Smoking wires

[Hotroddoc]

I have a John Deere 750 compact tractor. I installed a battery quick disconnect about a year ago. After sitting for a week, I connected the battery. Immediately wires started smoking, specifically the red wire from the voltage regulator which burned through the insulation while I frantically disconnected the battery.

I looked for something that was causing the short but could not find anything obvious. Does anything think that it is a bad voltage regulator?

Thanks,
Gary

 

[kebo]

Is it possible mice chewed through some wires maybe? Or possibly one of the wires on the VR had been rubbing on something and worn through and was touching metal? If everything was working just fine when you last used it, I seriously doubt that the VR went bad just from sitting up for a week.

 

[Don87]

I'm not familiar with a 'battery quick disconnect', but everything tells me to look there first.

If the key was off, there should be no current moving..........so that eliminates a lot of things.

But melting the wire to the voltage regulator is usually only caused by a reverse hook-up.......with the key off.

Or a major dead short otherwise.

 

[allis180]

You indicated that you reconnected the battery. I connected one backwards once and smoked some wires. I hope that isn't the case with yours, but something to check.

 

[Hotroddoc]

The battery disconnect just disconnects the Positive terminal. It has a knob screw to re-connect it. The battery is wired correctly. The key was off when I re-connected it. There was a mouse nest in the key area but no frayed wires.

If this is a clue, I installed the quick disconnect because the battery would die if I left it connected. Does this point towards a bad VF?

 

[Don87]

The battery disconnect just disconnects the Positive terminal. It has a knob screw to re-connect it. The battery is wired correctly. The key was off when I re-connected it. There was a mouse nest in the key area but no frayed wires.

If this is a clue, I installed the quick disconnect because the battery would die if I left it connected. Does this point towards a bad VF?

This definitely points to a dead short somewhere. some vehicles have constant power to the starter like a Chevy, but is activated by the key, others, as in Ford design, had power to the solenoid, but then was activated by the key.

Sounds like you need to trace some wiring, unless you happen to have a schematic(which makes things a little easier, but not much).

I should note that they were basically the same design, just that the solenoid was in a different location. Ford on the fender, Chevy on the starter.

EDIT: The 'key' to your situation is actually the 'key'............no pun intended.

If key was off.........check towards starter and alternator...........if key was on............could be most anywhere( but most likely near the starter or alternator)

What I'm mainly saying is..............you have 1 problem that got worse(thus the need for the quick disconnect), or you also have a second probllem, that melted the wire.

I would go with number 1.

 

[Snaker]

If you found a mouse nest, odds are that some of the materials included wire insulation and came from somewhere fairly close to the nest.

 

[Hotroddoc]

Thanks guys. I will start to trace the wiring tomorrow. Upon first inspection, I did not see anything.

 

[Skyco]

Keep in mind too that mouse urine is extremely corrosive, if it gets into components or connectors it can cause problems...
The mice aren't smart enough to not urinate in their living area.
At my camp I had a portable gas water heater that was electronically ignited on demand, dang mice built a nest in it and ruined it.

 

[Hotroddoc]

The burnt red wire is the only damaged wire it branches off of the main
12 volt primary white wire that comes off the starter and connects to the ignition switch. I put one end of my continuity tester on the red wire and the other on a ground- No short. I reconnected the battery with the VR disconnected - no short. The problem seems to be the VR. When I put one probe where the 12v red wire should go on the VR and the other on a ground, I get a continuous circuit. Conclusion - bad VR. Now I have to find a new one somewhere.

Thanks for everyone's comments