what is the best way to wire fog lights in a 99 blazer? I am going to mount them by the tow hooks, how should I wire them? some instuctions say to the bright lights, some say dim lights and others say direct to the battery and mount switch under the dash. Is there a standard way ? is there a wiring diagram?[8D]

 

imho opinion itd be better to run them to the battery on a seperate switch, with wiring it into your main drive lights then you'd risk shorting them out and then all hell will brake loose.

 

I place a lighted switch in the cab of the truck and pull power off the parking lights. Run that out to the engine compartment and to a relay. Draw power for the relay off the battery, or in your case the underhood fuse box (fuse it). Then run the wires to the lights. Ground the lights to the frame, anyplace convienent.

With that set-up. I cannot turn the fog lights on unless the parking lights are on. This also turns the lights off when I turn the truck off. Plus when the lights are on, the switch lights up. There is no need to worry about the amperage draw through the switch, or trying to install a fuse in the cab fusebox. Not much space under that dash to work, especially to tap into the fuse box. Plus if you run the power needed to operate the lights through the switch, you can melt the contacts in most plastic switches, unless you buy a heavy duty switch rated for the amps/watts of your lights.

A standard relay can handle up to 30 amps, and it seperates the power needs of the lights from the power needs of the switch. In essence the switch is used to activate the relay, and when teh relay is turned on, it turns the lights on. With the relay drawing power for the lights off the battery, you don't need to run large wiring into the cab of the truck, just from the relay to the lights.

Look for a light installation kit that comes with the relay, cab switch, and all the wiring you need. Like $10. Comes with instructions as well. Click for Kit


There is a way to run the fog lights through the GM body control modual, however if your truck didn't come with factory fog lights, you will have to have the dealer activate that function. I don't think its worth the money. If you decide to go through the body control modual, then you can buy the GM factory switch with the fog light switch on it. Replace your current lights witch. You will still need the relay, put it cleans up the in cab installation, gives it the factory look. If you cannot find a suitable location to mount the switch, that might be a good way to go.

 

hooking the to to park lights sounds like the way to go, where is the best place to do this by the dash switch or the fuse box? is there a brand name for a relay? can you recomend a place to get one?

 

Considering the fact that true fogs should be used when conditions are bad enough to warrant them, wiring them in with the high beams would be pointless. The point is to get the light under whatever it is that is obscuring your vision (or reflecting too much). So if you were to wire them to come on automatically, you could do so by tapping into the low beam +12v wire. However, I would not recommend pulling fogs and headlights off the same wire. I would wire in a relay for the fogs so that it can be powered by a wire to the battery. Too much current draw (ie from the lows & the fogs) through the wimpy factory wires could melt them down.

Regardless of how you wire them, I would put in a relay. That means that you wouldn't be running a higher load into the switch which will only extend the life of the switch itself.

 

I like to tap into the parking lights right behind the factory light switch. Pull it out, find the correct color wire in your repair manual and tap into it.