Fog lamp went out

snide · 11-09-02, 05:44 PM

Last year I replaced the stock fog lamps with the PIAA 1100x lamps. These fog lamps rock!

Anyway, a couple of weeks ago, the lamp on the driver's side went out, just before inspection time.

I ordered a replacement bulb and put it in today. However, the fog lamp still isn't working.

Any thoughts, suggestions?

Thanks.

c4c5specialist · 11-09-02, 05:59 PM

Hi there,
I would suggest that you switch the left one for the right one, and see if it works correctly.
It is possible that you got a bad one right out of the box.
This I have seen a few times.
Other than that, there would only be a short circuit in that part of the system, that is not allowing power to be given to the bulb, or not allowing ground to be given to the bulb.
Sorry, could be of more help, and please keep us posted as to your solution, c4c5

snide · 11-10-02, 11:05 AM

Hi c4c5,

I just switched the fog lamps around and the new bulb is working fine. So it looks as if there is an electrical problem somewhere. I checked the fuse box under the hood and the fog lamp fuses look fine.

Any other suggestions?

Thanks.

c4c5specialist · 11-11-02, 06:18 PM

HI there,
Well, the purple wire is your 12 volts into the light bulb, on both sides.
Have you had anything done to the front end of the vehicle????
Bodywork, or paint, or anything else????
The wire will run from the underhood electrical center, to the right front of the vehicle, and then across the front bumper assembly, to the left hand side.
The wires are separate from the fuse panel, to the light bulbs.
Let us know how you make out, c4c5

snide · 11-11-02, 07:44 PM

Nope, nothing done to the front end. One day the light was working, the next day it wasn't.

I found the wire harness but did not trace it back as far as the fusebox. I'll pickup a multimeter and test the wiring sometime this week. I'll keep you posted.

Thanks.

snide · 11-16-02, 03:31 PM

Ok, the wiring to the fog lamp connector tests out at 12 volts. When the lamp is plugged into the connector, I can't get a reading on the lamp side of the plug.

The strange part is that this lamp did work on the right side last week when I did the swap test.

I'm going to put on new connectors to see if that does something for me.

c4c5specialist · 11-16-02, 08:21 PM

Hi there,
I have seen a few with higher demand fog lamps burn out connectors, in the socket themselves.
Does anything look melted or burnt???
Please keep us posted, c4c5

snide · 11-16-02, 09:09 PM

The connectors looked fine. Even if the existing connectors were melted, that still doesn't explain why the same lamp worked on the right side but is not working on the left side. Also, I put on all new connectors and still no worky.

FLIR_man · 11-20-02, 07:14 AM

Sounds like the source power wire or ground wire is barely making contact at some point. A voltmeter does not draw any current so you can get a reading, however once there is a load (the bulb) the resistance in the circuit is high enough to not allow current flow. The manual should have locations of any connectors or connections between the power or ground source. It could also be in the switch if it does not control a relay. If the switch controls a relay then that is most likely the culprit. If I had a wiring diagram in front of me I could tell you for sure. Anyway it is a poor connection within the circuit.

After I get home tonight from the shop I will look at a diagram. Last night my 2000 C5 steering column locked up and the engine quit "after" I pulled out of my parking spot.

FLIR_man · 11-21-02, 07:11 AM

Hi Again,

My first suggestion is to jumper a wire from the purple wire of the left fog lamp to the purple wire of the right fog lamp. If both fog lamps come on then you know it’s the power connection that’s bad. If that does not work try jumpering the ground wires next. If you still do not have a light your new connector is bad.

I looked over the schematics and there are two possibilities for poor connections. There is a splice pack (sp100) located at the RH headlight opening. This is where the ground is terminated for both fog lamps. It is possible but not probable that you have a poor connection here. Tug each wire in the splice and see if one is barely hanging on.

The other connection is at the Under Hood Electrical Center. There are three connectors that the Under Hood Electrical Center plugs into. You could remove the Electrical center and check for corroded contacts or loose wires in the harness. If you do this use an electrical contact cleaner before reassembling.

Hope this helps. Let me know what you find, and if it still does not work Ill think of something else.

FLIR_Man
(Gary)