How do I trouble shoot to make them work?

 

I would start with the simple stuff first. Make sure the fuse is good, then to check and make sure the bulbs are good. If they are, then see if the switch has power to and out of it when the headlights are on. Make sure the switch isn't set to dim. Check for power at the backside of the instrument cluster.

Unk Bob

 

Check the rheostat on the light switch. That is the most common cause.

 

I would 1st ck that the headlight switch is turned/rotated fully counter clock wise and just before the turn on and lock on the dome light with the doors closed notch. That is full bright on the dome light rheostat.

X2 ck fuse, ck power to switch. Be careful reaching up under and behind the dash to remove the dash light bulbs the circuit board and the cluster itself can be brittle. Worse case remove the instrument cluster and insp the printed circuit board condition. There are instructions for that here, I took one apart once. lol

https://www.ford-trucks.com/forums/1...then-some.html

It could be the headlight connection being bad and as always, clean your grounds and connections. https://www.ford-trucks.com/forums/1...ml#post1812190

 

If the ignition reostat is bad do I replace switch?

 

Pull the cluster, & replace all the bulbs & bulb holders with new ones. Clean the area on the PC where the holder makes contact with a pencil eraser. This is if the back is not crumbling like the one pictured above.

 

Yes, but you can remove the switch and try to clean it first. There is a little metal tab that is what rotates when you turn the **** and that goes around on the coiled up spring. Once you get it removed you will see what I mean.

To remove the headlight switch you will have to remove the dash bezel:

Dash bezel removal is first: Disconnect the battery, and reach up under the dash find the release button on the headlight switch. Push the button and pull the **** and shaft out as one piece. If you can not find it read on….

Then remove the 5 screws first. Far left between the headlight/wiper *****, there are 2 screws, 1 between the *****, and 1 above it, going in straight up. Moving right there are 2 more screws. 1 in the middle, 1 far right, both pointing straight up. Section heater control there is 1 screw pointing straight up.

Heater controls are in behind the dash plastic, they stay where they are, but you will slide/squeeze the levers out of way to prevent them from hooking on the dash bezel.

To remove the wiper **** it has a release clip on its shaft that you can put pressure on with small flat tip screwdriver in the tiny slot, press and release and slide the **** off.
Radio may be behind or in front the dash bezel, depending on how previous owner (P.O.) installed it. If its factory or shaft style, pull the ***** off the radio and you will see shallow nuts on the shafts. Clean the shaft threads with elec cleaner and small brush, because the shafts will strip VERY easily, use a deep set socket on them. Once the nuts are removed, there should be a plastic or metal radio plate to remove. Behind that are 2 more screws holding dash bezel to a metal bracket. But not always…

Okay, under the 3 sections that you see the gauges in, under the middle one there is a plastic tab from the dash bezel that is tucked behind the metal part of the dash. You can see the metal cutout area for it, when the headlight ****/shaft is pulled out or removed all together you can pull up on the plastic dash bezel to get the plastic tab out of the slot.

If you could not find the headlight ****/shaft release button earlier. With all screws out of dash and radio loose, you should be able to tilt it forward and see the headlight switch directly behind where the headlight **** is. So with the shaft pulled out like the headlights are on, you tilt the plastic dash bezel forward to get your hand above the switch and feel for a metal button to press and hold to release the headlight shaft from the headlight switch. **** and shaft will slide out as one piece with the button held down.

Cluster assembly is mounted with 4 screws, once they are out, CAREFULLY pull fwd on the assembly just a little. You need it fwd just enough to get a hand on the speedo cable white plastic connector. If you can not get it fwd enough, push yourself some slack in the cable from the eng compartment.

The using your hand (best idea) or a small pair of pliers CAREFULLY squeeze the white clip till the cable comes out of the cluster (the white clip will come with it). DO NOT PRY on the clip it, will break and then you have another issue.

Squeeze the side of the main electrical connector and it should release.