This morning I lost both headlamps simultaneously. I've checked all the fuses (all good) and everything else electrical on the truck appears to be working perfectly (including all the other lights).

My Owner's Manual states "The headlamp assembly has a circuit breaker as part of the switch assembly."

What do I check next?

Thanks in advance.

Jim

 

Your lightswitch.....

 

By chance, did your headlights die when you were going from low beam to high beam (or vise versa)?

Try actuating your headlight dimmer switch several times. The contacts may have built up a resistance.

 

No; I was idling in traffic and they were suddenly gone.

Where is this "circuit breaker" referenced in the OM?

 

You're a genius! That fixed it. Tell me again what was happening here?

And many thanks.

Jim

 

Voila, Presto digitoe....lol... way to go, RuralCruiser

 

The main problem is that the contacts get dirty after years of use. Factories put grease on the contacts and it collects dust. Every once in a while you get a "dirty" contact and your lights dont work. To clean them you will actuate the switch.

I have seen with certain models that smoke will come out of the steering column from the grease heating up.

If you want to get energetic you can take the switch apart and clean out the old grease and use some new dialectric grease as lubricant.

 

Or put a REAL dimmer switch, in the floor, where it belongs.

 

 

Still could be a failing headlight switch. Before I installed relays my failing headlight switches could be brought back to life a few times.

 

I doubt it.

When my multifunction switch malfunctioned, I lost both headlamps but still had parking lights. I'm guessing when the in-dash headlight switch fails, ALL the lights controlled by that switch will cease to operate.



I too have installed relays -- the kit from Painless Performance took less than 15 minutes to install, including bolting the relays to the back of the fender well.

 

The parking lights still work with a bad switch, or at least that is what I've read in most posts and what I experienced. I just realized the OP was from 2007...still relevant I guess.

Didn't know there was a kit, I just made my own from Jim Lane's directions.

 

I relayed mine the hard but inexpensive way. There is a good diagram in the sticky. Running the headlights through relays reduces the ampereage across the headlight switch significantly. It also allows the use of heavier wire to the headlights which reduces voltage lose and makes even the OEM lights look good. Replacing all those parking and auxiliary lights with LED also reduces the load on the headlight switch. If you trailer it isn't a bad idea to run the trailer lights off a seperate relay too. This I haven't done yet, but the trailer I tow is all LEDs.

 

Simply replacing the parking light bulbs with (expensive) yellow LED bulbs does not work! See this old thread for details:

https://www.dieseltruckresource.com/...hlight=blinker

I'm running LED bulbs in my tail/brake lights, backup lights, side marker lights, and cab marker lights. But not in the parking/front blinker lights.

 

The parking/marker-light circuit can be relayed away from the head-light switch.

Simply clip the marker-light wire a few inches away from the switch-connecter pigtail.

The clipped end closest to the pigtail becomes the relay trigger wire.

The other clipped end becomes the LOAD from the relay.

Of course, longer lengths of wire need be spliced onto these clipped ends to reach the relay's location.

Although this will not provide for larger AWG wire to the marker-lights, it will take all the load away from the switch.