Changed Master Cylinder, Great! Now, HEADLIGHTS DON'T WORK!

[estaño cima]

Hi,

I know there are a ton of threads on this, I've read at least a dozen so far. I thought it wouldn't hurt to explain my specific situation as perhaps this has happened to someone before.

The van is an 83.5 (water-cooled). I noticed a small drip of fluid on the floor below the clutch pedal the other day... traced it back to where the master cylinder was bolted on. Purchased a replacement cylinder and some fluid, followed the procedure written up on vanagonauts and all went well. The only hiccup was that one of the electrical switches attached to the MC (the one closest to front of van) had burned out at some point in the past so I replaced that as well. Red herring?

I put everything back together and the brakes work great but the headlights do not. They were working fine before, the headlight switch would activate the lights.

Based on the threads I've read it seems like it's likely one of the following:
Grounds (check and clean at the "star" behind the fuse panel)
Headlight switch
Hi/Low selector switch
Ignition switch
Bulbs

The grounds appear fine, I removed the spades from the star, (cleaned) and replaced. No change. I'll go back in and clean with steel wool and try again. I'm a little skittish about pulling on too many wires in there.

The ignition switch appears to be working normally, the van starts, the fan works, the radio works. When I jiggle the wires below the switch while trying the lights nothing changes.

The bulbs were working before, I can't imagine they stopped working while not running but??? They do work when I hold the switch in just the right place.

That leaves the headlight switch or the high/low switch (or maybe something else?). When I try to activate the high/low I don't get a satisfying "click" like I would expect. I can get the lights to come on if I hold the switch in just the right spot but it's not safe for driving like that. Before this I would always leave the highs on (as advised by the PO) because I was told these things act up and the highs were only really as good as lows in a more modern vehicle. So I have no real history with this switch. The headlight switch had been working fine to turn the lights off and on. I pulled it off, pulled it apart (in half) and everything looks fine, no smells or obvious damage. I cleaned the terminals and plugged it all back in and nothing changed.

I've got a test light, a voltmeter and a Bently but not much experience when it comes to automobile electronics.

I'm heading back out to the van to pull and clean the grounds again.

I guess the next step is to test each of the switches. I'm just not sure how.

Any help is greatly appreciated.

Thanks

[estaño cima]

Update:
With the test light I checked the headlight switch. Switch turned off, upper wires hot, lower wires not. Switch turned on, upper wires hot, lower wires hot too. Maybe that eliminates this as a potential culprit?

[Wellington]

[estaño cima]

I should clarify, I can (or could) get the lights to come on when holding the high/low switch in just the right spot. That doesn't seem to work now. The test light seemed to indicate that the main headlight switch was working.

Thanks

[vanagonjr]

I'd still focus on the grounds - but mainly redoing the 2 into 1 headlight ground at the star - see my post below from another thread.

[estaño cima]

Ok. So I think it's the high/low switch. Pulled it off the column, cleaned it. I think it's a little mechanically worn out. One of the tiny clips that keeps it together is broken. Played with it, cleaned, reinstalled, fiddled with it for a bit, heard a satisfying click and voila, lights work as before. Good to have gone through cleaning grounds and getting familiar with the way this system works. Will be ordering a new high/low and replacing as this is a little precarious. But glad to be able to drive at night for now

Will post update after new switch reinstall.
Thanks group.

Cheers

[estaño cima]

Thanks to all who chimed in. Turns out it was a mechanical failure in the hi/low/blinker/wiper switch assembly. The PO had opened it up for some reason and in so doing lost the small, white plastic "wishbone" piece that helps the switch (activated by the high/low lever but physically located below on the wiper assembly) move to either the high or low beam setting. Tracked down a switch assembly at a local repair shop and used the "wishbone" and cover from the used part and now it works like new.