I guess I give up on the windows

[Snoots]

Do you happen to know where these ground connections can be found? I'm assuming there's wires running through the rubber tubing that goes from the door, into the cab. But the ground wire has to terminate somewhere.

They do not have a ground wire. GM grounds them through the hinge pillar.

 

[squaredeal91]

They do not have a ground wire. GM grounds them through the hinge pillar.

That would Explain some of the symptoms I'm having lol

 

[PhotonFanatic]

I feel your pain. Same for me. New rubber and motors.
Driver side fine, passenger side is the issue. Talked to buddy last night, he has the same issue on his '84, mine's an '83.

My driver works ok (not great) and the passenger side needs help from a hand most of the time. Looks like more electrical diagnosis is needed. This truck will force me to get really good at that.

I think there's a pretty bad voltage drop when you press the switch. Some other posts have said it can go down to 6 or 7 volts. Ensuring it never did that may solve the problem. It may be fixed if you just force the voltage back up to 12 or 14v.

Here's a thing on Amazon, looks like it may be right. Looks like you buy your own housing though:

https://www.amazon.com/dp/B08PV5YY55/

Here's a video of a different one:

xc_hide_links_from_guests_guests_error_hide_media

 

[Redfish]

@PhotonFanatic I replaced the passenger side window motor a few months ago. At the same time I replaced all the window felt/weatherstripping.

Like you, I was extremely disappointed. The d***ed thing barely worked, still needed to be helped by hand. After a few drives, some exposure to heat/sun and more window actuation it now works just fine. We did the weather stripping on both sides and at first it definitely slowed things down. But it did eventually loosen up.

I can tell you that my Mom bought a 1984 Blazer brand new with power windows and they were never fast from day one. My windows in my '87 work exactly the way I remember from 1984. They are not "fast" but they do move. You can hear if the motor is turning like it is supposed to. If it's in a bind, it will sound like it's in a bind.

 

[PhotonFanatic]

@PhotonFanatic I replaced the passenger side window motor a few months ago. At the same time I replaced all the window felt/weatherstripping.

Like you, I was extremely disappointed. The d***ed thing barely worked, still needed to be helped by hand. After a few drives, some exposure to heat/sun and more window actuation it now works just fine. We did the weather stripping on both sides and at first it definitely slowed things down. But it did eventually loosen up.

I can tell you that my Mom bought a 1984 Blazer brand new with power windows and they were never fast from day one. My windows in my '87 work exactly the way I remember from 1984. They are not "fast" but they do move. You can hear if the motor is turning like it is supposed to. If it's in a bind, it will sound like it's in a bind.

Yeah it's pretty disappointing when you spend time and money to fix it, and barely see any improvement.

The problem seems to be that there's more than one problem.

I replaced the old motor because it was dead, but the new one seems like a slug. I guess it's not, and it's just having to deal with some other issue so it can barely do it's job. One way or another I'll make em go at least as fast as when they're new. They may also be a bit weak, as electric motors go. The fact that they were always a bit slow may indicate that. It's a problem across nearly all GM vehicles of that era. There's a ton of information on it on F-body, and G-body forums. That's where I got the voltage booster idea.

Normally you try running thicker wire, but there's a limit to that, and aren't the wires like 10 gauge already? How much thicker can it get?

I think someone around here knows how many amps these window motors pull. It was pretty high, like 15 or 20 amps IIRC.

 

[GTX63]

A quick test to see if the issue may be electrical is to rev up the engine and see if the window speed increases at all.

 

[TotalyHucked]

Unfortunately, the only "Fix" is a kit from Nu-Relics. The factory stuff was fine when new but all the OE replacement stuff now sucks.

I went through this same thing on my '85. It already had replacement motors in it when I bought it. I lubed everything really good and they worked "OK" for the first couple years. Then they started to slow a bit and I had to rev it up to speed them up. So I installed the LMC relay kit. That helped on the pass side but did nothing at all on the driver's side. Then they just randomly completely died one day. One up, one down, the night before I was supposed to leave for a show.

It pissed me off so bad the truck didn't get touched for a couple months and I finally got out the CC and ordered up the Nu-Relics kit. Super easy install, took an afternoon and now they work like a modern car. I know $400 sucks to spend but if there's anything on these trucks that's worth it, it's that. You won't regret it.

 

[CountKrunk]

I was about to ask if anyone had feedback on the kit from nu relic so thanks.

Anyone else with any nu relic stories? I recently picked up an 84 c20 3+3 and this sort of content is the exact reason why i joined this forum so thanks!

