Got a 94 F150 and the low beams quit working. Hi beams work and hi beam flash works. Replaced the mutifunction switch and checked all the fuses we could find. Also found a relay that felt like it was turning on and off as the headlight switch was pulled in and out. Swapped the relay with the one next to it but that didn't help. Any suggestions????

Also thanks to all for the help on the vibration at 30mph problem. Had all the u-joints replaced and that took care of it.

 

i'm assuming you did but you don't mention it, did you check the bulbs themselves?
also if you have a test light, see if you have power out at the connector to the bulb.

 

I didn't check the bulbs as I didn't think both bulbs would go out at the same time. I did check for power at the connector and didn't have any. Can't find a decent schematic on the electrical system. Suggestions??

 

i don't have the separate wiring book of the factory manual but basically i would just start at the headlight and work my way back on the harness, checking for power. You'll see the color of the wire and tracer at the headlight, that will help you on your way back.
if you have no power at the connector then i guess your bulbs are fine, just wanted to eliminate them.

 

I have worked on cars that did burn out both headlight and all the running lights at the same time, a small voltage spike fried the bulbs. While this is uncommon it could happen so check the bulbs to be sure.

 

Thanks for the help. Not sure what I missed on the first time but I went back and checked for voltage at the headlight connection and sure enough had 12 volts. Checked the bulbs like DixieDarkhorse suggested and both low beams were blown. Thanks again.

 

thats funny

 

glad you got it fixed.