This 1997 Ford F150 came in with three complaints. The power windows do not work. The wipers do not work and the interior lights do not work. Figuring that they were all related I decided to test the easiest system to access, the power windows. I pulled the driver’s side power window switch assembly up and checked for power at the light blue/black wire with the key on. No power.
I then went to the interior fuse box and removed the battery saver relay. It is the small relay second from the top left corner.
I checked for ignition power on the lower right terminal, 12 volts, good.
I checked for ground at the upper right hand terminal by first placing one lead of my voltmeter to a positive battery source, 0 volts, bad. That in itself is enough to show that the GEM module is faulty but I also looked at GEM data with a scan tool and saw that internal system voltage was 22 volts. Hard to do with a 12 volt battery. Diagnosis of a faulty GEM module. To see how to replace the module please click here.
This is the reading with a new GEM module across terminals 85 and 86. Just like it should be 12 volts. Another important note is that I asked the customer about water leaks on this side of the truck and also closely inspected everything as I disassembled looking for signs of water intrusion. Water leaks are a big problem with these modules.
Again with the new GEM installed there is now power on the light blue/black wire.
In case you have not already figured it out if the windows had to be operated to raise a downed window you could do one of two things if there is no power at the light blue/black wire. One, you could apply 12 volts to this wire with a jumper wire. Two, you could jumper terminals 87 and 30 together at the battery saver relay. The second will also test the wiring in the door jamb as well.
Thank you for the info. I wanted to try using the jumper method on pin 87 and 30. But on my power saving relay that I have its numbered 1 through 5. How do those numbers relate to the stock power saving relay that is numbered 1 through 5?
Thanks
I have never heard of this exact complaint on this type of vehicle. My best guess would be an internal short in the master power window switch, crossed/shorted wires in the driver’s door jamb wiring harness or added wiring by someone trying to make something work. Such as a previous owner.
I have a serious issue with my 1997 f150, my
Driver power window will only go up, when I press down the auto relay starts clicking and the interior lights flash, I replace the relay and I replaced the motor and no difference, when I had the motor off I noticed that when I press the button for the passenger window it cycles the driver window up, that made me think it was that master switch so to make sure, I went around to the passenger door and when pressing either up or down on the passenger switch it still cycles the driver window motor up, I have a hard time believing a short is causing all of this and I am absolutely stumped and already put a lot of money into a problem that seems never ending… Please help
There are several aftermarket companies that rebuild these units and have them available. Standard Motor Products and A-1 Cardone are just a couple. Check with your preferred parts supplier.
Is a factory ford repair shop the only place to buy the GEM ? Do you know of any other places to buy a GEM? I have a 1997 F150 that needs a GEM according to this column. NO windows, wipers, 4×4 doesn’t come on, no interior lights. I’ve taken GEM out for the particular part number. I can also if needed get the VIN.
slo383@yahoo.com
thanks