4020 lights

The lights operate but not properly. Here is what happens:

1. Key switch on, engine not running. The gen light is on but not the oil light. The fuel gage doesn't work.

2. Key switch on, engine not running, light switch on "work". All fender lights on, rear on, gen light on, oil light on, fuel gage works, dash light is bright.

3. Key switch on, engine not running, light switch on "High". All forward fender lights on, rear off. gen light on, oil light on but is dimmed, fuel gage works but reads lower level, dash light works but is dimmed.

4. Key switch on, engine not running, light switch on "Low". No fender lights, no rear light. Gen light is on but not the oil light. No dash light.

No. 2 above is the only setting where everything works the way I think it should.
No. 3 above has to be an important clue with the dash, and oil lights dimmed, and the fuel gage reads lower. With the engine running the only difference is that the gen and oil light are off as they should be.

I looked behind the switch panel. It looked like a factory stock setup. I found that moving the wires around made the fuel gage function intermittent with the light switch in "work" position, but I couldn't tease the gage into moving with the light switch in the "off" position. I took the larger modular plug apart and it was quite dirty, and there was a little corrosion. I cleaned it up, shined up the contacts and put it back together, but no change in anything.

So to me it seems like bad switch or incorrectly wired. My son who has been the only one to use this tractor says that the fuel gage used to work without the lights having to be on.

So I would appreciate any others thoughts on this.

And I too think the ground wire between the batteries is damaged. Some vintages had a fuse there, some used a battery cable, some just a small wire, but when that wire is open the lights operate wierdly because without the headlights, there is little to balance the voltage to ground and those small lights as well as the fuel gauge work of a 12 volt circuit connected to ground.

Gerald J.