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'90 XJ Power Window improvement

tjmotter

NAXJA Forum User
NAXJA Member
Location
Texas
My power windows sucked. The Passenger side was the worst and not only would it not have enough "oomph" to fully close the window but I would have to fiddle with the button a dozen times to "help" it work through some dead spots. Most posts recommend changing the window motor but I tried something different and here is how it works now:


https://youtu.be/2UrLJr04QOw


Pretty much like brand new again. The "fix" was to apply the "Greg Smith Door Lock" fix to the windows. https://www.naxja.org/forum/showthread.php?t=1874&page=15


The issue I found was twofold. 1) The ground plane is undersized and 2) the switches simply can't pass the power through to the window as well as they could when they were new. To address this, I added two weather proof relays to the circuit:


https://www.amazon.com/PACK-AMP-Wat...j1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ


and installed matching weather pack connectors to them so that they were easily removable (they will plug into the existing connectors):
https://www.summitracing.com/parts/aaf-all76266



Since all the switch does is connect one wire to ground and the other to power, what this "fix" essentially does is to reduce the load on the switch so that it simply sends a "trigger" signal to the relays. The circuit is pretty much identical to the Greg Smith writeup for locks but rather than use the supplied ground, I tied the relay ground to the chassis by grinding the paint away from the existing holes for the manual crank window option and then used them as the mounting point for the relay as well as the window ground. I then used the existing power wire (connected to the switch) and tapped into it to also provide the power source for the relays.


On my first attempt, I simply used the relays to pull the ground from the chassis but continued to use the power coming from the switch to provide the +12V for the motor. That worked MUCH better but it was still a bit slow. Next, I stripped some insulation from the power wire that feeds the switch and connected my relay into that and the result is what you see in the video.


Only my fronts were bad so I had to do this twice but I am really happy with the results.


If anyone needs more detail on how to do this, send me a PM.


HTH
Todd
 
Last edited:
Wow! That's an impressive video.

I have to do my door locks on my '93 as they just failed annual safety inspection for being too stiff to operate. While I have the door panels off for lock cleaning I will take a look at the lock and window wiring improvement.
If I hadn't seen your video I wouldn't have bothered to do the windows.
 
Copied from an update I provided to the Greg Smith Lock thread for anyone looking for more details.



Here is how I wire it for both the door locks as well as the windows.



I found it MUCH easier to just tap into the wires in the door rather than directly connecting the wires to the battery. The issue is that you need a set in each door and squeezing new wires through that loom is a bit of a PITA.

For the ground, just solder the two wires together and crimp or solder a ring connector like the one in the link below. Use an appropriately sized pair of bolts/nuts and connect the relays and this ground to one of the holes where the manual crank would sit. For door locks, simply mount it to the frame somewhere.

https://www.belmetric.com/index.php?main_page=product_info&products_id=1349& cPath=19_164_202_2390&msclkid=e3bf4dd78f771d82498b 12688f9f32fc&utm_source=bing&utm_medium=cpc&utm_ca mpaign=%2A%2ALP%20Shopping%20US%20-%20Electrical&utm_term=4584001421561164&utm_conten t=1349%20%7C%20E901%20-%20Uninsulated%20Ring%20Terminal%20%7C%20%241.65&z enid=do6fmatve9mjn8hhdv198au805


For power to the windows, I simply grafted the power wire to the Violet/White strip wire going to the switch. This provides 12V when the ignition is on and is protected on the fuse panel. The power going to this wire is more than enough for the windows. For power to the door locks, you can route the wire to the battery since you will be placing the relays behind the kickplate.

To tap into an existing cable, something like this works best:
https://www.walmart.com/ip/30-Pairs-...7c49365bf9e27e

The inputs will be the wires coming from the existing door switch.

The outputs will go to the window motor or the lock depending on which you are installing.

Unless you have a meter and want to scope the power flow before you start there isn't an easy way to determine the input/output wiring. There are only 2 possible combinations so the easiest way I have found is to wire the inputs permanently (coming from the switch) first. Next, connect the outputs temporarily and test the system. If you press the lock button down and it opens, reverse the output wires. Same with the window circuit. If you press down and the window goes up, reverse the output wires and it should work properly.

The "theory of operation" is pretty simple.

Using a 5 post relay, the default position will connect Pin 30 to Pin 87a. When power is applied to pin 86 of either relay, it will switch that relay so that Pin 30 connects to Pin 87.

