Rat Disaster. Need Electrical Help.

[N80]

Update: Got it all wired up. Used butt splices. I got the kind with heat shrink. I found that if the crimp was not made all the way out to the edge of the butt splice they tended to be weak. However, when done properly they hold just fine. I did find that the crimp tool sometimes scored the heat shrink and when heat was applied it would pull away from the connector and expose a little of the metal connector. I wrapped any of these with additional electricians tape. It turns out that the glow plug wire was fine. The wire that was missing was the temp sensor so I wired that back too.

Once it was all wired up I cranked her up and nothing. No dash board lights. No gauges. I started to panic and remembered the fuse. It was blown. Replace it and everything worked fine except the fuel gauge. I followed the wiring from the float unit in the tank all the way to the dash. Checked all my connections. Everything was fine. The fuel gauge has been working on and off for a few years but the needle would still move some. Now, nothing.

I could not figure it out. As mentioned before there are two black wires. Both grounds and both go to the same lead in the wiring diagram so I don't think that is it. I cleaned the connections at the float/sender. Tried to remove the float but one of the hood hinge pins makes it so you can't get it out without removing, or at least loosening the whole fuel tank.

The shop manual says to test voltage at the float/sender. What do I test this with? I've got a voltage tester but it is for home electrical. Will it work on a 12 volt tractor system?

I'll probably just give up on the fuel gauge.

Anyway, did an oil and filter change, fuel filter change, air filters changed and everything lubed while I had everything apart.

 

[N80]

Update: Got it all wired up. Used butt splices. I got the kind with heat shrink. I found that if the crimp was not made all the way out to the edge of the butt splice they tended to be weak. However, when done properly they hold just fine. I did find that the crimp tool sometimes scored the heat shrink and when heat was applied it would pull away from the connector and expose a little of the metal connector. I wrapped any of these with additional electricians tape. It turns out that the glow plug wire was fine. The wire that was missing was the temp sensor so I wired that back too.

Once it was all wired up I cranked her up and nothing. No dash board lights. No gauges. I started to panic and remembered the fuse. It was blown. Replace it and everything worked fine except the fuel gauge. I followed the wiring from the float unit in the tank all the way to the dash. Checked all my connections. Everything was fine. The fuel gauge has been working on and off for a few years but the needle would still move some. Now, nothing.

I could not figure it out. As mentioned before there are two black wires. Both grounds and both go to the same lead in the wiring diagram so I don't think that is it. I cleaned the connections at the float/sender. Tried to remove the float but one of the hood hinge pins makes it so you can't get it out without removing, or at least loosening the whole fuel tank.

The shop manual says to test voltage at the float/sender. What do I test this with? I've got a voltage tester but it is for home electrical. Will it work on a 12 volt tractor system?

I'll probably just give up on the fuel gauge.

Anyway, did an oil and filter change, fuel filter change, air filters changed and everything lubed while I had everything apart.

 

[Scott65]

Usually a meter that will test home circuits will do automotive as well, but not always. It needs to be a multimeter with AC and DC. AC will have a symbol that looks like a single squiggly line. The one you need, DC, will be 2 lines. The top solid, the bottom dashed. Or may appear as dots. If it has auto range, select that. If not, select 10. That will put the decimal in the right spot for your 12.?? volt system.

It's pretty common for a fuel float to be a simple variable resisted ground circuit through the float. If this is the case, an easier way to check is to find the wire behind the dash where you know is coming from the gauge and ground it. See if the gauge pegs one way or another. Then go to the tank end and ground it. If you don't get the same result, there's a break in the wire. If you do get the same result, the problem is in the tank. Typically a corroded wire in the winding or a sunk float. But it would seem like something external since it changed with the rodent damage

Glad to hear you got the rest ironed out! Thanks for keeping us updated!

 

[MinnesotaEric]

Update: Got it all wired up. Used butt splices. I got the kind with heat shrink. I found that if the crimp was not made all the way out to the edge of the butt splice they tended to be weak. However, when done properly they hold just fine. I did find that the crimp tool sometimes scored the heat shrink and when heat was applied it would pull away from the connector and expose a little of the metal connector. I wrapped any of these with additional electricians tape. It turns out that the glow plug wire was fine. The wire that was missing was the temp sensor so I wired that back too.

Once it was all wired up I cranked her up and nothing. No dash board lights. No gauges. I started to panic and remembered the fuse. It was blown. Replace it and everything worked fine except the fuel gauge. I followed the wiring from the float unit in the tank all the way to the dash. Checked all my connections. Everything was fine. The fuel gauge has been working on and off for a few years but the needle would still move some. Now, nothing.

I could not figure it out. As mentioned before there are two black wires. Both grounds and both go to the same lead in the wiring diagram so I don't think that is it. I cleaned the connections at the float/sender. Tried to remove the float but one of the hood hinge pins makes it so you can't get it out without removing, or at least loosening the whole fuel tank.

The shop manual says to test voltage at the float/sender. What do I test this with? I've got a voltage tester but it is for home electrical. Will it work on a 12 volt tractor system?

I'll probably just give up on the fuel gauge.

Anyway, did an oil and filter change, fuel filter change, air filters changed and everything lubed while I had everything apart.

Allow me to introduce you to the best cheap multi-meter that I know of. Only real drawback is that it doesn't beep on continuity. Amazon.com: Mastech MS8268 Digital AC/DC Auto/Manual Range Digital Multimeter Meter: Industrial & Scientific

 

[Coyote machine]

Any quality multimeter will do what you need to test your fuel sender/gauge.
Liquid electrical tape will seal the holes in shrink wrap, butt splices, etc. Marine suppliers sell kits of connectors, shrink wrap, and small palm sized Butane torches that allow waving the flame under shrinkwrap to make it shrink.

Ancor brand is one quality manufacturer. I use them all the time on my boat and tractor. Products | Ancor

 

[timster2]

Next trip near a Harbor Freight pick up one of these free meters, no purchase required and good till Jan 15, it can do the job. Just print this coupon out or load it on a smart phone. I have several and they work just fine for simple tasks.

 

[N80]

Scott, thanks for the advice. Will test things next time I get down to my cabin. And thanks for the tips on the meters and such guys.

 

[k0ua]

If you asked me (and no one did) In 8th grade science class, there should be a day devoted to the use of a multi-meter. With actual lab time, measuring batteries, wires, resistors, variable resistors etc. Then some class time with a brief overview of ohms law. Yes this might take a week of 1 hour classes, but I guarantee, teaching something practical to children that they can actually use for the rest of their life would be worth a whole lot more than some of the current parts of the curriculum. I realize my ideas are not mainstream, and it will never happen, but I still think it is a good idea.

 

[N80]

I agree completely. I had three years of shop class from 6th through 9th grade and the skills I learned there, mostly carpentry and wood working, I still have. However, the part of the brain that understands electricity is missing in my brain. I took physics in college and I passed it, but electricity, like my two years of Spanish, did not stick. No habla electricity.

 

[k0ua]

I agree completely. I had three years of shop class from 6th through 9th grade and the skills I learned there, mostly carpentry and wood working, I still have. However, the part of the brain that understands electricity is missing in my brain. I took physics in college and I passed it, but electricity, like my two years of Spanish, did not stick. No habla electricity.

Give me two hours with you, and a multimeter, and a few props, and I could get you to the point where you could do and understand all that you need to know to fix anything electrical on a tractor. And I would be happy to do it.