K5 rear window motor - Replacement are garbage - Alternative solution

[stuman]

The problem is likely in the mechanism itself, even though it seems to move easily with the drill. I gave up and converted to a manual crank assembly after twisting off a new cable...even though the window moved readily with a small drill.

 

[1987 GMC Jimmy]

The switch in the cab is more a replace it item than a rebuild from what I recall. Someone at some point linked this to me as a replacement but I am not certain to be fair because I am still contemplating whether to use an inside switch or not.

https://www.amazon.com/dp/B004GIGUA...olid=27MZ7VYAGDIIP&psc=0&ref_=lv_ov_lig_dp_it

That might have been me. I bought that one, too, and it’s still in the bag. My problem with the original switch was the springs. I may just save it and do the Philmore switch.

 

[rpcraft]

Are those drills "red" by chance? You would be putting the "red" into "redneck" if so...

I'll probably buy one of those cheap HF pieces of trash to toss in there, that or one of the ones with a yellow casing. It's still cheaper than a manual regulator and then the roller mechanism (unless I can find one in the wrecking yard).

 

[BiggDeano]

You need to wire in two relays one for up and one for down so the motor gets full battery voltage. Look at the setup LMC has for the front windows. It’s an easy cheap setup have the switches activate the relay.

 

[rpcraft]

Yeah I know what to do believe it or not, lol. I just currently have it hot wired direct with the tailgate switch so I can close it up and lock it and store a few things in it because I have the entire harness out of the truck in order to repair some rust and coat the tub once that is done. Going to have an additional rear mounted battery as well so I will probably power it from that instead of the drivetrain power.

 

[Snoots]

Alakazam!

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[rpcraft]

Long story short the problem was more with the side rails that guide the window. Once I replaced them thing got so much better. I have gaskets for the tailgate and top which will help as well. Huge difference in the end. I did end up picking up an OEM motor and regulator so I have a spare of each now.

 

[Snoots]

Glad to hear you got it going. Spare parts are good.

 

[1987 GMC Jimmy]

Okay, so I made a crimptastic harness adapter to avoid cutting the factory harness off so I could try the Philmore switch I bought. My circuit breaker’s good, and I’m getting power to the pink, across the switch, and down into the harness but no window action. It’ll want to go up when I turn the key switch but not down. I’m gonna fiddle with the safety switch and probe voltage towards the rear.

 

[gmachinz]

It’s usually not a voltage problem-those motors are an old design where they ground to the chassis through the motor housing/body/bolts. Check your rear frame ground really well for rust, frays or breaks.

 

[rpcraft]

It’s usually not a voltage problem-those motors are an old design where they ground to the chassis through the motor housing/body/bolts. Check your rear frame ground really well for rust, frays or breaks.

Real good feedback. Between the body ground issues that the 80's GM's had and the fact that the the window tracks all wear out from hard/cracked and/r missing weather stripping it's ver seldom an actual motor issue. If you measure the load on your motor if it is having a really high amp rating then it's either a fouled wire or ground, or the motor is doing more work than it is supposed to