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Hello from Vermont

Vermont SVT

New Member
Hello, I’m new to the forum I have a mild built 89 5.0 LX convertible. I’m having intermittent issues with my power windows and locks. Intermittently neither will work. When they don’t work it’s always together and I have no power at the fuse box any ideas? Thanks, Jason
 

broncojunkie

Well-Known Member
Well, if no power at the fuse box, then it has to be an issue with the box and/or wiring there... unless I'm missing something. Are you sure you're testing it correctly? Probing the correct socket and all? Reason I ask is because it's much more common for them to stop working from bad switches or harness where it enters the door/door jam area.
 

Vermont SVT

New Member
I used a meter to test for power in the fuse box at the window fuse. I’ve tested at the fuse when it works and get power and when it acts up I get no power. I had to replace the ignition switch because of other problems so I know that’s ok now. I’ve checked the wires going into the door they all look good. I don’t think it’s a switch because when it acts up no switches work. I had a Ford tech try to figure it out and he was stumped. I also replaced the relay up inside the dash by the drivers side speaker. I was hoping a relay was failing but unless I have 2 being a convertible I don’t know the next step.
 

Vermont SVT

New Member
Another thing I forgot to mention is it’s a very random issue. It happens a lot but I can’t pinpoint a cause. It could be parked have the windows not work with the key on of course with the doors closed and without opening a door they’ll start working. Other times it’ll happen driving the window will stop either going up or down then sometimes a minute later they all work again or a hour sometimes a day.
 

broncojunkie

Well-Known Member
My thought is that if you aren't getting power from the fuse box (when this happens), then the issue is going to be from the fuse box and back to the battery.... somewhere in between those two points. Since you're not losing power to other accessories (headlights, wipers, radio, etc), then you can pretty much eliminate the main power source, which is the battery, cables, and power supply to the fuse box.

This is, of course, an overly simple way of looking at it, but I can't think of any exceptions that this theory doesn't apply here. I'm presuming everything you're telling me is true, which is why I mentioned "user error" in regards to where you were probing the fuse box. Hope that make sense!

So basically, I would begin trying to test behind the fuse box. Inspect for loose wiring. You very well may have been on the right path in suspecting the relay. If possible, try checking the feed to and from the relay socket when it happens. Intermittent issues are always a pain to diagnose! You can probably figure out a way to rig up some test probes/wires. I believe they make something for this, but in a pinch, a sewing needle strategically stabbed through a wire can provide a good contact point for testing.

I would start with a careful inspection of this area, though. If you can connect a light tester or bulb of some sort to your window motor, you can watch it while poking around in the wiring behind the fuse box and under the dash. Again, just have to get creative here. You could even have a partner standing by with a meter to tell you when something changes, while you're upside down under the dash.
 
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