Months ago I saw a thread about direct wiring the rear windows on an XJC so the window switches fed power to a relay instead of the window motor. I’ve searched the forum with every term I can imagine, but haven’t been able to find it again. I’m going to strip my interior and retrofit Dynamat, so it would be a great time for it. If anyone has any idea about that post, experience, and/or better a copy of the wiring diagram, it would be greatly appreciated.

 

Check the wire diagram for your car. does the switch for the window control the hot leg or the ground leg for the motor.

My GUESS sss would be the hot leg.

THEN IF YOU ARE NOT UP ON HOW A RELAY FUNCTIONS, Study it. Apologies for the caps, only partly intentional!!

The relay has two circuits. The load circuit and the control circuit.

Load. Hot wire to one pin. Another to the window motor

Control. Switch to one pin other pin to power

The top of many bosch typerelay has a schematic as to the functions of the usually four pins.

Relays have fascinated me for decades..

Carl.

 

Someone had previously posted how to run the window motors straight off battery power, using the window switches to control relays that feed power directly to the motors. I’ve seen video elsewhere; it’s a dramatic increase in power. I understand enough about relays to know I need a wiring diagram to work from.

 

Here's one example. You run a heavy but fused +12 to the windows area and light guage wires to the switches.
https://www.rx7club.com/1st-generati...indows-961088/

I like to use a DEI 535T window module one in the front, and one in the rear. This way you get 1 touch function too. I put 2 modules center console and run new wires to motors.
You can learn about it here. Does lots of things. On my personal Coupe when I lock the doors all the windows go up automatically... staggered too, rear windows first, then fronts. It make it easy, I get out lock and walk away.
https://pdf.ampire.de/directed/535T_englisch.pdf

If your windows motors are old and have worn brushs nothing will help but new motors. I used Series 3 Windows motors and regulators front and rear on my coupe. The modern Brose motors are stronger, lighter and use less current. I swaped out the heavy lift spring from the coupe windows regulator... little cutting here, some welding there... all done. But that's just how I roll. I made a post with all the details a few years ago but cant find it.

 

Hello there New to the forum. Had my 89 xjs conv for about 4 years now, and when getting back on the road this spring, my top doesn't work at all. no clicks or hums from the control box at all. I spent my career fixing medical electronics, so I know my way around a circuit. i can raise and lower the rear windows and top by jumpering out the relays, and all the gnd inputs from the park brake, neutral switch, and top control switch are there. seems like the ECU itself is bad. anyone else had this problem, and if so , is there a fix besides replacing the ECU, if I can find a functioning one at a reasonable price. Thanks Rodger

 

You are in the wrong forum. This is for the XJ sedans and coupes, not the XJS. Ask this over in the XJS forum, and many people there can help you.

Jon