OK, so I am searching for info but not found anything yet. This goes back a couple years. About 1.5 - 2 years ago I bought a HD headlight harness, actuall 2, one for my '05 (6.0l) and one for my friends '02 (7.3l).

Long story short, both harnesses worked perfect. I proceeded to add some Internet purchased h13 bulbs that were border line not DOT approved. About 2-3 months later my friends headlights went out. He went back to the factory harness and no problems, other then lots the brighter light. Like clockwork 2-3 weeks later my harness did the same thing. I went back to factory, left the high output bulbs, and things worked perfectly... until the passenger side bulb melted the factory harness plug .

I am now looking for ways to fix my truck and re-add brighter lights to both trucks. In reading I realize that some people say on the diesels you need a different harness, one for each battery. Would that have caused the single battery harness to pop both relays on two different trucks? I see on Dfuser's web page that he has two different harnesses and the heavy duty harness says "Includes two (2) special harness each powering one side of your vehicle (Driver and Passanger side) Headlights and foglights" but also says the fog light switch will be disabled. My other problem is that the pass side h13 factory plug is melted so I can not connect a 2nd harness into that side for the off/on functions.

What do y'all think is the best option for my issue? I was thinking to buy a new plug (or junkyard one) and solder it back on, is there a better way? All that would do is leave me where I was before I started.

 

I bought Dfuser's harness and it only hooks up to one battery and one factory headlight plug. It does however run each headlight off a seperate wire and though a seperate relay (it comes with 2 relays). I am running it with Sylvania Xtravision bulbs and have been very happy with the light output.

 

How long have you been using the upgrade kit? The one I had only had one connection to one of the two batteries and one connection to the factory headlights but it also had two relays. But it still went out, both relays, within 3 months.

 

I've probably been running it for about 4 months now.

 

so what is a relay? is one going out what melted your wiring harness? Im asking because I have some lights on the front of my truck, always worked great and were on the truck when I bought it. about 2 weeks ago driving down the road with the lights on and the switch got hotter then hell and melted! I just put upfitter switches in the truck and I dont want to hook the switches up if theres something wrong with the light or wiring. Sorry for the thread hijack!

 

Here is a great site for explaining what a relay is and how it works, as well as showing how to wire them up.
http://www.classictruckshop.com/club...osch/relay.htm

It sounds to me like your lights were wired directly through a switch that was not rated high enough. You should rewire the lights through a relay off the battery and use the upfitter switches to turn the relay on and off.