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ike73 03-13-2004 12:30 PM

Manual to Electric Tailgate Wiring?
I'm replacing my rotten tailgate on my '76 Blazer. The new tailgate is electric and my old one was manual. Having never been known for my wiring, I was hoping some of you could walk me through it? I am not sure where to wire it up to on the fuse box. I did fugure out how to raise and lower it with a battery, so I know it works fine, I just don't want to burn up the motor or start any fires, ya know?!! Thanks for any input you guys can help me with!!

gregmgm 03-13-2004 03:05 PM

Re: Manual to Electric Tailgate Wiring?
I've done quite a bit of wiring, (but not a pro) This is my opinion. (My 78 PU is similar wiring wise) Run a heavy wire from the battery (fused) to a DPDT switch, middle terminal. Personally, I would avoid tapping off the fuse block, but that's my preference. The switch should be off in the middle position, and momentary in either of the two ON positions. Run 2 wires to the tailgate, and splice to the two power leads for the window motor. You might have to run a ground wire for the tailgate as well. Now hook the wires to the switch so up on the switch is up on the window etc. On my truck, its easier to run the wires (front to back) along the frame, supported by ties, and protected with rubber tubing where it rubs metal. Just be sure to protect the wires from anything that could damage them, and short them out, or blow the fuse. Also, You could use a metal "L" or bracket under the dash to mount the switch, using existing screw holes. My truck has switches, and airbag controller crap under the dash, and I didnt have to drill any new holes. (Airbags for camper- not lowering) Greg

ike73 03-13-2004 07:19 PM

Re: Manual to Electric Tailgate Wiring?

No don't appologize for the long post. I would MUCH rather have someone long-winded than a three word reply!!! I didn't even think about running it right from the battery. I just assumed (yeah I know) that it had to be fused like everyting else, but I suppose an inline fule would do the same huh?

I now have the tailgate mounted and can "roll" it up and down with a battery. My only real concern is that there are four wires coming out of the 'gate. When I hook the negative up to the black wire, either a blue or white rolls the window up or down. There is a third red wire that doesn't seem to do anything, any idea what that is for? I would think that if it were for the key to operate the window it would have a pair of wires?

Anyways, I assume (here I go again) that the black should be grounded to the body and the blue & white would be taken forward to the swich... so whouldn't I have a three terminal swich? One coming in from the battery and two for the swich? Thanks for the advice, I REALLY appreciate it!!!

gregmgm 03-13-2004 08:13 PM

Re: Manual to Electric Tailgate Wiring?
OK then- long posts it is!! An inline fuse is fine for the tailgate circuit. You could even use one of the new style blade fuse holder, with a rubber cap- kinda nice if you ask me. You'll have to use a ring terminal for the battery end, which should have heat shrink to seal it. As a matter of fact, use heat shrink for any connection in the engine compartment. You probably are correct on the wires for up and down, but I'm not sure about the red wire. Also I forgot about the keyed switch in back. Try putting power on the red wire, and turning the key switch in back. Maybe the switch is wired to the motor that way. Check to see if there's wires from the key switch to the window motor. Hopefully there will be. I would say for sure the black one should be grounded. Concerning the new switch for up front- the one I was thinking of should be a 3 position with 3 or 6 terminals. The middle position will be off, and up or down in either of the other positions. Use the middle term for power, and the other 2 terms for up or down, but if its a 6 term switch, make sure to use the terms on one side or another.(All in a row)
One more thing- (geeeeees quit already) If the outside key switch isnt wired up or doesnt work, that's a whole different explanation to post. I dont mind at all explaining this stuff, so if you have any more questions, dont hesitate to ask. Greg

muddfred 03-13-2004 09:25 PM

Re: Manual to Electric Tailgate Wiring?
I did this conversion on my 79 Jimmy. You need a momentary DPDT switch for the dash and a power wire to the switch and the then two wires from the switch to the tailgate. The four wires from the tailgate are two for the switch, up and down, one for a ground and the other is for a hot wire to the key switch in the tailgate. If you don't have the key you don't need the hot to the tailgate. If you need a key switch they are about $35 from the dealer.

BE VERY CAREFUL WITH THE SPRINGS ON THE TAILGATE WHEN YOU REMOVE IT . It is easier to cut them and forget about them. It helps build up yoyr arms when closing the tailgate.

ike73 03-15-2004 07:39 PM

Re: Manual to Electric Tailgate Wiring?
Sorry for the delay in getting back to you guys, I got caught up in Honey-DUE's!! I could not find a momentary switch that was three way for some reason, so I just got a standard 3-way switch. Maybe at a later date I will find one, but for now that will have to work. I did get it wired up outside of the vehicle just to make sure it worked. To my surprise it did just great!! I can't tell you guys how much I appreciate your help!! Thanks so much!!

I do have one last question before I finish the job though. The wire I currently have to use is 14 awg., the wire from the tailgate appears to be 12 awg. (it is just slightly larger than my 14) and the largest inline fuse I could find (which is 30 amp) only came in 14 awg. Will that be alright? The window seemed to work just fine, but should I go get 12 awg. and/or keep looking for a larger fuse? Thanks again!!!

gregmgm 03-15-2004 10:29 PM

Re: Manual to Electric Tailgate Wiring?
Hey- - the honey do's have priority before our own projects!!! I found a switch like that at my local marine store, but they're expensive. I dont know about Pep Boys or whatever auto parts store, I didnt look. Cool that it worked out for you.
As far as the wire gauge-if you can, use thicker wiring. It may not make any difference at all, but I would say it might be safer with the heavier wire. I usually go overkill on my wiring jobs (gauge wise) but then, I dont worry at all about the circuits being overloaded. If you look around more, you should be able to find a heavier gauge fuse wire, but the 30 amp fuse itself should be fine. Keep whatever wiring and fuse holder you already bought for the 437,411 wiring projects you might come up with in the future. Greg
PS You can order heavy gauge fuse holders, switches, etc from places like Wire Works or Watsons Street Works (check their websites) ahead of time to have for future projects. Always nice to have on hand.

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