Headlights

[Charley67]

Headlights on my 2002 32V, f53 chassis not working on dim. All four work on bright. Is there a fuse? Is it more likely to be the controller in steering column?

[rk911]

i'd swap out the bulbs first.

[Charley67]

Originally Posted by rk911

i'd swap out the bulbs first.

They’re seals beam units. If they come on for high beam, that should indicate they’re okay, I think.

[Eagle5]

The low beams are a different filament.

[Wyatt]

Originally Posted by Eagle5

The low beams are a different filament.

Ditto, a REGULAR bulb has two jobs, (e.g. hi and low beams), then it has two filaments. One might work, while the other could be shot.

[Morich]

Question for me would be to look at what is somewhat easy and what tools are on hand. If you can get one headlight out or reach the plug on back and a meter is onhand, I would first look for battery which changes as I move from low to high beams.
You are likely to find three pins/lugs/connection on the lamp wiring and one will be ground. I would first put one meter lead on the frame or other metal that I know is ground and then look with the meter on ohms setting to find which lead has little to no resistance to ground. In other words, ID the ground lug first and then find which of the two remaining lugs is hot for high beams and the last one should go on and off with the low beams. On some bulbs you can look inside well enough to spot which wire goes out the back.
Lights are expensive enough that I am slow to go for new ones until I know they are the problem and there are always other things like the switch inside and wiring as well as corroded connections at the bulb, so I do the testing first and the paying second!

[Charley67]

Ditto, a REGULAR bulb has two jobs, (e.g. hi and low beams), then it has two filaments. One might work, while the other could be shot.

This is 4 rectangular sealed beam bulbs, where the two outside are designed to remain on, when lights are on low beam, but the inside ones are Togo off. As I understand it, they do not have multifunction like a vehicle with only two sealed beam bulbs. They are high and low beam by virtue of their adjustment and whether two or four are on at any given time. Am I wrong about that?

You are likely to find three pins/lugs/connection on the lamp wiring and one will be ground.

Mine only have two lugs. I’m suspecting a problem with the multifunction switch in the steering column, unless there is a relay. Does that sound reasonable?

[Charley67]

I found the relay, and that was the problem. Got’er done! Thanks for your replies. I have found help for so many things on these forums.

[rk911]

Originally Posted by Charley67

They’re seals beam units. If they come on for high beam, that should indicate they’re okay, I think.

i meant the entire headlight. the low beams should be a different filament. simple things first.

[dacap06]

With both out, it is unlikely to be burned out filaments.



Get your multimeter out, pull the electrical connector off the lights, and look for power on the pins with highs on and lows on. Measure from a chassis ground to each pin and between all combinations of 2 pins.



If you see no voltage on any pin when in low beams, it's wiring or the switch. Not likely a fuse -- normally, the same fuse handles both high and low beams,although you probably ought to look at your model's schematics to confirm, if you can get them from Ford or Winnebago.



If you see voltage between two pins, it will either be a bad ground or a burned out filament. Measure the resistance of the headlight between the headlight's contacts corresponding to the two pins with power. If it is infinity, the headlight is bad. If it is anything else, it gets complicated. Bad grounds can create squirrely and confusing symptoms, so I'd take it to a Ford shop if you don't have in-depth electrical knowledge.

[Charley67]

Thanks, Decap06, it was a 5 prong relay.