Unfortunately, the only "Fix" is a kit from Nu-Relics. The factory stuff was fine when new but all the OE replacement stuff now sucks.

I went through this same thing on my '85. It already had replacement motors in it when I bought it. I lubed everything really good and they worked "OK" for the first couple years. Then they started to slow a bit and I had to rev it up to speed them up. So I installed the LMC relay kit. That helped on the pass side but did nothing at all on the driver's side. Then they just randomly completely died one day. One up, one down, the night before I was supposed to leave for a show.

It pissed me off so bad the truck didn't get touched for a couple months and I finally got out the CC and ordered up the Nu-Relics kit. Super easy install, took an afternoon and now they work like a modern car. I know $400 sucks to spend but if there's anything on these trucks that's worth it, it's that. You won't regret it.

 

[TotalyHucked]

I was about to ask if anyone had feedback on the kit from nu relic so thanks.

Anyone else with any nu relic stories? I recently picked up an 84 c20 3+3 and this sort of content is the exact reason why i joined this forum so thanks!

I absolutely love mine. Like I said above, install was super simple, I'd rate it about a 3/10. Very happy with them, had them over a year now and they still work flawlessly. Even with the truck not running, they run up and down super fast. I've been trying to convince @Old77 into some, can't remember if he's used them yet. I don't have experience putting a rear kit in but if it's like the front, it'll be cake.

 

[wingman50]

Installed this harness on my ‘81. Maybe not as fast as a new truck but very close. LMC Truck

Heavy-Duty Power Window Harness​

You must be registered for see images attach

 

[PhotonFanatic]

Installed this harness on my ‘81. Maybe not as fast as a new truck but very close. LMC Truck

Heavy-Duty Power Window Harness​

Wish I knew about that before I did mine! I just bought relays and did it all myself. Took awhile to plan everything out. My doors are a little faster than they were. They went from painfully slow to just slow.

I'll keep the nu relics in mind if I start driving the truck more.

 

[82BBC20]

I’ve redone both doors on my 82 including replacing vent glass assemblies, when I first started the windows would only go up about 3/4 then stop, I kept everything loose in the door working the glass up & down making small tweaks as I tightened & loosened everything until I got both sides working pretty good & seating all the way up in the run channel. Also used a lot of silicone spray to lubricate the glass channels.

 

[Scribbles]

I've done everything you can do to fix the slow power windows in my 87. All of the door rubber has been replaced. All the rubber has been lubed with Syl Glide. There's new AcDeclo brand motors and regulators. New switches. The relay mod is installed so they draw directly from the battery. The battery is a new deep cycle. Most of the truck's grounds have been replaced recently. The windows are still slow. To the point that sometimes they don't actually want to roll up. As though no work was done at all, and everything is still all original.

I do have to mention one last thing I haven't done, so maybe "everything" wasn't the right word. But I don't think I'd attempt this one. Not unless I had both doors off the truck and they were being totally rebuilt... You might be able to bend those tracks inside the doors, that the glass slides in.

I'm referring to the metal tracks that the felt/rubber sits inside of. If that shifted even just a little, it could make your windows run slow or get stuck sometimes. But how would know know exactly how to bend them back? It may be a difficult job to get them bent exactly right. Such that I'd really like to have both doors off the truck, then you could test the speed every step of the way.

So I was wondering if anyone ever made them go fast. Or at least, made them work at the factory speeds. I know these windows were never "fast" but they were adequate when they were new. Maybe to solve the problem for good, you have to buy those upgraded motors for the windows that are made to run extra quick. But IIRC they're $250 each.

I had that problem on my 67 Elcamino. I ran a separate ground from the kick panel to the motor and that fixed it. After that i just moved it to go with all the other wiring through the door boot.

 

[PhotonFanatic]

I had that problem on my 67 Elcamino. I ran a separate ground from the kick panel to the motor and that fixed it. After that i just moved it to go with all the other wiring through the door boot.

Was it a pain to run it through the door boot? Maybe it would work to just run the new ground to the door itself. I should have thought of that when I had the door panel off

 

[mibars]

GM motors have 2 hots going to the motor (up and down) and need a ground to operate.

That's not true at least for the 1990. It's a regular system with both poles connected to a ground and a positive switched to either side to make it go up or down. The issue is that both power and a ground pass trough the switches and lengths of wire before reaching the motor.

I'd try running the motor straight from 12V DC power source, a battery or a minimum 10 A power supply, if the window is quick to operate then it's an electrical issue.