'78 Bus Mystery Wire Under The Dash/Rear Window Defogger

[Westy78]

While trying to figure out where my mouse invasion occurred, under the dash I found this wire hanging loose.



It appears to be a factory wire and I think it goes to the rear window defrost knob. Possibly why my defroster has never worked. Before I plug it back onto the switch can someone confirm on their own rear defrost switch?

[IFBwax]

I'll check tomorrow morning if you can wait that long Jasan. As a side note, how are you able to get those great shots with no room to work back there? Seriously.. so you take ten pictures and hope one is in focus?

[Westy78]

I'll check tomorrow morning if you can wait that long Jasan.

That'd be great. Thanks Wayne.

As a side note, how are you able to get those great shots with no room to work back there? Seriously.. so you take ten pictures and hope one is in focus?

Yep, that's about it. Turn on the macro, aim at the general area and hope for the best. That shot took about eight attempts before the focus was actually on the switch and not some random wire or piece of dust.

[dtrumbo]

Here's mine.



I'm pretty sure you're correct. That's the defroster wire. If yours works just by hooking up the wire, I'll be SOOOO jealous! There are very few working rear defrosters in buses anymore. Typically, the grid on the rear window deteriorates and quits working.

[Westy78]

Thanks! That definitely looks like the one. I highly doubt that my rear defrost is actually going to work. Like you said, the grid isn't in great shape.

[bretski]

There are very few working rear defrosters in buses anymore. Typically, the grid on the rear window deteriorates and quits working.

Really? I'm sorry, guys.










Mine works!

[dtrumbo]

There are very few working rear defrosters in buses anymore. Typically, the grid on the rear window deteriorates and quits working.

Really? I'm sorry, guys.










Mine works!

Woo hoo! I would bet yours and BobD are among the few.

This has been beat to death over on TS, but has anyone successfully repaired their grid with that goo that you can get at your FLAPS that comes in a finger-nail-polish-style bottle? You mask off your window and "repaint" your grid lines with the stuff. I bought some, but haven't tried it yet. Yeah, yeah, it's on the list.

[bretski]

It should work. I'd be tempted to use conductive paint that is used for circuitboard repairs, though.

BTW, blast you! You made me go out and inspect my grid. It could use a little touch-up here and there...

[Gypsie]

Yeah, give it a try and let us know, I want to get mine working too.

[dcketh]

I'd be tempted to use conductive paint that is used for circuitboard repairs, though.

Keep in mind that whatever you use has to have enough resistance to get warm, as well as provide a load for the circuit. If it is conductive enough to act like a wire it will also act like a dead short and blow your fuse. I'm not saying it won't work, because I don't know, only that it might take some experimentation, which is always fun! On the otherhand, if you can find all the breaks then this would be perfect for repairing them.

edit: Now that I read this again I realize you were talking about painting over them to repair any breaks, which should work well. At first I was thinking you meant removing the old lines and completely repainting them from scratch.

[dtrumbo]

This is what I bought, but haven't used yet.

[dcketh]

Now you've got me curious as to whether mine works or not, so I'll probably be messing with it tonight.

[bretski]

Now that I read this again I realize you were talking about painting over them to repair any breaks, which should work well..

Correct. My defroster works, but my friend dtrumbo made me go out and look at the grid in the sun. There are a couple of spots that are a little thin. I have some of the circuit paint in my computer parts stash, which is why I'm tempted to try it first.

This is what I bought, but haven't used yet.

That'll werk fer sher...get painting!!!

[Gypsie]

Now I'm curious about Westy's.

Test for continuity (Black lead and ground). If it has continuity then it is either a short or working. OOOOH this is exciting!

[chitwnvw]

Shoot, I've never even tried to use the defroster, you'all are gonna get me motivated!