Since I've been doing a lot of electrical fixes on my van recently, I thought I would tackle an issue that has long plagued me. My friggin headlights.

My headlights typically work only about 30% of the time. If I even think about using the high beam foot pedal, my headlights maybe work 10% of the time.

It's so awful, that I've installed auxiliary driving lights that are actually better than the dumb stock lights. For the most part, I run my auxiliary lights as if they are my regular lights.

But no more. I'm going to figure this ******* out once and for all.

Just some background: I have thrice replaced my footpedal switch with different brands, and it appears to have zero affect on my headlight functionality. I have replaced my headlight switch with a new one about a year ago. It seemed to help, but negligibly. I've cleaned any pertinent grounds under the dash.

The way it behaves, I think this is a switch issue. If I fiddle with the headlight and foot pedal switches, sometimes I can get the headlights to turn on. The headlights never just turn off on their own. However, I've replaced the switches a few times and new switches don't seem to make anything better.

All the other lights associated to the high beams (dash illumination, blinker lights, rear lights) all work without any issues. Just the head lights are affected. No fuses are burned out.

Is there a relay or something that is acting up? Is there a headlight relay that is technically working, but periodically malfunctioning? Anyone have any ideas? Is there a ground in the engine bay that I should investigate? Is there a fusable link that is sometimes working?

 

Ughhhhhh. There are great drawings for the bronco and the f-series trucks, but when i got to the e-series pages, here is what I see:

 

Check the wiring/connections at the switches. The trucks are well known to melt the connector, so a replacement switch still won't work right. You can get replacement pigtails to replace the melted stock connector. I had to do that on my '88, the middle was burnt and melted with the wires no longer held in place so they wouldn't connect to the switch.

 

agreed. replace the pigtail to the switch. and inspect the switch too, the bad pigtail may have ruined the new switch.
once you replace the pigtail and switch, do a headlight relay setup under the hood.
by doing the relays, the headlight switch becomes a low current device that only powers the relay and will last forever.
the relay will be wired directly to the battery and become the high current switch the way it should have been done in the first place.

 

Excellent advice. While i was searching for answers last night, I found those pigtails on Rock auto and thought that could have been a problem. For $8, that's a pretty reasonable place to look.

If there are no burns on the pigtail, should I replace it anyway? When i replaced the headlight switch last year, I remember it was not melted. I'll check again. Also, I remember I replaced the switch with something at NAPA up in the northwoods of Wisconsin (no other choices). But I just ordered a Motorcraft genuine switch last night which appears to have better reviews over the generic brand switches.

Also, I was looking all over for grounds that might be by the blinker or head lights, but none of my Ford books have a diagram that extensive. Does anyone know if there is a headlight ground behind the grill, or are all the grounds under the dash and on top of the fenders?

 

i would replace the pigtail even if it look good. it is old and the connections can deteriorate to the point they may be loose. this is what cause the heat and eventual melting.
headlight and blinker grounds should be close to the lights, i would say within 6-8 inches of the light buckets.

 

That's what I thought too, but my diagrams don't show anything other than top of the fender. I don't want to pull the grill off, but I'm thinking it's the only way to go.

 

I have plenty of relays in the garage. Will a 30amp relay work? or do I need something bigger?

 

sure will. figure normal use should be about 6-7 amps per light. so a 30 amp relay will be more than enough. i prefer to use 4 relays and a circuit breaker between the battery and relay. one for each low side and one for each high side.
most people only use two relays, one for low beams and one for high beams. .
i use 30 amp relays and a 15 amp circuit breaker in the power line before each relay.

 

That's plenty big enough, your lights will only draw around 10 amps assuming standard 55w/60w bulbs. You can oversize the relay but be sure to fuse for the wire size. I run 14ga wire and 15 amp mini self resetting breakers for high and low beams. Relays are 35 amp ISO 280 micro.

 

Why? That takes up significantly more space and more time, effort, and materials to wire it up, while not offering any appreciable benefit that I can think of. If a relay fails just pop in a spare or swap your low beam relay in place of the high. Also, I wired mine up such that I can just plug the original wiring back in at any time if there is a failure.

 

mainly so i do not have long runs. i have two relays behind each light, powered off the battery that is rite there.

 

You guys have so much room on your trucks. finding room for extraneous relays and wiring is a large project for van guys.

 

i keep forgetting you have a brick on wheels!!

 

I just checked out the grounds. I pulled the grill. From what i could investigate with my flashlight and mirror, there are no grounds for the lights and horns accessible or visible from the front of the van. So I'm pretty confident there are no grounds near the headligths on van. But there are some on top of the fender, so I'll re-clean those as well. But i'm leaning toward this being the pigtail and/or switch. new pigtail and motorcraft switch is in the mail.