

| Subject: | FW: Help! |
| From: | Carrington, Tom |
| Date: | Mon, 10 Jul 2000 23:33:42 -0400 |
> -----Original Message----- > From: David Beierl [SMTP:dbeierl@attglobal.net] > Sent: Monday, July 10, 2000 11:25 PM > To: bpchristensen1@home.com > Cc: vanagon@gerry.vanagon.com > Subject: Re: Help! > > At 14:00 7/8/2000, bpchristensen1@home.com wrote: > >Headlight problem; low beams work fine, but when I switch to high beams, > the > >high beam won't light on the driver's side, and the primary filament in > the > >main lamp goes out. > > By primary I assume you mean the low-beam filament. It's actually > *supposed* to go out when you put the high-beams on. Low beam is driven > by 56b (through fuse s21 for left side and s22 for right). High beam is > 56a, s10 and s9. The dimmer switch simply switches the 56 lead from the > light switch (which gets its power from the load reduction relay, X > terminal on the light switch) to either of 56a or 56b. So: > > 1) bad ground from that headlight assembly. The low beam still works > because it's grounding through the high-beam filaments, just like the guy > ahead of you whose running light goes out every time he puts the brakes > on. His running light is grounding through the stop lamp filament, but > the > ground goes away (and neither light works) when the stop lamp is > energized. > > 2) bad s10 > > 3) bad internal panel wiring, fuse s10 to terminal c17. > > 4) bad 56a wire from panel to light assembly. > > My bet is on number one, but you can check by testing for 12v at the > separate high-beam lamp (highs switched on, duh...). If you have 12v > there, it's a bad ground. If not, start following the other stuff back > until you find 12v. It's not the switch, since the other side works > ok. If you have voltage on one end of something and not on the other end, > > that's the busted part. > > > >I notice that in the wiring diagram that each lamp has two circuits - 56a > >and 56b, and both sides tie together somewhere behind the dash. > > High and low beams. > > >I checked for continuity in both circuits from the dimmer switch (and the > >dimmer switch itself) and everything seems good. One weird (?) thing I > >noticed was that the "hot" side of the 56a circuit had continuity to > ground. > >Is this just due to the bulb? (i.e. not abnormal). > > Hot resistance of a 65-watt headlight bulb is about one fifth of an > ohm. Cold resistance much less...normal. > > > >Any suggestions? All I can think of is a short in the wiring between the > >driver's side lamp and the dimmer switch, which I imagine will be a > >nightmare to troubleshoot. > > That's not it...an open maybe, but no short. And no problem to find if > you > need to. :) > > cheers > d > > David Beierl - dbeierl@attglobal.net <<- New address becomes mandatory on > 1 > Oct, optional until then.
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