Hi, I have a 2000 F-150 and my lights to my gauges and heater controls quit working. I checked all the fuses inside and under the hood. All good. I swapped a few relays around and no luck. I tried replacing the headlight switch and that did not help. I checked power to the gauges from the headlight switch and there is no power, I then ran a hot wire to the wire that powers the gauge lamps and they do light up, so it is not a bulb issue. I assume I am not getting power, but do not know where else to look? Need help.

 

Has the windshield in your truck ever been replaced? Even if it has not, there is a gem module behind the inside fuse panel (L/S) of the dashboard. Many things are controlled by that module and they are known for getting corroded due to a leaking windshield. Many functions are controlled electronically and a small amount of moisture can produce some mystifying results. Last but not least , there is a reostat that controls the illumination of the dash lights , you might want to confirm it is sending voltage to the dash lights when the lights are turned on.

 

My windshield was replaced in 2008 for being cracked. It has not ever leaked that I know of.
Is the gem module hard to get to? Does the fuse panel need to be removed?
Lastly where is the rheostat located that controls the dash lights?

 

The panel dimmer (rheostat) is in the roll switch next to the headlamp switch. Make sure it wasn't rolled to the off position...

 

The rheostat works fine. I have rechecked my fuses and the #18 fuse has no power to it at all now and the fuse is fine. Do you think I may have a bad GEM module?