I'm having trouble with my factory temp and fuel level gauge. Both have new sending units and are wired correctly and both have power at the gauge. Both gauges go to the left when key is off and go to the right when the key is on. Neither one does anything after that, what is the problem????

 

Are you sure that there are no grounds on the wiring/ Trying performing an resistance check on the wires.

 

Also, go to the fuel sending unit and remove the wire. Check the resistance to ground, it should be 145 ohms or 50 ohms. Ford I think had two deferent types but, it should be one of the two. Using a 145 ohm fuel sending unit, full it would read 145 ohm and empty it would be about 45 ohms.

 

You say you are getting power to the gauges. I believe the gauges should be getting around 5 volts from the voltage limiter (instrument cluster regulator). Check the voltage for the 5 volts. If greater than 5 V than the regulator may be malfunctioning...just guessing. However, here is an article on gauges and fixes....good luck

http://www.mustangandfords.com/techarticles/75259/

 

Thanks for the find Danny. I will be adding that to the FAQ