Help... I keep melting aftermarket fog switch

[Michigander]

Ok, I've gone through 3 switchs so far... what's my problem? I just installed these new Pilot fogs about 3 weeks ago and I melt 1 switch every week. The power is coming from the distribution box in the engine bay. I don't understand how I can be getting too much power to the switch. Please help me.

 

[JDraper]

Is your switch running a relay or the lights directly?? If you are running the lights directly, that is your problem. The switch should run a relay, which in turn controls the lights. Check out KC Hilites . I think they have a wiring diagram up for putting the relay in.

If you are running a relay, and still smoking switches, you either have a short or something backwards on the wiring.

 

[Michigander]

It has an in-line fuse between the power sourse and the switch... I figured that would stop any high power. Should I get the power from the smaller fuses in the dashboard?

It isn't running a relay. What relay do I use? How do I hok it up. I saw the diagram on KC's website.

I have it wired exactly like the KC website says I should for a non-realy wiring Dead Link Removed

 

[Sandy]

A relay should be put in line on any and all light applications; the head lights should have them also.

Add a relay in between the wire from the swtich and the lights. Run a separately fused power wire from the battery to the relay.

Good Luck,

 

[Michigander]

What exactly is a relay... I know I need one. What is it and how do I wire it in?

 

[codewiz]

Take a look at a page i put up:

Dead Link Removed

it is for a bike project i was working on but the principal is the same. You can get an auto relay at radio shack for about $5. The way it works is this:

You have a power input which is basically just a trigger from a power source. In your case, it will be whatever is feeding your switch like a fuse from your box, the cigaretter lighter, or whatever. You also wire up a ground which can be a ground to wherever. You also have a power input feed which connects to something that can handle the high current like (in my case) directly to the battery. Then you have the high current lead coming off of the relay which feeds your lights. In a nutshell, what happens is this:

When the relay receives some power from your feed (cig lighter & switch), it then 'opens up' and allows juice to run from the high current input (from the battery) through the high current output (directly to your lights). The wiring from the battery to the relay and from the relay to your lights will have to be of a gauge sufficient enough to handle the load, whereas the wiring you were using (say its from the cigarette lighter) to the switch is trying to pull more juice than the stock wiring can handle. The juice that goes through the wire that 'triggers' the relay doesn't take much of a load so you can use the stock wiring for that. Did that make sense?

-Kevin

 

[codewiz]

Here, check out this guy's page too:

http://www.classictruckshop.com/clubs/earlyburbs/projects/bosch/foglites.htm

 

[Michigander]

yeah, thanks, that makes more sense. I'll ty to pick one up at autozone. I'll post more if I still have problems.

 

[Michigander]

ok... one quick question.

I looked at the diagrams. There is a wire that runs from the 30 side of the relay through a fuse to the battery. Instead of that, can I just run that wire to one of the fuses on the fusebox in the dash of the X?

Thanks

 

[codewiz]

Well... it depends. The wiring to that fuse has to be heavy enough to support the load of the lights + whatever else is running off that wiring. I don't know what the specifics of the wiring running to the fuse box are so I can't tell you if any of them meet that requirement. That is the wire that is going to bear the brunt of the load so it needs to be thick and when running something as intense as lights, I would prefer to have them using their own power source and their own fuse.

-Kevin

 

[Sandy]

codewiz,
Nice site, I like the diagram of the wiring.

Michigander,
A relay is a device to control high power loads, (using higher than normal amps or long control wiring), through a low power switch.
Look at the site from codewiz, this one explains the relay itself:
http://www.classictruckshop.com/clubs/earlyburbs/projects/bosch/relay.htm .

In other words you use the relay, that is controlled by low power, to control high power; as you can see in codewiz's drawing.
I have used Radio Shack's relay and have replaced then after six months, I would at least use an Auto Zone or NAPPA HD relay.

Just to restate what codewiz said, do it that way and do it right. Use his site: http://www.classictruckshop.com/clubs/earlyburbs/projects/bosch/foglites.htm

Always wire in a fuse between the battery and the load, that way the relay and/or switch(es) will not get destroyed if an overload occurs.

Good Luck with the install,

 

[PsykoTone]

I had the same problem a while back, it was a bad ground near the lights themselves. I belive this caused alot of resistence to build up on the line itself. I had and still have my fog lights running off a relay. The relay gets it's "on" signal from my Parking lights and the ties my battery into my hidden switch (wich is usally on) and then to my fog lights, which i ground to my battery negitive terminal. I haven't melt my current switch and i keep mine on eveytime my running lights are on. Hope this helps.