GC1720 has no electrical power at all

[BusyBacres]

I have recently ran into an issue that has me flummoxed. The tractor has absolutely no power when turning the key(absolutely no lights etc on dash). Parts that have been recently replaced include the starter, neutral safety switch, key switch and the two main fusible links. The battery at the time was good with a full charge.
I was able to jump the starter to start it up so we could move it but I know even doing that the system isnt recharging itself by the alternator. I’ve gotten the repair book for it but for the life of me I’m having a fun time trying to trace the wiring.
I figure it’s one of two things a bad ground(I’ve checked them and they seem good but might have missed something) or the wire going to the key switch that is ultimately the power source for everything.
Has anyone ever encountered this or have any suggestions????

 

[LittleBill21]

so out of the 15 parts you bought, did you happen to buy a volt meter?

safety switches don't stop dash's lighting up, it appears since you replaced mostly everything minus the harness, that its prolly a wire issue.

post the wiring diagram for the machine, and we may be able to help you find the issue

 

[LarryS]

I once had a car that had a broken battery post. It was broken just inside the case. It'd die at a traffic light but wracking it on the post made enough connection to get going again.

I had another vehicle with a mysterious die-while-driving malady. To troubleshoot that I made a test light with small alligator clips so I could monitor different points in circuits while driving. Traced it to a flaky fuel pump relay.

On a MF tractor, check and monitor all the switches that kill it as a safety feature: seat switch, neutral switch, PTO lever, and possibly more.

 

[LittleBill21]

On a MF tractor, check and monitor all the switches that kill it as a safety feature: seat switch, neutral switch, PTO lever, and possibly more.

Safety switches do not disable dash lights. they kill starters or kill fuel pumps, that's it.

 

[BusyBacres]

Here are the wiring diagrams

 

[LittleBill21]

your going to need to link the manual. I can't read that well enough

 

[kenmbz]

Without a volt meter to see where voltage goes away, hard to tell.

 

[WranglerX]

Positive (+) side of battery goes directly to large terminal on starter, from there power (voltage) goes to fuses #11 and #12.... Check for power (voltage) at fuses #11 and #12 first.... Negative (-) side of battery should go directly to chassis as "ground"...

Be sure you have voltage on both sides of fuse #12.... From fuse #12 voltage (power) goes to main switch terminal "B" (#25 on diagram) and to fuse #3 for engine stop solenoid. ....

Blurry lettering for #12 fuse reads "A slow blow fuse that is green and protects the main circuit"...


Also this could become your new best friend...

Quite easy to use.... Put alligator clip on good clean ground (negative battery post), use probe to find "power" (12 Volts) lamp light where you have power...

If you have doubts probe is functioning, put alligator clip on ground terminal (-) of battery and touch probe end to positive post (+) of battery if probe is good lamp inside will light...

 

[Dmacleo]

iirc (don't have the service manual in front of me) a blown diode can cause the charge issue as well as prevent power from flowing thru switch.
don't quote me though. use a voltmeter/test light before buying more stuff.

 

[Joel/ak]

I once had a car that had a broken battery post. It was broken just inside the case. It'd die at a traffic light but wracking it on the post made enough connection to get going again.

I had another vehicle with a mysterious die-while-driving malady. To troubleshoot that I made a test light with small alligator clips so I could monitor different points in circuits while driving. Traced it to a flaky fuel pump relay.

On a MF tractor, check and monitor all the switches that kill it as a safety feature: seat switch, neutral switch, PTO lever, and possibly more.

On our 1705 we had that problem. It was a positive cable at the starter. Totally dead, wiggle the wire and it came to life. Fixed it and no problems for over a year.