What All Does the GEM Control?

[toms89]

Edit: The following applies if you feel moisture in the gem was a possible source for your issues.

I would highly recommend if you replace the gem module you remove and make sure the fuse block in which it piggybacks is completely dry inside.

I say this because when I had issues I really did not notice much if any water in the gem module itself but a fair amount did pour out of the fuse block when removed.

I believe this is due to the design and angle. The gem will tend to drain better. The fuse block is located below and it appears to hold water well. Once you find the assembly you will understand how all the water goes right there. Its because the wiring harness is going down hill right to it. Any water behind the dash follows the wires right to it.

I assume that since the gem controls and monitors various circuits through the fuse block it could have adverse effects on it?!

So again I would recommend pulling the fuse block while your there and drying it out near a source of heat. I set mine near a pellet stove overnight as well as my gem module.

 

[bojaz01]

where on ebay did you find a gem for $90.00? if you dont mind me asking....ive got the same problem on occasion....gauges acting all squirrelly and such....gonna have my windshield checked for leaks before i do anything though......

 

[radar]

How about the cruise control?
Have tried everything else clock-springs, buttons & servo.
Still doesn't work, press on/off & any other switch & the horn blows!

 

[toms89]

How about the cruise control?
Have tried everything else clock-springs, buttons & servo.
Still doesn't work, press on/off & any other switch & the horn blows!

That's too funny !!

Sorry.... I would probably be looking for a short in the steering column but it sounds like you have already been there.

 

[radar]

Yep! Sure have. Looked over wire harness for any damage but haven't any let.
I hope someone can give me a clue.

 

[stamp11127]

I would pull the "speed control switch" assembly in the steering wheel and test the connections.

There are internal resistors for the different settings:
On - 1000 ohms
Resume - 2200 ohms
Set/Resume - 680 ohms
Coast - 120 ohms

Hot wire coming in to the speed control switch is the DB colored wire,

If any of them are at or close to 0, when you press the on and any of the others you have an almost direct path to ground through the speed control servo. You may hear a slight difference in the horn with On & Resume switches.
If the switch passes the test I would test the wires for a short to ground. Disconnect/remove the air bags prior to testing - the dvm will trigger them.

Does your horn work with the horn switches?

 

[stockd15b]

sorry for bumping an old thread. Would it be possible to drill a hole in the GEM, check for moisture and then fill with thermal conductive epoxy, to prevent any from entering?

 

[FordandPolaris]

sorry for bumping an old thread. Would it be possible to drill a hole in the GEM, check for moisture and then fill with thermal conductive epoxy, to prevent any from entering?

Possible sure, but no idea how it would affect it. Worst case, it does not work and you replace the unit anyways (assuming you are seeing problems). Though I would have the new one on hand and ready since no accessories will work in the truck without it.

Replace the windshield seal, or the windshield itself, and depending on how bad your problems are, they will disappear as it dries out on its own. That is how mine ended up.

 

[handyone]

What does "GEM" stand for & where is it located in my '04 EB?

 

[FordandPolaris]

General Electric Module. It piggybacks to the fuse block below the driver's side dash. Are you having electrical issues? Most GEM issues occur in the 1st gen expy's but doesn't mean it couldn't happen to the 2nd gen.

Do you get wet floors on the inside after a heavy rain?