Now I'm stumped...
Thread Starter
Instructor
Joined: Jul 2006
Posts: 132
Likes: 2
From: Melbourne FL
Now I'm stumped...
So a while back both my fog lights stopped working for some reason. I just checked the fuse and no problem there. I went ahead and bought replacement bulbs even though the originals didn't appear to be blown on visual inspection. Re-connected the battery and still nothing. I reset all the codes on the computer and tried the lights, but still nothing. I'm at a loss at this point as to where my point of failure is.
Anyone got a clue?? I'm going
without that extra light!!! I never thought they did that much until you start driving without them for a while.
Is it possible that the relay has gone bad? If so, how do I get it out because it doesn't seem to want to budge.
Thanks,
Trevor
Anyone got a clue?? I'm going
without that extra light!!! I never thought they did that much until you start driving without them for a while.Is it possible that the relay has gone bad? If so, how do I get it out because it doesn't seem to want to budge.
Thanks,
Trevor
Le Mans Master
Joined: Feb 2003
Posts: 6,683
Likes: 144
From: Memphis Tennessee
Hummm.....
I would get a reliable volt/ohm meter and check voltage at the sockets, resistance across the fuse you think is good, voltage at the fuse slot and then......(hopefully not needed) pull the interior panel off and check the operation of the switch using the meter.
Good Luck
I would get a reliable volt/ohm meter and check voltage at the sockets, resistance across the fuse you think is good, voltage at the fuse slot and then......(hopefully not needed) pull the interior panel off and check the operation of the switch using the meter.
Good Luck
Thread Starter
Instructor
Joined: Jul 2006
Posts: 132
Likes: 2
From: Melbourne FL
The light toggles off/on at the switch inside so I don't think that's the problem. I guess I'll have to get the voltmeter out and try to track down my point of failure.
Anyone have any other idea/suggestions?
T
Anyone have any other idea/suggestions?
T
Safety Car
Joined: Jul 2004
Posts: 3,904
Likes: 29
From: Vancouver Washington
Originally Posted by FletcherT76
The light toggles off/on at the switch inside so I don't think that's the problem. I guess I'll have to get the voltmeter out and try to track down my point of failure.
Anyone have any other idea/suggestions?
T
Anyone have any other idea/suggestions?
T
Team Owner
Joined: Jul 2006
Posts: 22,164
Likes: 4,171
From: Kannapolis NC
Just a thought, don't they only come on when lights are on dim? If that's so, there must be a contact that turns them off when switching to bright. Maybe the multi-function switch or a relay between. I don't have a service manual, so I can't look it up for you.
Thread Starter
Instructor
Joined: Jul 2006
Posts: 132
Likes: 2
From: Melbourne FL
Originally Posted by Last C5
Isn't there an electrical connection in front of the front fenderwells that is in weather and is sometimes the culprit?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Racer
Joined: Nov 2005
Posts: 339
Likes: 0
From: Davenport IA
The relay went out on my '00 coupe. Its a standard relay in the underhood relay box. They are pretty tough to pop out, but with some persuasion it will come out. I would check that first, much easier then tearing into other wiring...
Jay
Jay
Le Mans Master
Joined: Nov 2002
Posts: 7,179
Likes: 2
From: Charlotte, NC
try swaping the relay with another one and see if they work.... thats a real quick step... otherwise voltmeter or test light check power ground at the socket and work your way back to the source to isolate the problem.
good luck
-=Rick
good luck
-=Rick
Thread Starter
Instructor
Joined: Jul 2006
Posts: 132
Likes: 2
From: Melbourne FL
Thanks guys! Is there a trick to removing the relay? I gave it a pretty good pull when I was first trying to diagnose the problem but it didn't want to give. I even tried to gently use a pair of plyers to get a better grip but still didn't seem like it was coming out, so I gave up not wanting to break it. I'm guessing it goes in just like a fuse - a couple prongs jammed in there??
I just remembered that when I had the hood up and pushed the fog light inside I could here a clicking sound from the fuse area. Is this indicative of a bad relay, or just normal functionality?
T
I just remembered that when I had the hood up and pushed the fog light inside I could here a clicking sound from the fuse area. Is this indicative of a bad relay, or just normal functionality?
T
Thread Starter
Instructor
Joined: Jul 2006
Posts: 132
Likes: 2
From: Melbourne FL
Still stumped...
Well my fog's still aren't working. I replaced both lights and all fuses just to be doubly sure that everything was correct there. I even stopped at the dealership yesterday to get some assistance on it. 
We pulled the relay out from the fuse box and put in a new one as a test; but the lights still don't work. I can here it click when I turn the fog light's on/off from the interior switch so I know there is power going to the fuse box.
I guess my question is how do I track down the point of failure from here? Anyone have a wiring diagram that would show where the wires go from the fuse box to the fog lights? What about the ground point - anyone know where that is so I could check there??
All other lights function properly, no codes in the DIC, and no other issues with the car besides this one thing.
Hope someone can help.
Trevor
We pulled the relay out from the fuse box and put in a new one as a test; but the lights still don't work. I can here it click when I turn the fog light's on/off from the interior switch so I know there is power going to the fuse box.I guess my question is how do I track down the point of failure from here? Anyone have a wiring diagram that would show where the wires go from the fuse box to the fog lights? What about the ground point - anyone know where that is so I could check there??
All other lights function properly, no codes in the DIC, and no other issues with the car besides this one thing.
Hope someone can help.
