Tailgate window conversion on a K5? Less crank, more speed?

[78 GMC Jimmy]

For a 78 K5, whats involved in changing a manual crank tail gate window over to an electric?

The manual crank is bothersome and very slow.

Swap tailgate and install an up / down electrical switch driven by a key?

Does it need electrical stops, so the window motor doesn't crush and break the window when closing?

Whats the low down?

 

[wazzabie]

Most want to go the other way. electric to manual. lots of problems i read about with the electric.

 

[78 GMC Jimmy]

Thanks for the info.

 

[ZooMad75]

Best thing you can do to make it quicker is fix the rollers and tracks for the regulator. Don’t matter if it’s manual or electric. If the rollers are wiped out and the tracks are crusty it’s gonna be slow either way.

My rebuilt manual regulator would crank up easy.

The biggest issue is the tracks can and will get wet from water getting past the weatherstripping. The tracks trap moisture, get rusty and the rollers no longer have a smooth surface to ride on. So instead of rolling the rollers slide and grind on the rough surface until they have a nice flat spot on them or just get chewed up. That’s what kills them and makes it hard to crank or kills the motor from resistance to moving.

Get replacement rollers and remove the tracks from the glass and clean them up. Use lots of grease in the tracks to lubricate and protect from moisture.

It’s not hard to do. Tedious yes, but not hard. Word to the wise take the regulator out to replace the rollers. Do not put your fingers anywhere near the gearteeth of the regulator. I had one release the spring on me and had my finger been in the wrong spot it would have been done for.

 

[HankScorpio]

I think the motor may be available again. About 2 years ago we tried to get one for a friends suburban and it was "send in your core to have it rebuilt" only. Nothing was available for an outright purchase at the time.

Slow or not I would rather have the manual crank. Both my suburbans are barn door on purpose. My K5 is swapped to a softopper with a truck tailgate to avoid the electric tailgate motor and save some weight.

 

[wazzabie]

The rollers are plastic. I had one roller that was broken in half that cause the window to fall down. I sure would like to replace the rollers with bearings. I currently have the regulator out to replace the rollers. However I found a used regulator at the junk yard that is not rusted. The spring looks to have some tension on it so if it got loose yikes. If it were me I would stay with manual. It falls under the keep it simple.

 

[eodcoduto]

Find an electric tailgate and swap it in, or over. Having an electric window with both the dash and tailgate switches working is great. The rollers will need redone if they haven’t been replaced yet and the felt guides in the tailgate. Clean the grounds up too and you will be happy, and alot of this convenience depends on how you use your vehicle. My tailgate gets uses 3-4 times a week so the electric is a must have.

 

[rampage]

Find an electric tailgate and swap it in, or over. Having an electric window with both the dash and tailgate switches working is great. The rollers will need redone if they haven’t been replaced yet and the felt guides in the tailgate. Clean the grounds up too and you will be happy, and alot of this convenience depends on how you use your vehicle. My tailgate gets uses 3-4 times a week so the electric is a must have.

Can’t really clean the ground since the ground is the motor casing itself. It grounds through the body which are the hinges. If there’s any corrosion under the hinges you’ll get a bad ground and a slow motor. It’s best to run a dedicated heavy gauge wire from the motor case to the frame. I believe there was a TSB that states to do this too.

 

[eodcoduto]

I ran a dedicated ground from the motor to chassis ground and that helped quite a bit.

 

[rampage]

I ran a dedicated ground from the motor to chassis ground and that helped quite a bit.

 

[dyeager535]

The rollers are plastic. I had one roller that was broken in half that cause the window to fall down. I sure would like to replace the rollers with bearings. I currently have the regulator out to replace the rollers.

Power tailgate "improvement".

Edit: Going to put the parts to do this up top. Bearing: On Ebay as 688W4 688ZZW4 618/8ZZ 688 OPEN 8*16*4 mm This translates very closely to a 5/16" ID. IMO close enough. Bolt: Stainless Steel Shoulder Bolts (5/16" - 1/4"-20 x 5/16") 1046-010-0012 @ albanycountyfasteners.com Spacer: 3/8"...

ck5.com

 

[78 GMC Jimmy]

I used the tailgate all the time, so the hand crank is a pain. The hinge on the crank handle keeps breaking.

Also, anyone got any heater controls available? Non A/C.

 

[Barrman]

The best description I have ever seen for the manual crank is this:

Designed by an idiot who then consulted a committee of morons.

Yet, I have kept the manual system because window up or down. I can always pull the cover and make the window go where I want it to be. I don’t know if a frozen motor can be put up or down by hand and kept there.

But, if actual new motors with quality in them are really available. Going that way might be better because the manual crank just has junk “new” parts available in my experience. Maybe buy 2 motors and keep a spare in the truck if traveling.

 

[Big Ray]

Do a relay mod. Works for headlights, cabin windows, and anything else that needs a bump of electrons.

 

[rampage]

Yet, I have kept the manual system because window up or down. I can always pull the cover and make the window go where I want it to be. I don’t know if a frozen motor can be put up or down by hand and kept there.

You can raise and lower an electric window in a pinch. Just disconnect the cable from the motor that goes to the regulator and insert it into a drill.

 

[Barrman]

Good to know. I have an entire power window tail gate just in case I ever really, really get mad at the stupid manual hand crank mess.

 

[78 GMC Jimmy]

I have a divider right behind the front seats. Rear seats are folded forward. So the ONLY real cargo area is in the back, which can be accessed thought the tailgate. So its kind of a pain to use the cargo area if you run errands in town and have to lower/raise the window half a dozen times in town and then a few times at home.

Maybe an electric window would be easier. In a perfect world I would have a lift gate or a rear widow that opened the same way a lift gate does. Like the later model Tahoes / Suburbans. Is it possible to modify the rig to have rear barn doors?

 

[rampage]

Is it possible to modify the rig to have rear barn doors?

Of course it’s possible, but how much time and money do you want to throw at it? Are you asking if you can put ‘Burb doors on a Blazer? IIRC there was a discussion about this eons ago that detailed how the ‘Burb rear end is different than a Blazer and it wouldn’t work without a lot of fab work.

There use to be a prominent member on here by the name of Grim Reaper who had a truck by the name of Dollar, because that’s how much he paid for it. Don’t know why we can’t do a search using his username any more, it’s not even in the member list - like he never existed. Anyways, he built a split tailgate out of square tube. Don’t know if you have access to these articles showing it since you aren’t a paid member but these are the only pics I could find:

https://ck5.com/forums/resources/a-guide-to-packing-for-the-trail.28/


Scroll down to the bottom of this one for a little description:

https://ck5.com/forums/resources/specialty-tops-fasttrac-soft-top.65/