I have an issue that developed after i did a gm one wire install. i was driving my truck with the low beams on and they just shut off. I still have the high beams that function just fine. I have a Hella H4 upgrade and the fuse holder on the H4 harness was a ceramic lined fuse holder, until the ceramic crumbled and power arced across the terminal around the fuse..... I have changed the fuse holder, added a giant blade fuse inline from the alternator to stop it from even getting as far as my headlight harness again. I have changed to fresh H4 bulbs and well as checked the two relays on the headlight harness AND the two on the truck's cab harness, all checking out fine. Both interior fuses for headlights are fine also. Is there anything anyone else can think to check out? I'm stumped.

 

I wonder if the short circuit damaged the relay. I think there are two relays under the dash, one for high beams and one for the low beams.

How did you like the H4s, when they were working? I wasted a bunch of time trying to get a pair of LED lights to work. Thanks to Toyota's fancy way of switching from low to high beams, they can't work. If anybody cares, Summit has a great return policy.

 

has anyone experienced this, I've found one similar thread but it was a third gen with a burnt pin in the column plug. Mine didn't turn out to be the same thing. Im going to try taking off the light/turn signal switch and checking out the connections, maybe i melted some solder.....I don't have a clue, any takers?