Fog Out...?
Fog Out...?
Chronic Tool Dropper
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From: Bend, Oregon
Each fog light bulb has its own fuse, IIRC. Do the individual fuse blow when you put them in and turn the foglights on?
The bulbs are H-3 type, and can be purchased in the (standard) 55 watt versions, and also in brighter 100 watt versions. Using the 100 watt versions requires that you be extra careful in your lead dress and routing. The reflector easily gets ot enough to melt the insulation on the wire going to the bulb lead, sometimes shorting that wire to ground. That would easily cause the fuse to blow.
Following the instructions in the Owner's Manual for changing the bulb, remove the foglight lenses and look for wires melted to the reflector and also for conductors melted together. These are the sure signs of the problem. If there are no obvious meltdowns, it will take a bit more than a casual look to find the problem. Start with the look in the housing, and we can go from there if necessary.
No matter what, resist any urge to put larger fuses in there. The fuses are sized to protect the wiring between the fuse and the bulb from burning. Increasing the fuse size means the wire will get hotter before the fuse blows to protect it. Nobody likes fires of course, but you can cause damage that's harder to find, like wires melted together inside a harness that you can't easily see.
Let us know what you find, please.
The bulbs are H-3 type, and can be purchased in the (standard) 55 watt versions, and also in brighter 100 watt versions. Using the 100 watt versions requires that you be extra careful in your lead dress and routing. The reflector easily gets ot enough to melt the insulation on the wire going to the bulb lead, sometimes shorting that wire to ground. That would easily cause the fuse to blow.
Following the instructions in the Owner's Manual for changing the bulb, remove the foglight lenses and look for wires melted to the reflector and also for conductors melted together. These are the sure signs of the problem. If there are no obvious meltdowns, it will take a bit more than a casual look to find the problem. Start with the look in the housing, and we can go from there if necessary.
No matter what, resist any urge to put larger fuses in there. The fuses are sized to protect the wiring between the fuse and the bulb from burning. Increasing the fuse size means the wire will get hotter before the fuse blows to protect it. Nobody likes fires of course, but you can cause damage that's harder to find, like wires melted together inside a harness that you can't easily see.
Let us know what you find, please.
User
Joined: Jul 2001
Posts: 3,291
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From: Midland, Texas
Gretz,
There is some good info in one article on the Greg Nichols site,under the electrical topics.
You mentioned fuse not fuses so I think drbob has you covered with his mention of fuseable links (2 of em')should be at top and behind the fuse panel.
LOL
Keep em' rolling
John S. & Pattycakes
There is some good info in one article on the Greg Nichols site,under the electrical topics.
You mentioned fuse not fuses so I think drbob has you covered with his mention of fuseable links (2 of em')should be at top and behind the fuse panel.
LOL
Keep em' rolling
John S. & Pattycakes
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Joined: Jul 2001
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gonna tackle this soon..emailed Dr Bob with some questions...didn't know there were 2 fuses..I had this problem before last year..I seem to recall the mechanic saying it was a short somwhere in the line of miles of cable..??
gretz99
91 928 GT
gretz99
91 928 GT
Chronic Tool Dropper
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From: Bend, Oregon
I lied to the board:
-----------------
Turns out that, at least on my '89, the two fog lamps share a common fuse #30. In my collection of things along with me I happened to have a scan of the lighting wiring diagram in PDF format. Gretz, e-mail me offline if this will help you. I know you have a '91 but the foglight wiring probably isn't a lot different.
On the '89, fuse 30 is in the circuit immediately after the fog light relay. From the fuse, wiring goes out of the fuse panel at O-24 (oh-twenty four) for the left lamp and O-25 for the right, both of them in white-with-brown-tracer conductors to the front of the car. My diagram shows no additional connectors or connections in that O-harness between the main electric board and the light assemblies.
Hope this adds some light to the situation.
Each fog light bulb has its own fuse, IIRC. Do the individual fuse blow when you put them in and turn the foglights on?
Turns out that, at least on my '89, the two fog lamps share a common fuse #30. In my collection of things along with me I happened to have a scan of the lighting wiring diagram in PDF format. Gretz, e-mail me offline if this will help you. I know you have a '91 but the foglight wiring probably isn't a lot different.
On the '89, fuse 30 is in the circuit immediately after the fog light relay. From the fuse, wiring goes out of the fuse panel at O-24 (oh-twenty four) for the left lamp and O-25 for the right, both of them in white-with-brown-tracer conductors to the front of the car. My diagram shows no additional connectors or connections in that O-harness between the main electric board and the light assemblies.
Hope this adds some light to the situation.