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Slow power windows - upgrade to LMC HD harness?

RSAP

RSAP

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ive taken apart my power windows on 85 blazer, cleaned the regulator, the sash track, the wheels. And even replaced the motors. Still slow rolling up and down. Any feedback on going with the LMC heavy duty wire harness, which draws power directly from battery? Not a fan of cutting factory wires...

Kind of seems like a common theme with low power.. headlights seem ok. But the brights barely light up..

Thx
 
Someone here did a wiring conversion of their own using relays to get 100% battery juice to the window motors. You could try a search, or hope someone with a better memory than me remembers the thread and can post a link. I recall it worked pretty good.
 
We installed the LMC harness in an 87 at work along with new regulators and motors...it was noticeably faster rolling up the windows.
 
Installed the harness and one new motor in drivers door. The drivers door is noticeably faster than passenger door. Sooo I am going to get a new passenger door motor when I get time. So yes the harness helps.
 
I saw it installed on one of the truck shows (truck U maybe?) on motor trend channel recently they did a review and it was much quicker than original. They noted it was pretty easy to install and all the necessary parts were included for a clean install (hiding wires)
 
I did my own relay system and the windows go up/down much quicker now. I just recently ran across the wiring schematic I used.
 
Spraying some silicon lube in the window channel helps significantly. I hit mine a couple times a year. After seeing this link, I may go for the wiring upgrade, doubling the speed would cut the aggravation of waiting 10 extra seconds to spit ma chaw juice out when I’m wheeling.
 
If I make it to my container over the weekend and can remember where I seen it I will post it up.
 
I did a relay setup on a friend's '90 about 5 years ago. When I installed all new felts and regulators that he got from LMC, the windows wouldn't really move. Using silicone lube helped get them moving almost like before. Still slow. The relays made then work.
I followed the schematic that I found somewhere on here.
I am now working on doing the same to my '90 because I wasn't really impressed with the headlight harness that my buddy got from LMC, even though it worked fine. From what I understand, the window harness is sold per window, so it adds up, however I may be wrong. And this way, I get to design it how I want, even though I am going slow due to trying to keep things from stacking up at the battery terminal, and routing the wires nicely through the dash area.
I hope that @4X4HIGH can help with the schematic, cuz don't know how to post a drawing.
 
I had a bad experience with this harness in my K30, although I did not install it myself, my buddy did. Could never get it to function properly. Ended up buying all new regulators and wiring from NU-Relic and I'm super happy with their setup. Pretty sure you can just use their wiring. It is made in the USA, where everything I was getting from LMC came from Taiwan or China. I will use Nu-Relic in the Jimmy back door when it is time. Just my $.02
 
This is on the list of 'repairgrades', AKA 'MAW' for my '79 - that wiring diagram is perfect, it'll save me a few minutes thinkin'.

The final project for the power windows looks like so;

  • New power feed to window, replace old feed, use high strand count 'arcticflex' wire in 10 gauge
  • Terminate in fused position in fuse block or distribution block
  • New ground feed to window, replace old feed, use high strand count wire in 10 gauge
  • Terminate on ground stud or distribution block with wire path to batt ground
  • Assemble wiring as per diagram, use heat shrink terminals and/or splices
  • Hang relays properly
  • Dielectric grease on all terminal connections
  • Replace switches while in the door
  • Lubricate all tracks and gears
  • Replace any damaged or missing trim

I'm a little concerned at 14 gauge being specified for the ground in the above - ground should match power, it's a circuit. 14 is perfectly cromulent for signal wiring, but the motor feeds should be beefy. Out at the far end, having a good power tap and ground tap is a necessity. I'm fairly certain I'm going to end up with a Bluesea ST-Blade or two in the cab as well as underhood ( The fuse panel of choice for cop cars and ambulances ).

I mentioned high strand count copper wire - I've ran into multiple instances of 'normal' wire getting destroyed by a flex joint such as a door transition. LMC's got a pin based setup, which is fine for removable doors (keep it greasy and clean and it should last for a good long while). The higher strand count wire is my shop's go-to for any power harness or signalling wire that is going to be able to flex or wiggle at all, it provides another level of durability. The Arcticflex brand is the locally available one. The wire ends up being a lot 'whippier' and more flexible than normal stuff. The sheathing / coating is also squishier and more flexible. It's slightly softer and less abrasion resistant, but grommets are good for you anyway.

Anyone have pictures or diagrams of a good place to physically mount the relays inside the doors?
 
I don't have a photo, but I used the two ⅜ bolts under the pull-handle. You can put one on each.
 
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