1989 240 DL Power window don't work with new relay

johnny volvo · Post by **johnny volvo** » 28 Mar 2014, 15:49

The power window saga continues. I could really use some advice on this.

I experienced a sudden failure of all windows. The fuse has been replaced. I bought a window relay online and located the old one behind the dash and changed it, but the windows still do not operate.

I pulled the relay out about half-way and, using a test light, I found that I had power to the relay at multiple points. I tried jumpering the connections with a piece of wire, but nothing seemed to happen. I did blow the fuse while attempting this and changed it out with a brand new one.

I also checked the ground, which appeared to be fine.

My main thought is that the relay may be defective. Other than that, I can only speculate that it could be the wiring harness. But, would a harness cause complete failure on all four windows. Or is there another component that I'm overlooking?

Is there a way of testing the relay before I buy another?

Post by **mtd240** » 03 Apr 2014, 06:58

Have you looked at the window switches? The "master" switches in the driver side door must have clean contacts, or none of the windows will work.

Picture Walkthrough.

johnny volvo · Post by **johnny volvo** » 05 Apr 2014, 01:56

Thanks so much for your input and the great walkthrough. I'll be working it on the windows this weekend and this will be of great help.

johnny volvo · Post by **johnny volvo** » 05 Apr 2014, 18:19

Well, the good news is that I checked the contacts on the center switch of the master unit in the driver's door and the contacts are clean. I cleaned the other switches as well and reinstalled The bad news is that nothing changed. Still no window operation.

Anything else I should check? I checked the relay again and made sure the ground at that point was good. The test light was on for brown, red, and yellow-blue wires at the relay. That indicates to me that the relay works. Am I correct in that assumption? If so, can anyone think of what else might be keeping the windows from working?

I'd like to stress once again that the failure was sudden. The windows worked fine one day and, two days later, didn't work at all. I checked and replaced fuses, I've got current through to the relay, and it's a new relay. I'm stumped.

Post by **mtd240** » 06 Apr 2014, 17:04

Here is the wiring diagram. Scroll down a few pages.

Another thing to check would be the wiring from the relay to the master switch. The wiring running through the accordion next to the door hinges gets fatigued and eventually breaks.

To test the relay, apply 12V across the terminals for blue/yellow and black (pull the relay out of the car and use the car battery if you don't have a power supply). You should hear a click, and the resistance across the other two terminals (brown and red) should change from infinity to zero.

johnny volvo · Post by **johnny volvo** » 06 Apr 2014, 17:21

Thanks so much for that input, but the mystery is solved.

I remembered seeing a comment from someone on a different thread about the ground at the switches. I jumpered between the ground contact on the switch and metal on the door and, just like magic, the windows worked.

I used a splice connector to run a new wire to the door and it worked. But, by the time I got the door back together, they weren't working again. I suspect it's the splice connector; I had a tough time with it. But, at least I've identified the issue.

Next weekend, I'll run a new ground wire.

Thanks for all your help!