ewarnerusa

I have some dual fog and driving lights. The fogs are 55W H3's and the driving lights are 100W H3's (originally 55W's). I have not had any problems with them. They are controlled by a single 2-way rocker switch inside, even though each set of lights has its own relay. I hardly ever use the driving lights, but I have wanted to wire them to the high beams for a while. I went about doing it by just bridging a wire from the high beam power right behind the headlight to the wire going into the relay from the interior on/off switch. It works fine, with the driving lights turning on with the high beams, and also illuminating the interior switch saying that the driving lights are on. The switch will no longer turn the driving lights on and off, but that is not a big deal to me. I am curious as to why, though. Initially, the fogs also worked normally. So, I successfully wired it so it would work. Was this the right way? is there a better way?

THE PROBLEM: I keep blowing fuses. The lights share the same power wire with a 15A fuse. The interior switch is also fused with a 2A fuse. I have never blown these fuses, even with the 100W light bulb upgrade. But now, the switch fuse keeps blowing. I think it blows when I turn the fogs on, regardless of if the driving lights are on. I have upped this fuse to an 8A, then a 15A, and it keeps blowing. The main power fuse also has blown, so now it is at a 25A fuse. Now I have 25A fuses in both locations, we'll see if it still blows. Why is this happenening?

ewarnerusa

I have cut my jumper in the meantime and have gone back to "stock". Everything is working as it did before I started. I also downgraded the fuse to the switch.

ewarnerusa

wow! nothing yet!!!?? This is the wiring diagram to the fogs. the wire I tapped into is the brown wire.
http://www.hellausa.com/optilux/newo...structions.pdf
the wire behind the headlight is red with green stripe (if I remember right). I checked with a multimeter first, and this wire has 12V across it only when high beams are on. I wish I would have checked the current, too!

WT

First off never change fuses to a larger value unless you like to maybe turn your truck into a flamming truck since they are rated that way to protect the wires from frying and smoking. Just a FYI
Okay just took a quick peek at the PDF supplied and yes the brown wire looks like a the right wire to supply +12V to turn on the relay which in turn will turn on the driving lamp relay.The problem with the fuses blowing is because your feeding +12V back into the fuses when you turn on your highbeams and the switch at the same time. I would suggest putting in a 2A fuse (this will help prevent to much current from cooking your jumper if something were to happen) on your jumper and also getting 2 diodes from say Radio Shack or another electronics shop and put one in line with your jumper and cut the wire comming from your switch and add the other in series there also this will prevent the +12V from back feeding into the switch and also prevent back feeding from the jumper. I'm pretty sure this will get you what your looking for. Some one correct me if I missed something here.
Good luck let us know how it works out.

ewarnerusa

yeah, the fuses are all back to normal. the problem was indeed the 12V going back into the switch. so the simple solution was to just remove the connection of the brown wire to the switch. everything works fine now. I actually just put a 2A fuse into the jumper wire, too. the diode thing to the switch sounds interesting, though. A diode just let current run one way, is that right?

WT

Good to hear all is working. Yes the diode blocks current flow in a single direction so this would if done right allow you to turn on the driving lights with the switch when the highbeams are not on or let the highbeams turn it on. If you decide to go with diodes just make sure there rated properly.

ewarnerusa

That's a good idea. I think I'll look into so I can have more control over when they are on or off. Thanks for your help.