RockinFX

I recently acquired a Class C RV based on the subject chassis and have a problem I cannot track down. The high beams will not come on (low beams are fine) even though the multifunction switch appears to be operating fine and the dash indicator light comes on. There are several items I need to clear up in order to even begin so any help will be gratefully appreciated.

1) Are there separate fuses for L/R low and L/R high beams? These are composite headlights with separate bulbs for each and previous vehicles I have had were separated by left and right (and low/high when composite). It seems unlikely to me that both high beam bulbs fried simultaneously so I am looking for some common point. The wiring looks good.

2) Is/are the fuse(s) for the headlights in the relay compartment under the hood near the driver's side front fender? The wiring diagrams I have are unclear. The trim piece obstructing that box does *not* want to budge.

3) It is possible that packrats gnawed on something although I see no apparent damage. Is there an exposed point for the high beam circuit in that fuse/relay box or elsewhere that I could use a voltmeter on?

4) I am assuming that the low beams are switched off whenever the high beams are switched on (at least that is the behavior I am seeing) - is this correct?

As an old duffer whose income has been "fixed" in a similar manner to the way my dog was "fixed", I'd like to at least take a shot at debug. Sorry if these are noob questions - I'm a noob!

Thanks!

dberladyn

The very first thing you should do is go to Repairproceedures.Com, pay the $5 for 24 hour access and study the schematics of your van. I have all of mine, plus a few other years. With those schematics, you can eliminate half of your frustration. You'll have facts and not hearsay.

I didn't read much further than your requests for electrical info, because without you doing that I am wasting my time. I don't know about your year, but the BCM gets information from the Multiswitch and it decides if the high beams come on. If it decides the high beams come on, it sends a signal to a relay which does the actual switching. Of course there's a fuse in that whole system too. But there's many things in the process of turning on high beams, and if you understand the schematics, there's many ways to check and rule out possible problems.

canucklehead

According to my diagram. There is a main 40 amp fuse for all the headlights high and low beam under the hood. If you have low beams its likely ok. Then after the headlight switch on the dash, it splits power to different bulbs. Yellow wire goes to the dimmer switch on the steering column......from there, low beam is tan wire and high beam is lt green.
In the fuse panel there should be 4 separate 10 amp fuses one for each bulb. right hi low, left hi low. The lt green wire is the hi beam circuit and is that colour through the fuses all the way to the bulbs.
Start by checking all fuses. Then get a test light and test the lt green wire at the bulbs and poke into the wire a few places back towards the fuse panel by the emerg brake......
Make sure your grounds are in good shape too.
If the cluster light is coming on, then power is getting to the fuse panel.....start there.

dberladyn

You should state your year, because I don't think for mine any of your stuff applies. He's 2001 so, much different than me.

canucklehead

Its in my profile.
2002 express passenger ls. My haynes repair manual has diagrams for up to 2002 and for 2003 on.

dberladyn

I only have schematics down to 2008. I wonder how the OP is making out?