Headlights inop

[Shortbed70]

Ok so I have been having issues with the fuel gauge (gauge inop) and the headlights also seem to be having the same issue. I am wanting to get this fixed but can't find any broken wires? The fuel gauge I have already jumped the sending unit and still no gauge movement and the lights don't work at all. I'm going to buy a fuel gauge tomarrow after work so I will see if that works. 1985 643

 

[gengine]

The first thing to check is your fuses if you haven't already. I've never worked on a tractor like yours, but generally those two things are unrelated in the circuitry. In one scenario, is it possibly your key switch? Here's where I'm going with this. Your key switch cuts off the power to the gauges so they don't drain your battery. If your headlights normally turn off with the key switch as well, then the relay(s) controlling each of those is no longer getting power from the key switch, wether it's switched on or off.

 

[gengine]

Wow, I must be still tired this morning. I just realized your talking about a bobcat skid steer. I've never worked on a 643, but have on others, newer and older. The key switch still makes some sense. The switch sends voltage to relays that let your gauges and lights turn on. Here's what I can gather.
1. The switch isn't sending the power to the relays
2. The wiring isn't getting all the way to the relays
3. The relays are needing replaced
After that, I think the two will be separate circuits unless they share a common ground. That is unlikely since they are so far apart.
Good luck, and keep us posted.

 

[Shortbed70]

Well the book is pretty gray as far as what wire going to the gauges actually hold 12 volts but I did find one wire at the light switch that has 12 volts but it doesn't send power through so guess I'll buy a switch and see

 

[wild hungarian]

have you checked all the grounds? happened to me once

 

[Shortbed70]

Well all the other guages are working and I thought they were all on the same ground at the back of cab by sending unit.

 

[Shortbed70]

Well the ground shows continuity and still no fuel level. I've crossed the sendin unit wires, and just put a new gauge in and still nothing! I'm am at my wits end... I still need to replace the light switch because the connection are all corroded. Grounds seem fine though... Any clues