I had after market fogs added to my 2004 F150 SCREW.

Everything ran well for a few weeks and now the following do not work and all stopped working at once:

Factory Fogs, which have brighter bulbs than stock.

No interior overhead console lights when the truck is in operation, but they do turn on when the doors open but truck is off.

No vanity mirror lights.

Can anyone tell me exactly what the problem is? And if it is a relay or fuse, can I step it up a small bit to take the load?

 

I'd be willing to guess that whomever installed your aftermarket fogs, just tied into your stock wiring. The fuse is there to handle too many amps. (every light uses amps, and add enough lights (amps), it'll blow the fuse). When the factory wires it, they use wiring big enough to handle the load, by taking all of the lights on that wire and make sure the wire can handle it, and putting a fuse that can handle the load and blow before the wire "blows". I think you have one two many lights on the circuit. However, my guess could be totally off and the aftermarkets were installed on their own circuit......hope this helps in the diagnosis. Don't just put a bigger fuse in. It's there to protect the wire!

 

Am not sure how they wired the after market fogs, but they still work, while the other stuff does not. would a 5 amp increase in a fuse make that much difference?

 

I don't think anyone will have the guts enough to answer that question. It's easy for me to say 'yes' because, well....it's not my truck! That wouldn't be a correct answer though. When all is said and done, the fuse needs to burn before your wiring burns. However, if your fogs are working and none of the others are, it's pretty safe to assume that they aren't on the same circuit. It either all works, or it all don't work! I'd do some underhood looking to find out what's wired where.

 

Im not sure its a fuse unless your overhead lights are powered through a different circuit when the truck is off with the doors open which could be the case, but just sounds a little funny to me. If you have found a blown fuse then yes try replacing it with a bigger one. Really need a schematic, Ive been looking for a schematic, but have not found one. If you or anyone knows of one please let us know, it would be a great help.

 

I wouldn't put a bigger fuse in!I'm an Electrician and I can tell you that could make it alot worse.When figuring power usage the maximum load of a circuit is calculated and then you add 25% more for the to fuse or breaker rating and size of wire to handle the amperage.putting a bigger fuse in will let the maximum amps(or load) exceed what the wire can handle and guess what?The wire gets hot and then the insulation melts leading to a possible dash fire.NOT RECOMMENDED.The outside panel has 12v power in quit a few empty slots that can be used.Thats what their there for.I would get your owners manual out and check to see what each fuse goes to and hunt down wich one is the interior lights and see if the fog lights are tied on.If they are I would put them on a circuit of their own.

 

If your lights are installed correctly, they should have a relay. The installer may have tapped into your interior light fuse for power to the relay. Depending on what side of the fuze he tapped, it may have blown the fuse, but still has power. I would take it back to the installer and make him fix it.

Also if you added brighter bulbs to the fog lamps you may have overloaded that circuit. It may work fine for awhile and then you take a long trip at night with the lights on and it blows the fuze. Check your fuses, and put the stock bulbes back in and try it. If all else fails, unplug everything, put it back to stock and try to fiqure out what is installed wrong.

good luck.

 

Electrical circuit safe design is very specific.
These are, power consumptions to be condsidered first, then what parts capacity to use then where and how it will be powered and controlled.
Not following these considerations will always result in problems.
We here don't know how your system was altered or wired to be of any specific help.