the drawing, so I tip my hat to you. :cool2:

[Phuton19]

I can't see any drawings, but that may be my work computer's settings blocking pics dang it. I will have to wait until I get home probably. thanks for the help. I should call the dealer I got it from and make them fix this, but I dont want to drive 100 miles for them to do it haha

[Napalm]

if all you need is the relay - I'm sure you can order one on the internet. Probably GM parts House.

Because without calling, I doubt you dealer has one. No dealer in my town stocks GM specific parts. Course they might be the same on the camaro or CTS.

If you just need bulbs - then I would think either an autozone or oriely's would have them. But it is an odd bulb.

[Phuton19]

Ended up ordering a relay from a dealer across the state. autoparts stores didn't have it, couldn't order it. 1st dealer was goin to order it from Michigan, but called me back and said his manager needed an order of at least 5 :uhm: So, got it from another dealer, just took a lot of time.

[Phuton19]

So, after trying the relay, still nothing, new fog light bulbs, nothing. What else could it be? the switch itself or wiring issue from the lights? I may drop by a gm place and have them look at it just to give me an idea.

[GXP25]

I had a similar issue. My fog lights worked and then stopped working at one point.

I performed the relay and fuse swap diagnosis to no avail. I also swapped out the side market bulbs (in the side of the bumper, not the headlamp assembly) and fog bulbs. Still no fix. The be clear, the fog light switch, once pulled out in the dash, still works as the fogs lights are indicated as being on on the cluster.

I got help by reading GOPHERIT's post on the other board as it relates to connector X108. This connector is located on the passenger side below the passenger side headlamp housing on a G8. It turns out that the plug was loose and since it's fighting gravity, dealing with going over bumps and whatnot, it got loose. I cannot seem to see if the connector has a TPA (Terminal Position Assurance) connected to it. Or even if it has a provision for one.

#21 in the following image:

http://ls1tech.com/forums/attachments/conversions-hybrids/488323d1424076640-g8-gt-6-0-6l80e-swap-into-72-chevelle-connector-locations.jpg
http://ls1tech.com/forums/conversions-hybrids/1769667-g8-gt-6-0-6l80e-swap-into-72-chevelle-2.html#post18669271

[Dictatorsaurus]

I had a similar issue. My fog lights worked and then stopped working at one point.

I performed the relay and fuse swap diagnosis to no avail. I also swapped out the side market bulbs (in the side of the bumper, not the headlamp assembly) and fog bulbs. Still no fix. The be clear, the fog light switch, once pulled out in the dash, still works as the fogs lights are indicated as being on on the cluster.

I got help by reading GOPHERIT's post on the other board as it relates to connector X108. This connector is located on the passenger side below the passenger side headlamp housing on a G8. It turns out that the plug was loose and since it's fighting gravity, dealing with going over bumps and whatnot, it got loose. I cannot seem to see if the connector has a TPA (Terminal Position Assurance) connected to it. Or even if it has a provision for one.

#21 in the following image:

http://ls1tech.com/forums/attachments/conversions-hybrids/488323d1424076640-g8-gt-6-0-6l80e-swap-into-72-chevelle-connector-locations.jpg
http://ls1tech.com/forums/conversions-hybrids/1769667-g8-gt-6-0-6l80e-swap-into-72-chevelle-2.html#post18669271

Did you need to remove the headlight housing to access the plug?

[BuildItYourSelf]

You can get to the plug from the inner fender, wing tray or pop the passenger fog bezel.
You have to remove the bumper cover to remove the headlights BTW.
Actually on a gt front you may get to it best from the lower grill bezel if it one piece. I'm not got on the gt.
I would do the inner fender. Probably easiest and it's most likely the problem. Grease it up.

[Dictatorsaurus]

You can get to the plug from the inner fender, wing tray or pop the passenger fog bezel.
You have to remove the bumper cover to remove the headlights BTW.
Actually on a gt front you may get to it best from the lower grill bezel if it one piece. I'm not got on the gt.
I would do the inner fender. Probably easiest and it's most likely the problem. Grease it up.


I checked that harness and it was in place and not dangling. I removed it and reconnected and still no fog lights.

So far I've checked the fuse, the bulb filament looks intact and the dash fog indicator comes on.

What else could it be?

[Dictatorsaurus]

EDIT:

I rechecked the harness behind the bumper and it was loose. The tiny retaining notch tab was worn off so I used a zip tie to secure the harness. All good now. Thanks!