Combines a couple of questions about a 1989 R50 Gleaner

[tbran]

Many older combines_ tractors have a problem running a bunch of lights as the switches and connections get corroded and curcuits in general increase resistance. Your situation is a little unique but is probably due to incresed amp requirements due to voltage drop as alt output does down. A simple cure is to install a solinoid or repay for the lights using the light switch only as a trigger for the relay. Wire the relay power source to the door solinoid power stud either battery side if you want to use the lights w_o switch on or the other post for keyed only operation. As to the fuel, open access plate and remove the fuel sending unit and operate it by hand watching the readout . It works like any fuel gauge - the more resistance in the winding as fuel lowers and float lowers, the lower the readout either in digits or gauge hand.

 

[Ed_Boysun]

I'd bet that you have a wire rubbed through and shorting somewhere that is causing the fuel to read above full all the time. My R50 quit doing that after we taped a new wire to the old one and pulled it through to where it connected to the guage.