My 1984 Datsun/Nissan 720 lost the connection with the fuel & temperature gauges at the same time. I was told the fuel gauge has a common problem in the tank but that wouldn't be my case cause that wouldn't cause the temp gauge to quit at the same time. For years it has stayed off and now & then would start working for awhile when I hit a bump. I got a universal temp gauge and keep a can of gas in it in case I run out. I know there must be a short somewhere but does anyone have any idea of the most likely locations where I should look??? Thanks

The instrument cluster has a voltage regulator for the fuel and temp gauges in the instrument cluster, it is in the wiring diagrams, either it has given up, or there is a bad connection somewhere between the power source and the VR.
Another thing you need to check is the fuses, just because it looks good doesn't mean it is, when I start having electrical issues that have to do with power, they are the first thing I change out, they are cheap, I had one fuse that had to be wiggled all the time to get the radio to work, screwed up fuse block.

Thanks. I'll recheck the fuses for tightness, tho I'm pretty sure they're good. This has gone on for years. I'll see if I can figure out about the instrument cluster & wiring diagram - will probly have to pull out the book for that one