Ok,

First off I don't have the stock foglights on my Bonnie anymore, I ditched them long ago.
Saying that, I'm not sure how much you guys might be able to help.

I've got Bosch Pilot150 Fog and Driving lights on my car. (as you can see in my pic)
Since I have the GTS covers on my headlights, I use the fog lights as my primary night driving lights. I have them hooked up to the overhead switch by my map lights.

Side note, the Pilot150 driving lights are hooked upto my highbeams.

The fog lights are on a relay, direct to my battery.
In the past 2 weeks, I've gone thru 4 fog light blubs, they keep blowing.
First the drivers side, then the passanger, then both at once.

I do have a aftermarket alternator in the car, and with my transmission issues, sometimes she'll rev to the red light and cause my battery light to come on for a brief second (while it'* in the red line).

I'm suspecting maybe too much voltage/amps/current....?

If you need anymore info, please ask.

Sounds more like a moisture problem to me. H3 bulbs do not like any moisture at all. Even touching them with your fingers will put enough oil on the bulb to generate a hot spot. Do you have any condensate in the housings/on the lenses?

Are there drain holes on the bottom of the housings? If so, they may be plugged which allows too much condensation to build up inside. Are the lenses gasked really well? If not, any moisture from the road can get in there and shorten the life.

When you see the red-line, do other lamps in the car seem to get brighter also? If it was an over-voltage problem, you would probably see more bulbs going out, especially the smaller bulbs in the dash.

Jay

I would have suspected road water and such too... except it hasn't rained in like 2 weeks or so. Just some minor showers.
No there is no condensation in the housing, and there are proper drainage holes, none are clogged.

I'm placing the blame on some type of electrical error. I don't notice the light getting brighter, and none of my dashlights have failed... yet.

The other possible culprit could be vibration. Lamps mounted on the bumpers are going to get alot more than something mounted inside the body cavity.

Jay

If the problem started suddenly the problem might be a bad ground (that alt light at redline makes me suspicious) causing the lights to act as a ground path & pass more current than the bulb is designed for. What does your voltage gauge read ?

Here'* an update....

When I went to drop the car off at the Auto Body shop, I noticed the highbeam lights (Pilot150s) were still on even though the car was off. :?

I started the car twice, and turned the headlights on/off and switched my highbeams on/off, and they went out.

Please note, my normal headlights and highbeams have always worked normally. My issues are with the two pairs of Pilot150s I have.

When I got the car back from the AutoBody shop, they said the lights gave them no other problems. I opened the hood, and checked the fuses and relays. Both fuses are blown.

Any suggestions?

padgett: My voltage gague reads at about 3/4 most of the time. When the tranny slips and she revs high, the gague goes full I believe, and that'* when the batt light comes on.

I just saw your lights. Might be too much load on the circuit. You may seriously try a larger fuse. You may want a bigger alternator, too.

Ok... two corrections from my last post.

When I inspected the fuses last night I thought BOTH had blown.
It turns out only the Pilot150 Driving Lights fuse (20A) has blown.
The Pilot150 Fog Lights fuse (20A) is ok, but both blubs are dead.

Also, I reved my engine upto red line, the battery light comes on, but my charge gauge does not go up to full, it stays around 3/4.

wilwren: I had my alternator replaced with a heavy duty one around 2 years ago. They told me it'* the type they'd use in an ambulance :? (I'm not sure about that) I don't have the make/model or anything, except a pic.

http://rubix.ca/Bonnie/Bathurst/011_merlin1_alt.JPG

I believe it'* larger then my other alternators, and I haven't burned it out yet... which is a plus. I believe it'* my 5th alternator in the car.... and hopefully my last.