Pwr rear window - input from those who've messed with relay etc.?

[ikavo]

OK folks,

Everything works fine except for the black box in the picture at the top of this thread. Not the circuit breaker, but the thing to its left. I think all that thing actually does, per the great diagram from Bigmookied, is send power to the dash switch.

So...the question is...why do I need it? Can I feed power directly from the circuit breaker to the dash switch? It seems plausible, since I don't think this item is on Bigmookied's diagram.

Everything else in the system works great now, though it wasn't always that way. Turns out I DID have some inconsistent grounding that made all this that much harder to test.

If anyone kons what the black box thing is, and whether it's got to be there, please let me know. It takes a feed from the circuit breaker (the feed that doesn't go to the tailgate key switch), and sends it into the cabin. I put power into the wire from the mystery box, and by activating the dash switch, it sent power to 83B and 83C to lift/lower the window. The mysterious box also has a narrow guage dark brownish wire....not sure what that does.

Any thoughts on how necessary this is?

Thanks

K

[bigmookied]

I do not beleive it is necessary, but I also do not see it on any wiring diagram.

Trace it to a source, then let's figure out what it does.

[ikavo]

Ok folks, to keep this useful for the next guy with my problem, here's some more information:

1. The ground was intermittant. I decided I didn't need the safety, so I ran a 'real' ground to the frame. Now my real switch (the tailgate key switch) lifts and lowers the glass.

2. I'm nervous about just cutting out the mystery box, which could be a relay of some kind that only allows power to flow when the dash switch is partially depressed, so that the switch doesn't get toasted. I think a better solution, though, is to run a new wire to the key switch, and use the two wires that come off it (83 B and 83C) to engage relays that receive their 'main' power off the circuit breaker.

Basically, this would involve running a third and fourth wire off the circuit breaker, so that 1 wire would go to power the tailgate switch as indicated in the diagram, one wire would go to the dash switch, just like in the diagram, and a third and fourth wire would be the main power for two relays that would send power to put the glass up and down.

In the diagram, these relays would be between the dash switch and the 3 way connector.

I think standard 30 amp Bosch type relays would work great. Does anyone think this wouldn't work? It might be overkill, but it should be safer (less power running through the dash switch) and it should decrease resistance, so the window flies up and down.

Let me know if anyone thinks I'm crazy,

Thanks alot for all the help and comments too - especailly to Bigmookied.

Karsten.

[bigmookied]

Karsten,

Circuit Breaker is rated at 30 amps, as is the switch. So as long as you are running the 10 gauge wire there should not be a problem with the system, as the circuit breaker will shut down if there is overload. So running relays would probably be way overkill.

I also advise against the safety switch removal. The window needs the upper channels to run correctly and hit the top to stop travel, so it needs the tailgate to be closed. Also, where the switch is located on my dash I have hit it a few times and the window shot out at my garage door (I did not break it, but it scared the crap outta me).

No need for thanks, I am just trying to pay back for all I have learned from everyone here.

Armando

[ikavo]

Bigmookied and everyone else:

First, this forum is awesome. I'm grateful to everyone, and especially to Bigmookied, because my rear window f l i e s up and down.

I ended up going with the relays, since there was space to mount them on the firewall, they're cheap, and troubleshooting will probably be easier.

I used NAPA off the rack ones made for 18 wheeler lighting.

Anyway, that should protect the switch, even it is rated for the full load. That's good in my books, because I don't want to pull the dash to replace the switch.

Thanks again,

K

[Afireinside2285]

I have a 72 Travelall 1110 and it has the exact same wiring as your photo.Mine goes up and down at a medium pace but the tailgate switch does nothing. I'm thinking when it warms up some to do what you did.
Do you have part numbers and how you ran the relays.I like the idea thanks

[bigmookied]

It should go like the attached diagram, which is morphed from the headlight relay diagram (http://www.danielsternlighting.com/t...ys/relays.html)

Remember to use the 10 Ga. Wire for all hot lines carrying high Amps. You may be able to get away with using the old wire if it is still flexible, but I would change it out anyway.

Wire in the dash switch from an accessory switch on the ignition switch, then run from the up and down poles to the relays. these can use 12 or 14 gauge wire to make it simple.

Use standard bosch type relays found at your local autoparts store or Walmart. They are black plastic with the mounting tab molded on.

If you are having problems with the key switch on the tailgate, make sure the plug is connected and you have the proper key. My key will turn in the hole, but not enough to engage the switch.

Let me know if you need more details.

[ikavo]

Wow, Bigmookied diagrammed it exactly like I wired it, except that I powered the dash switch off the circuit breaker AND ran the relays off it. That saves figuring out where to tap into power.

The relays are NAPA relay No. 192, and it's rated at 40 amps so it has some headroom.

Finally, I created my own connectors by soldering female spade connectors to short lengths of wire that I then soldered and crimp butt connected to existing wiring (leads to dash switch, and wires to the motor's up and down).

The two new connections to the circuit breaker were soldered and crimped in rings, and the grounds for the relays were too. I tucked those ground rings behind the relays, and used the relay attaching screw (the one that holds it in place) as the grounding mechanism through the firewall.

K

[ikavo]

Oh, and PM me if you run into issues...I've gone through the entire circuit now, so I can probably help you over the phone if necessary.

Finally, on the rear switch not working, make sure you have continuity on the wire 83A in Bigmookied's diagram (and power to it from the circuit breaker). I suspect that's your culprit, not the rear switch itself. Who knows though...they ARE old trucks

[Afireinside2285]

Thaks a ton thats great.I probably won't mess with it till it warms up,I dont need the window down right now but thanks a ton.