Need help with rear window issue

[gotblazers]

Well, I installed the new cable and it didn't get any better w/ 12v. Then I tried adding a thick ground cable from the hinge mounting bolt on the bumper to the body of the truck, not better.

However, with the truck running and pushing higher amps through the wires, the window is quicker with just the cable replacement. I think I'm going to do a relay mod with new power wires to the rear just for the window motor.

When I get to it, I'll post up with results.

Well i'll share my experiences with you from this weekend getting my 1991 C2500 Suburban power rear tailgate to work. For one i dont believe you are supposed to run the ground from the bumper to the body. If i understand correctly you should be running the ground from the motor to the body for the desired results.

What i did that drastically helped. The motor has a ground strap right inside of there that goes around a bolt which is torqued down to give a solid connection for that ground. I used a ring terminal and a piece of wire to put one end of the wire onto the Original ground and then i used a self tapping screw to screw the other end with a ring terminal into the body. Drastic results but still i had the intermittent failure issue from both switches (key And Dash). Since i already had tested the motor earlier that day and realized it was good i went to the only other thing (besides 2 malfunctioning switches) that would cause intermittent failure. Their is a sensor at least inside my suburban tailgate that only completes the circuit when the tailgate hinges are in a closed position. So we cut off those 2 wires and used a wire nut to connect them creating the effect of the gate always being closed as well as always having a solid connection. The gate was closing before but they were so old they werent getting a solid connection and was causing extremely random success of the gates functioning.

Problem solved. Although, I will never get a power tailgate in my life again. I didnt really want this one but it was too good a deal to pass.

 

[clandr1]

Thanks Greg, seems simple enough of a solution to give a shot. What size (gauge) wire did you run for the additional ground?

 

[clandr1]

Well, the ground from the motor to the body didn't help, so I grabbed a can of brake cleaner and hosed the gear where the cable hooks to the regulator. After it dried, I used about 1/2 can of WD40 on everything I could reach inside the tailgate, then held it vertical while I sprayed it down the window tracks on the sides. Seemed to make a noticeable difference, so I'm thinking either the gear was getting crudded up, or the window tracks are in worse shape than originally thought.

At this time I think I can live with it, I'll see how it goes for a couple of months and then reasses.

Thanks for all the information and suggestions everyone.

 

[dieselndixie]

doh, I was hoping you would swap out the electric motor for a manual setup...then I could copy you

Mine has gotten very bad...I know NOTHING about electrical stuff...so I guess I will open that little access panel and start spraying brake cleaner and lube everywhere.

 

[gotblazers]

Thanks Greg, seems simple enough of a solution to give a shot. What size (gauge) wire did you run for the additional ground?

Sorry about not seeing this sooner. I dont recall what gauge i used exactly. If i had to guess i'd say 12 gauge based on memory.

Well, the ground from the motor to the body didn't help
I know this is probably obvious, But did you bring the area on the body down to bare metal with a wirebrush before you ran the wire. And did you make sure to use an O ring crimped (or soldered) on at both ends of the additional wire. A self tapping screw works great to hold down the O ring connector.

, so I grabbed a can of brake cleaner and hosed the gear where the cable hooks to the regulator. After it dried, I used about 1/2 can of WD40 on everything I could reach inside the tailgate, then held it vertical while I sprayed it down the window tracks on the sides. Seemed to make a noticeable difference, so I'm thinking either the gear was getting crudded up, or the window tracks are in worse shape than originally thought.
if you want full access you can use a small holesaw like i did so the area over the bolts that hold the bottom of the window to the linkage (when its rolled all the way down). Once you take those out the glass springs all the way up and i do mean SPRINGS. Hold it carefully as you undo the last bolt or you will be in for a nasty suprise.

At this time I think I can live with it, I'll see how it goes for a couple of months and then reasses.

Thanks for all the information and suggestions everyone.

doh, I was hoping you would swap out the electric motor for a manual setup...then I could copy you

Mine has gotten very bad...I know NOTHING about electrical stuff...so I guess I will open that little access panel and start spraying brake cleaner and lube everywhere.

It is honest to god just a bolt on and off set up. Once you do the holesaw trick as i mentioned above and release the glass and have full access. It probably wont take you more than an hour if stuff is really stuck together. Only downside is your door key wont work on the rear window like it did Originally.

If you can get the window all the way up you dont really need to do the holesaw trick. I just did it because i wanted the linkage to stay down while i had all the advantages of having the window up as far as work room. Just having the window all the way up will give you all the room you need more than likely.

 

[dieselndixie]

When I am sourcing the parts needed, what am I looking for. Is there a "kit" somewhere?

 

[Vetteracerx]

hey chris, one of my fsj buddies drew up a diagram and he posted it over on ifsja. I haven't ever been inside a k5 tailgate, but the window goes up and down just like a wag i assume, so when basically starting from scratch like he did here and running the relays, it should translate fairly easily.

http://www.ifsja.org/forums/vb/showthread.php?t=150627

thanks!!

 

[M14sRock]

Hey guys,

Great thread.

I am having to replace the motor, cable and related parts in my 1990 Jimmy. I want to replace them with good parts, but it seems that some of them are no longer avail OEM (per my mechanic). Where do you recommend I get the right parts? I saw someone mention Classic Parts, so will probably look there first, but any other suggestions would be greatly appreciated.

Thanks!

 

[496truck]

Some items are available at your local Napa like the power motor. So check on that. I remember reading that the side window channels inside the tailgate are still available through GM and come with new rubber in them.

More often than not the regulator assembly can be cleaned and lubed and reused. Along with the slides and channels at the bottom of the glass. Use white lithium grease for that stuff.

That just leaves you finding a new cable. I'd look for a GM one first.

The other main issue is the wiring. I think it was mentioned earlier in this thread on where to look but if you don't have the proper current getting back there (like a loss through corroded splices or connections) and a good ground (as it grounds through the hinges) then replacing/refinishing every mechanical part back there will be for nothing.

 

[M14sRock]

Some items are available at your local Napa like the power motor. So check on that. I remember reading that the side window channels inside the tailgate are still available through GM and come with new rubber in them.

More often than not the regulator assembly can be cleaned and lubed and reused. Along with the slides and channels at the bottom of the glass. Use white lithium grease for that stuff.

That just leaves you finding a new cable. I'd look for a GM one first.

The other main issue is the wiring. I think it was mentioned earlier in this thread on where to look but if you don't have the proper current getting back there (like a loss through corroded splices or connections) and a good ground (as it grounds through the hinges) then replacing/refinishing every mechanical part back there will be for nothing.

Thanks, Brian. I think Napa told my mechanic that the motor was no longer available. I will call them myself today and see what they say.

I appreciate the fast response.

 

[wheels87k5]

If they're still in stock.................

gmpartsdirect.com has the cable for $44.59

wheels

 

[Keitha]

Does the tailgate rgulator have a wound assist spring like the windows do? The last window I fixed, the spring was fairly rusty and really had a ton of internal friction. I soaked the spring in penetrating oil and worked to separate the coils so I could get grease between them. This helped dramaticly.

 

[496truck]

Just finished this write up on the inner workings of the tailgate.

Hopefully it will help anyone looking for this info.

Tailgate Window Break Down