Tailgate Switch/Glass Wiring Question

[wn]

There's another question on the forum dealing with this problem, but I need more specific help. I put a "new" tailgate on my 75 cherokee and I have it at a glass shop having the wires hooked up. The new tailgate is off an '84 Wagoneer.

The power is to the motor but the switch was bad. I bought a new switch ($37.50)and it still won't work. The technician has checked everything....His problem is he can get the window to work by manually grounding it, but he can't get it to ground by using the toggle switch in front or the key switch in the back. The fuses are good, everything is ready to work, but doesn't.

Is there a schematic of the wiring that anyone has or can someone tell me what he needs to do?

Another question? Is there some type of ground missing from the 75 switch that is needed for the 84 tailgate to operate.

I have already solved the latch differences.... :(

[ July 24, 2001: Message edited by: wn ]

[Bob Barry]

Yes, it is a ground problem; they changed designs in mid-78. The original motor grounded through the case; the new motor grounds through the wiring back to the dash switch. You need a mid-'78 to '85 dash switch, which has the internal provisions for providing that ground, and you'll have to add another terminal to the connector to that switch (it's a five-hole connector, and the early units only used three of the holes; the later switches use the same connector, but with a fourth terminal for the ground). It takes a standard GM Type 56 female terminal (Pep-boys even carries them), that you solder to the end of a ground wire (use a 10-ga, as it's carrying the current for the tailgate motor) and plug into the appropriate hole in the existing connector housing (and, of course, put a ring terminal on the other end and screw it to a good ground).

The tan and brown wires from that dash switch go back to the tailgate and complete the circuit for the tailgate motor.

I did this very conversion on my '78, and it works fine. You just need the different dash switch.

[wn]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Bob Barry:
Yes, it is a ground problem; they changed designs in mid-78. The original motor grounded through the case; the new motor grounds through the wiring back to the dash switch. You need a mid-'78 to '85 dash switch, which has the internal provisions for providing that ground, and you'll have to add another terminal to the connector to that switch (it's a five-hole connector, and the early units only used three of the holes; the later switches use the same connector, but with a fourth terminal for the ground). It takes a standard GM Type 56 female terminal (Pep-boys even carries them), that you solder to the end of a ground wire (use a 10-ga, as it's carrying the current for the tailgate motor) and plug into the appropriate hole in the existing connector housing (and, of course, put a ring terminal on the other end and screw it to a good ground).

The tan and brown wires from that dash switch go back to the tailgate and complete the circuit for the tailgate motor.

I did this very conversion on my '78, and it works fine. You just need the different dash switch.<HR></BLOCKQUOTE>


Fantastic!!! I can get the switch off the same car I got the tailgate off of tomorrow. This is a prime example of how good this website is. The technician knew the ground was the problem, but he just didn't know where. This ought to be added to the technical section dealing with older tailgate swaps to newer tailgates...I called the shop and the tech was very pleased to know where to start fixing the problem.


tongue.gif

[Bob Barry]

Glad I could help. It's pretty obvious where the extra terminal needs to go; in fact, if you have the donor-truck handy, you can pull the old connector with the ground-wire intact by releasing the pins that hold the other connectors in place, and then releasing them from your current truck's connector and sliding them into place on the new one.

Sounds like you're about a half-hour's work away from a working window! smile.gif

Good luck!

[Langdon]

wn,
how did you reconcile the latch difference? I cut the bottom 2 holes off the 'new' latch and had them welded on the 'old'. Just curious...

[Bob Barry]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Langdon:
wn,
how did you reconcile the latch difference? I cut the bottom 2 holes off the 'new' latch and had them welded on the 'old'. Just curious...<HR></BLOCKQUOTE>

I hammered flat the two lower holes in the tailgate sheetmetal, then drilled a new hole and elongated one of the existing holes, using the flathead allen-head screws to form new countersinks in the sheetmetal. That holds it just fine.

[wn]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Langdon:
wn,
how did you reconcile the latch difference? I cut the bottom 2 holes off the 'new' latch and had them welded on the 'old'. Just curious...<HR></BLOCKQUOTE>

O.K. I put an 84 tailgate on a 75 cherokee. The 84 had striker bolts that bolted into the side of the truck for the tailgate to latch to. I unscrewed the striker bolts and took them with me for the new installation. I took detailed measurements of the location of the bolt holes and took this information along. When the new tailgate was installed the old latches on the truck body were removed from the 75. There wass a metal plate where the old latches were and then new holes were drilled for the 3/8" striker bolt. These holes were tapped to have coarse threads (I didn't have this tool; I hired someone to do this)and the new striker bolts were bolted in solid as a rock.

I too had thought about welding, because there was no way I could think of to get a nut on the bolt. Having the holes drilled with threads solved that problem.

The other way to solve this would be to change out the latches on the tailgate but I don't know if one set falls out and the other set would go back in. Actually, if one could do that, that would be the best most secure fit. The problem with resetting the bolts is they have to be in the right spot or they won't match the latch.

I found a switch from an 81 wagoneer today and it has the rear defogger switch attached to it. My 75 doesn't have the defogger so I am going to cut it in two and leave the rear defogger out.

[wn]

[QUOTE]Originally posted by wn:
[QB]


Fantastic!!! I can get the switch off the same car I got the tailgate off of tomorrow.

Guess what! I went to the junk yard that has the car I got the tailgate off of this morning. A young boy was removing it when he said he better ask the owner how much he wanted for it. I told him I would give him $10.00 The owner agreed and then he took it out. Much to my chagrin the switch included the rear defroster switch as well. When I went to pay for the switch, the yard guy wanted $25 because it was 2 switches. I told him I didn't even need the extra switch, because my 75 didn't have a hole for it in the dash. He said "I can't take em apart so it's $25 take it or leave it." I went to another yard and got the same switch for $10.00

[wn]

[QUOTE]Originally posted by wn:
[QB][QUOTE]Originally posted by wn:
[QB]

UPDATE:

The wiring is complete and the rear glass goes up and down per front switch and key switch. Bob Barry's tip was right on target.

Thanks.