Hey guys, gals. I need help from your collective experience and expertise. My 2004 FX4 super cab wouldn’t crank the other morning, it appeared to have a dead battery. After sitting on the charger for a while I noticed that the ac/ heat blower was running but my key wasn’t in the ignition. I don’t believe it’s the relay because I’ve tried swapping them around and get the same result. Fan runs continuously until the battery is drained. The fan speed switch does work and adjusts fan speed. I pulled the relay and left the battery on charge all day. Now, with the battery charged and the relay reinstalled, the truck will not turn over. Also, my cluster and odometer do not light up. The radio is getting power but doesn’t seem to be fully working either. I’ve read a little about GEM modules but I haven’t found any in my fuse box which is at the passenger kick panel. I ran a heater on the fuse box for a while in case there was moisture that was causing the issue. I’m leaning toward a bad ignition switch but was wondering what you guys think. Thanks

 

You check the ground lug located near the passenger fuse box in the kick panel? That is a common issue of a corroded ground in these trucks.

 

I did find that ground lug was very corroded. I actually cut the wires and replaced the connector. Attached back to the body with a self tapping screw. Unfortunately this didn’t remedy the issue. Thanks

 

You should also take a look at the grounds (G200 and G303) located behind the driver's side kick panel by the parking brake. G200 ties to HVAC (etc) and G303 ties to Security Module (etc) acording to my 2007 wiring diagrams.

 

did you grind down the spot where you attached the new ground wire/terminal?

havw you had battery load tests ?

 

I have exactly the same issue with my '03 Lariat.

 

FIXED! One of the ground lugs in the driver kick panel was rusted. Took off some of the paint and reattached the ground. Shazam!

 

FIXED! One of the ground lugs in the driver kick panel was rusted. Took off some of the paint and reattached the ground. Shazam! I owe you a 6 pack.

 

thanks for posting solution, makes thread valuable for others searching in future.