on my dads 1985 ford diesel pickup both tanks quit registering on the gauge (yes it has fuel in it). we checked all the conections and they seem to be good, anybody have any ideas as to what happened? the floats couldn't have both died at exactly the same time could they? do the gauges ever go bad? any ideas? am I missing anything? checked the fuses also in case anyone wanted to know. I am stumped. please help!

 

I had this same problem on an 84 F-150. In my case, the printed circuit on the back of the instrument cluster was bad. This was a few years ago & the part was on backorder from Ford for several months(I doubt if it's still available from Ford). I finally gave up on a new printed circuit & got an entire cluster from a junkyard. However, the gauges themselves are also known to go bad. I would check the gauge first. If it checks out OK, look at the printed circuit for any loose connections, burned places, etc. There are a few very thin, round, brass looking connectors on the circuit. One of these had come loose on mine & caused my problem. It looked as if it could be reattached, but I was told it couldn't. If you have to replace the entire cluster & want your odometer reading accurate, you can install your speedometer/odometer in the new cluster.