Outdoorvette

Hello..first time user (hold the applause please)....
Question: I recently changed out my factory fog lights with some Auto Zone Sylvania Silverstar 803 ST's. Everything went great and worked fine till one day driving home after work.
Problem: The fog indicator light comes on when the swich is pulled, but the lights now do not light.
I have tried replacing the sylvania's with the factory lights and no luck. Changed fuses and relay with no luck. Checked voltage at the pigtail and it has power.
Any help on this...
Thanking everyone in advance...

phox_mulder

I don't have fog lights, but I remember seeing something about them being disabled if the high beams are on.

I guess it's against some law to have high beams and fog/driving lights on at the same time?

Worth checking, as it is a free fix.
Might even be the high beam switch being stuck semi on.



For future posts, it might help if you fill in your signature with year and model of your truck, at least.
Every year is different and has it's own quirks.

This is done by clicking on the "user cp" button up under the main logo, then "edit profile" then enter info in the signature box, then click submit at the bottom of the page.

My signature, at the bottom of this post, is an example of a very full one


phox

Outdoorvette

Thanks Phox...I corrected my profile per your suggestion. I guess you can chalk it up to being the newbie...
My problem is not related to the high beams. I have no modifications that would allow my fog lights to come on with the high beams, they just don't come on period.
My son and I checked everything again this afternoon to no avail. One thing I did notice is that when I turn on my headlights the backlighting around my headlight switch does not illulimate and I have to tap rather hard on the dash for it to come on. This may or may not be related to my fog light problem. I even pulled the switch out and checked all the connections and no luck....
I am really stumped with this one....
Thanks again for taking the time to help with the profile thing and if you or anyone else can think of a solution let me know...
take care,
Tom

Stamey

Do you know if your headlight switch is getting hot?
Do the new lights draw more current than the stock lights?
I have heard that the headlight switch in some trucks (I forget the TSB number) will burn itself up, and your driving lights not working may be the first sign.
There are also 2, count'em, two fog lamp relays, according to the wiring diagrams in my Haynes manual. No, I don't know where they are located. It's got diagrams but no component locator.
I'm interested in this because I was thinking of changing out mine, especially since the factory driving lights look yellow now that upgraded headlights.

Chris

Outdoorvette

Hey Chris..thanks for the quick response. The current draw is not an issue, the wattage on the replacement lamps were the same as the factory ones. This was one of the first things I checked.
The switch itself does not get hot, but the constant pounding on the dash to get the darn backlighting lit is getting old.
I was not aware of the two relay issue, I only found one, but thanks to your info I will most certainly check around for the second.
It may be the switch going out. Is this something only a dealer can supply? It not, any ideas on getting a new one without hitting the local junk yards.
Thanks again,
Tom

dunerr

Hello.

I just bought my truck and have the same problem. I am an electrical tech and just tracked it down. my truck had extra fog lights added but neither the stock or aftermarket ones would come on.

1. With the lights on low beam and the fog light switch in the on position no power at the harness by the lights.

2. checked the fog light fuse, its ok but it is a 30 amp fuse ? way to big

3. There are two relays in the upper left of the box that control the fog lights. The first one is turned on and of by the high beam and low beams. if you have the high beams on the second one will not pull in.
4 The second relay is also controled by the fog light sw. if its not on it will not turn on.
5 i pulled out the relays and checked the voltages the first one is fine but the second one had no power to be switched on to the fog lights. i jumped power to the relay connection and the lights came on.
6. i tried to get to the bottom side of the fuse box but could not get to it so.

i am planning on doing some custom wiring to fix the problem.

hope this was of some help. i am sure the lights overloaded the stock wiring and fried my connection under the fuse box.

Commatoze

Outdoorvette, when you say you have power at the pigtail, do you mean the connector on the cross-member under the radiator?

dunerr, I lost my factory fogs when I switched out the front bumper. I decided to buy a cheap pair of lights to see if they would last the winter attached to the underside of the front cross member. If they did (so far they have) I'd go with a pair of PIAA's. Problem was, with the light mounted to the frame, I immediately blew the fuse when I attempted to turn the lights on. If I left the lights dangle from their pigtails, no problem. Turns out the stock wiring switches +12V and that the stock lights were isolated from frame ground. The cheapo fogs were grounded to their mounting frames so I'd short +12 directly to ground when I'd try and turn them on. My solution was to RTV the light assembly to the frame and not use any mounting hardware. They're literally glued on and isolated from the frame. The whole point of this long-winded post is to suggest that you remove the aftermarket lights, or let them dangle free of the chassis, check the fuse, and then try turning them on.

Tom

dakar

The back lighting on the '01's (not sure of others) is actually just a single little bulb, with a rather screwy looking back, there are two behind the housing, one grey and the other black, one for backlight and the other for the log light indicator. They release from their homes with about 1/4 turn from a flathead screwdriver. The bulbs are tiny, and the power leads are sorta of wrapped/woven into the little plastic deally to make contact with the pcb on the rear of the housing. Short of ordering them from the dealer I have no idea where to replace them from, can't find them anywhere 'aftermarket'. Same thing on the climate control panel. I gave up looking for replacements, so I'm replacing them with LED's this weekend.

Hired Gun

I have run through the posts, and havent read all. Sorry I get bored real fast. Try your switch. That portion could be burned out. Happened to me on my 99.

Outdoorvette

Thanks for all the info guys..I have been out of town for a couple of days and have not been able to check out the recent posts. I will answer all inquiries with this post and want to thank everyone as well. I get power, or at least my voltmeter said it registered 12-13 volts, at the connector under the crossmember. I was not aware of the second relay for the fog lamps, I will check that tomorrow. I believe I am going the LED route as well in regards to the backlight issue on my switch. I will try and get pictures of my rig posted, I am sure everyone will be impressed with the work I have accomplished... I was in Edenton, NC this morning with channel 9 on work related stuff and they were more interested in my truck than the news at hand...Thanks again...tom