No Start - Wiring problem - MICE!

[Jack McArdle]

In a previous post, I described a problem where we determined the fuel cut-off solenoid was the cause of a no start on my B7800. Everything powers up, the starter cranks, and if I remove the solenoid, the tractor runs.

Well, the plot thickens. The new solenoid did not fix the problem. I started (grrr) trying to trace wiring (ordered a service manual, not here yet), and found a mouse nest in the dasboard! The 4 wires going to the starter relay were chewed bare, and obviously shorted.

So - any wiring experts out there? Everything works except the power to the fuel cut off. All fuses in the fuse block intact. I'm assuming the starter relay is ok cuz the starter motor works fine (although I ordered another one for 8 bucks)

What could be blown that would prevent the cut off solenoid from working? Horse manure is piling up...

Thanks! Gotta love wiring...

 

[Ed Hill]

Well, I don't know the details about the B7800 dash, but I have had experience with mouse nests in central air conditioning units. Look for any circuit boards they may have peed on, because every time they got into the AC, they ruined a board. I had to screen the entire unit and we usually put moth balls inside as well to repel rodents.

 

[palomar]

I am not familiar with you tractor and cannot answer specifcally, but if your components and fuses are ok then the wiring has to be it. Working with wiring is easy you just have to be methodical. The shop manual (when it arrives) should have a wiring diagram and testing procedures for individual components (starters, relays, etc. ) Sometimes damaged wiring, especially in a wiring harness, is impossible to detect visually. You will need a meter with continuity, or resistance testing capability. I would start with the solenoid wiring and test it end to end.

 

[KubotaTech]

There is a customer that we regularly service their tractor, and EVERYTIME I have been there I find a nest. Always one in the air filter, in back of the battery, and last time there was one under the shroud covering the fuel tank. Follow thew wiring from the solenoid and you will prob. find the cause