RV Repair: 95 RV w/Ford 460 idle issues, gas gauge, ford 460

Question
Hi - I have a '95 Rexair with a Ford 460 (54K miles). Recently had overheating issues with tranny so installed a new deeper cooling pan, larger cooler w/fan, and a temp gauge. After install, had an engine issue (not sure is assocaited). It starts fine, revs great, oil pressure and charging is good. But the thing will not idle. When I let up on the throttle, it dies. I also noticed that the tach does not work any longer, and also noticed that for some reason the gas gauge goes to empty once the ignition is turned on. With key off, the gauge registers the 1/4 tank that there is. Any ideas?

Answer
Rexair is notorious for electical issues.  We used to carry them here at our dealership, but with the numerous electrical problems they had, and their unwillingness to help with the problems, we stopped carrying them and sent what little inventory we had back to the factory.  

I don't know where to tell you to start, but it does sound like you have an electrical problem

Garry