Trevor
Drifting
Joined: Nov 2003
Posts: 1,894
Likes: 6
From: Sahuarita AZ
How do your grounds (studs on the frame) near the hood struts look? You might try spraying some contact cleaner on them as I believe that's where the fog lights ground to.
Someone with the GM Service Manual DVD should be able to post a wiring diagram for your.
Someone with the GM Service Manual DVD should be able to post a wiring diagram for your.
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
I don't have fog lamps, but the 2001 Service Manual wiring diagram shows:
Lamps are grounded at G102
They are powered by Purple wires (black is ground) that are powered directly off the FL Relay (#39) located in the Underhood fuse block.
Relay 39 is protected by fuse #6 (10 Amp) also in the underhood fuse block.
Power from the fuse also feeds the Fog Lamp indicator located with the fog lamp switch on the dashboard.
Weird as this may seem, the power source for the dashboard switch itself is from Fuse 32 (15 Amp) - Labeled Fuel Tank Door in the I/P fuse block. The power comes from that fuse, through the switch, and to the BCM.
HTH
Lamps are grounded at G102
They are powered by Purple wires (black is ground) that are powered directly off the FL Relay (#39) located in the Underhood fuse block.
Relay 39 is protected by fuse #6 (10 Amp) also in the underhood fuse block.
Power from the fuse also feeds the Fog Lamp indicator located with the fog lamp switch on the dashboard.
Weird as this may seem, the power source for the dashboard switch itself is from Fuse 32 (15 Amp) - Labeled Fuel Tank Door in the I/P fuse block. The power comes from that fuse, through the switch, and to the BCM.
HTH
Last edited by BlackZ06; Dec 20, 2006 at 01:49 PM.
Thread Starter
Instructor
Joined: Jul 2006
Posts: 132
Likes: 2
From: Melbourne FL
Thanks for the info BlackZ06. Since I don't have it in front of me, let me see if I can get this straight:
Power flows from the battery > #6 fuse > #39 relay > fog lights via purple wires and grounded at G102. Is that correct?
Also, can you tell me where G102 is located?
Thanks again!
Trevor
Power flows from the battery > #6 fuse > #39 relay > fog lights via purple wires and grounded at G102. Is that correct?
Also, can you tell me where G102 is located?
Thanks again!
Trevor
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Maybe this'll help make it clearer ....
When you push the button to turn ON the fog lamps, that completes a curcuit powered from Fuse 32 to the BCM.
When the BCM sees power on that wire, it closes two other circuits. One curcuit turns on the Fog Lamp Indicator in the dash once relay 39 closes, and the other curcuit sets Relay 39 to ON which then powers up the lamps and the indicator.
Since Relay 39 powers both the Indicator and the lamps, if your FLs aren't coming on, but the indicator light is ... then the problem is either in the relay itself or the wiring from the Fuse Block to the lamps (Purple wires).
I'd test the switch itself (Orange wire is power from Fuse 32 - Orange/Black wire goes to BCM) to see if that's working, check the BCM for DTCs indicating a FL problem, then if the BCM has no codes it is either the relay (39), the fuse (#6) or in the wiring harness from the Fuse Block.
HTH
When you push the button to turn ON the fog lamps, that completes a curcuit powered from Fuse 32 to the BCM.
When the BCM sees power on that wire, it closes two other circuits. One curcuit turns on the Fog Lamp Indicator in the dash once relay 39 closes, and the other curcuit sets Relay 39 to ON which then powers up the lamps and the indicator.
Since Relay 39 powers both the Indicator and the lamps, if your FLs aren't coming on, but the indicator light is ... then the problem is either in the relay itself or the wiring from the Fuse Block to the lamps (Purple wires).
I'd test the switch itself (Orange wire is power from Fuse 32 - Orange/Black wire goes to BCM) to see if that's working, check the BCM for DTCs indicating a FL problem, then if the BCM has no codes it is either the relay (39), the fuse (#6) or in the wiring harness from the Fuse Block.
HTH
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Thanks for the info BlackZ06. Since I don't have it in front of me, let me see if I can get this straight:
Power flows from the battery > #6 fuse > #39 relay > fog lights via purple wires and grounded at G102. Is that correct?
Also, can you tell me where G102 is located?
Thanks again!
Trevor
Power flows from the battery > #6 fuse > #39 relay > fog lights via purple wires and grounded at G102. Is that correct?
Also, can you tell me where G102 is located?
Thanks again!
Trevor
battery > #39 relay > #6 fuse > fog lights.
from #6 fuse to fog lights is purple wire, and then coming off the lamps are BLACK wires that are groundeed at G102. Let me find G102 and I'll post another reply in a couple of minutes
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
G102 is on the top of the passenger side frame rail - in the engine compartment - forward most ground point, should be about even with the front of the wheel well (forward part of the wheel well liner).
Thread Starter
Instructor
Joined: Jul 2006
Posts: 132
Likes: 2
From: Melbourne FL
Thanks for the info again BlackZ06. I'm looking around to see what I can come up with, but in the process found this little oddity on the drivers side. The pictures are drivers side, looking through the fog light housing (previous owner cut out the opening).
What is this connector? It's wires are a part of the grouping that comes over to the drivers side FL and has just been zip tied to the wiring harness:
A closer look:
Then I found this wire just comes out of the plastic sleeve and was just loose behind the body panel - any clue at all what this is!?
What is this connector? It's wires are a part of the grouping that comes over to the drivers side FL and has just been zip tied to the wiring harness:
A closer look:
Then I found this wire just comes out of the plastic sleeve and was just loose behind the body panel - any clue at all what this is!?
