This is my first post so I hope I am doing this right. I posted this in the wrong section earlier. I'm actually trying to get some help for my boyfriend while he is at work. His headlights are not working. The running lights work, but the high/low beams don't. He replaced the multi-function switch yesterday, but still no lights. There isn't any melting issues as I've read have been happening to other people so I was hoping someone had other ideas as to what is wrong.


The second problem is also another common problem I read about. When driving a distance over 30 miles he loses power until he downshifts. Then the problem is gone and doesn't come back. Sounds like the IP is going or needs to be replaced. He was thinking that he should just get the Edge to monitor it until it goes. Is this the best thing? Or would someone suggest just replacing the IP first?

Thanks in advance for your help and hopefully I didn't mess this up. The year on the truck is a 98.5.

 

sounds like an injection pump possibly, if you can find a diesel shop that will scan it for free, my guys do, you might be able too see whats wrong with it.

 

Could be many numerous thing on the headlights. I would take a guess at the switch if neither high/low beams work. As for the no power, I would have it scanned or wait before just up and replacing a 1k dollar part.

 

Well I'll throw in my 2 cents. Has he checked the Headlight relay? Possibly a fuse? Just curious as to why he changed the switch?

 

could also be the hi/low switch stuck...try flicking that a few times

 

He checked all the relays and cleaned all the grounds. The switch was the easiest thing to change. He is getting reverse polarity at headlight plug. That's about all the new information I have. Still not working though.

 

Lights are not dependant on polarity. If he has power and ground. The light should work! Is he sure all the bulbs are o.k.? Don't check wiring problems with a voltage meter either. Always use a load ( test light ) and sometimes you need a bigger test light ( homemade ) like an old glass headlight and a couple of jumper wires.

 

Found the problem today just a loose connection under the dash... Thank you all for the help...