This 1997 Ford F150 needs the GEM module changed due to multiple conditions. To see testing that lead to this repair please click here. The GEM module is located at the rear of the interior fuse box.
The first step is to remove the trim panel that covers the gap between the upper side of the steering column and the dash. It just unsnaps from the dash. It makes it a little easier to remove if you move the shifter all the way down to drive 1.
With that out of the way the lower dash cover can now be removed. Most of the screws have 7 mm heads but there are two that have 8 mm heads.
Those two are at the lower edge of the fuse box.
One wiring harness needs to be disconnected from the panel.
Now the screws for the fuse box can be removed.
The wiring harnesses can be removed from the back of the fuse box. Two 10 mm headed bolts at the center of each connector.
Next remove the tube brace from around the bottom of the steering column. Four fasteners with 13 mm heads.
Now wiggle, pry and twist the fuse box and GEM module assembly down.
After the assembly is down far enough unplug the remaining harness connectors from the GEM module.
Almost there.
The assembly is now free of the vehicle.
The GEM module is held to the back of the fuse box by three phillips headed screws.
Easy to remove Now.
With the three screws removed the GEM unplugs from the back of the fuse box.
I put it all back together and checked my repair for power to the driver’s power window switch.
Hi Ron L.,
I like to keep things as simple as possible, so I would recommend tackling either the battery drain condition or horn inop problem first. Fix one at a time, starting with the easiest to diagnose. Hopefully finding and repairing one problem may help with the others. Do you have a multimeter and/or a test light? Wiring diagrams?
I have a 1998 2wd f150 no pwer windows, ac, 6 cyl, horn quit, heater fan stayed on sometimes after ignition was turned off, sporadic wipers than finally quit all the way, constant drain on battery. Replaced the GEM with the proper one from Autopartscheaper.com using the correct part numbers ……..still have all the same problems. There was no water getting to the old Gem or fuse box. Thoughts? Ron L.
Hi Brandon,
Check fuse #12 in the under dash fuse box. I would suspect that the fuse and/or the horns are blown. More than likely the door lock actuators are faulty for the power door locks since you stated that they wiggle a little when activated.
Hi Randy,
Yes, it is likely that you have a faulty GEM. Although water intrusion and corrosion can be a factor many GEM’s fail on their own. You could wire around the GEM for the more basic systems but it would be time consuming and somewhere down the road other problems such as a battery drain will develop.
Sorry if this is the wrong place to do this but could not find link to ask a question I have a 1999 f350 four door my horn just stopped working and when i press the alarm button on the for the relay in the dash fuse box clicks, when the relay is removed the clicking moves to a black box mounted above the transmission tunnel on the firewall. None of the doors will lock or unlock the black box just clicks and the locks just sort of wiggle. Everything else works windows, dash lights, interior lights, seats, Any idea what this box is? And what the issue could be? Thanks, Brandon.