The pins marked 85 and 86 are the two sides of an electromagnet. Since pin 85 is connected to ground, simply applying power to pin 86 (when you press the door switch), will turn that relay on. The door switch is designed so that when you press "down", one of the output wires connects to ground and the other connect to 12V. When you add these two relays, the wire that goes to ground stays "low" which means Pin 30 is connected to Pin 87a which is already tied to ground so that relay will stay off but the relay will provide a ground path for the motor. The wire that connects to 12V turns the second relay on which connects the motor directly to the 12V power line that feeds the switch. When you press "up", the order is reversed so the first relay goes to 12V and the second relay stays connected to ground.


HTH
Todd
 
Wow! That's an impressive video.

I have to do my door locks on my '93 as they just failed annual safety inspection for being too stiff to operate. While I have the door panels off for lock cleaning I will take a look at the lock and window wiring improvement.
If I hadn't seen your video I wouldn't have bothered to do the windows.

Might be worth shooting some silicone spray into the tracks where the windows ride, and some white lithium into the "worm drive" that the motor spins...
 
This is a terrific repair and should have been an engineering change but you did it ..I would like to save this info to use shortly ... I am new here and dont know all the ins and outs
My windows have exactly them same issue and you have the perfect fix.
:yelclap::star:
 
Yupp I've fixed many windows with some lube. The ole quote "lube her if ya love her" comes to mind bahaha

Sent from my SM-G950U using Tapatalk
 
Yep ,,, you guys get it
by upppping the accumulative wire size you use OHM s law to decrease resistance in total wire size allowing higher voltage giving the motor more poop.:clap:
Im new to this forum and havent figured out all the how to do stuff.
 
Yupp I've fixed many windows with some lube. The ole quote "lube her if ya love her" comes to mind bahaha

Sent from my SM-G950U using Tapatalk


I should add that I had already removed both front regulators, cleaned them and lubed them but my windows still sucked. As I noted below, the passenger side required me to hold the window with my hands and push up while operating the switch.


Lube will only get you so far when the copper contacts in the switch corrode but this fix resolves that by moving the current flow to the relays. As "Dceramic" notes, this approach by-passes the growing electrical resistance in the switch/contacts and simply routes the power through a different path.


HTH
Todd
 
Yea ,, lube is a good start but my pass .side motor is now dead. 1st I had no power in the pass door for the window.... The power switch on the driver door will sw. off or on BUT the wire from the switch supply's power to 3 doors which is connected in the wire harness under your driver feet.... Thats ok but when it gets wet over and over it ends up looking like a battery connection green corrosion then ... no power to 2 windows... so that repaired attention to the pass door window and the motor said ,,, Im done pooof... time to order a regulator (rockauto) very good price so we will see... next will be the modification ...did you do this one just the pass. door???
thanks for the help so far
 
I don't know about the older ones, but my 98 has always had speedy windows. Until about a couple weeks ago, my driver's was quick too. It just started getting slow so I figured I'd change the window motor and regulator. Against the brutal 40° cold (anything below 70 is cold to me, and I hate cold) I went and slapped a new one in yesterday. To my dismay, it's still slow. I wonder if the wiring in the door jamb is breaking and I'm about to have a dead window... probably at the most inopportune moment. Especially now that I'm on business for the week, 5 hours from home. And it's down in the 20's here.

Funny enough, I did install relays in the door panel of my 88 Rx7 for the same reason. I did that probably 15 years ago. You can clean the switches, replace the motors, lube the tracks, and clean all the connections along the way. It'll still be slow until you put the relays in. Since then I've had zero issues, and I even upgraded a couple years ago to relays with rubber seals so water won't get in. Now they're permanently fast!
 
I wish I wasn't so dumb with wiring...my 92 needs help on all windows and door locks.

Sent from my SM-N960U1 using Tapatalk
 
Yea ,, lube is a good start but my pass .side motor is now dead. 1st I had no power in the pass door for the window.... The power switch on the driver door will sw. off or on BUT the wire from the switch supply's power to 3 doors which is connected in the wire harness under your driver feet.... Thats ok but when it gets wet over and over it ends up looking like a battery connection green corrosion then ... no power to 2 windows... so that repaired attention to the pass door window and the motor said ,,, Im done pooof... time to order a regulator (rockauto) very good price so we will see... next will be the modification ...did you do this one just the pass. door???
thanks for the help so far


I did both front windows on mine. Now that it is getting cold out the rears have slowed down so I will probably do those as well.


If I had the wiring issue you describe (area gets wet and corrodes the wires), I would probably cut the violet/white wire where it enters the cab and connect all 4 (one from each door) to a 30 Amp fuse with one of these:


https://www.summitracing.com/parts/...1596235377062&utm_content=GSAPI+5ba295df391ba


This would ensure that you have good power going to each door. From there, I would rewire the door exactly as I describe below. This would be much easier than trying to thread a new wire through the loom into the door. Of course you will need to tape off the "live ends" when you cut but this wouldn't be hard.



HTH
Todd
 
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