YM 2000 electrical problem

[Maxthompsonm-HT]

Mt Yanmar had a loose ground cable on the battery. I tightened and cleaned that up and still no crank. When I put a voltmeter across the battery when I turn the key on I have 3-4 volts. The same if I go to the engine block. OK bad cell in the battery, replace the battery, same results. I tried jumping the starter without the ignition switch in the circuit, jumper cables to the block and starter terminal. short jumper from post on starter to solenoid. Nothing. I pulled the voltage regulator. every wire going in save the white with red is common to the case/ground. Any suggestions?


I hate to just swap parts until I have some more input.

 

[Norm-HT]

<QUOTE author="Maxthompsonm"><s>

</s>Mt Yanmar had a loose ground cable on the battery. I tightened and cleaned that up and still no crank. When I put a voltmeter across the battery when I turn the key on I have 3-4 volts. The same if I go to the engine block. OK bad cell in the battery, replace the battery, same results. I tried jumping the starter without the ignition switch in the circuit, jumper cables to the block and starter terminal. short jumper from post on starter to solenoid. Nothing. I pulled the voltage regulator. every wire going in save the white with red is common to the case/ground. Any suggestions?


I hate to just swap parts until I have some more input.<e>

/e></QUOTE>

You troubleshooting procedure is very confusing. Why do you turn the key on to test the battery? How do you know the old battery was bad? Check battery voltage. If below 12.6 charge it. If not, troubleshoot starting problem. put everything back together.

 

[winston-HT]

Clean the negative cable where it attaches to the frame.

 

[Norm-HT]

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[alan-HT]

Low voltage from a new battery (installed) suggests a short in the system, so I wouldn't leave the battery connected until fixed. Not sure why you'd connect anything to the block.

To bypass the key, jump from the battery positive to the starter terminal (which is neither of the two large identical terminals). I think connecting otherwise can wreck the reg, at least the old (factory) style.

 

[PatrickHanna-HT]

The block is grounded. You can jump a vehicle with the negative cable clamped to the block. I wouldn't, but you can.

 

[norfolktoad-HT]

This is probably the most common fault with these 30 - 49 yr. old Yanmar Tractors. This has been documented many times in this forum. I am fairly certain your problem is bad connections. Firstly check the battery voltage with the battery disconnected from the tractor, if 12.5 or above the battery is OK, if less charge it up. Reconnect the battery and retest at the starter if much lower than the original test it points to dirty connections. Clean the battery terminals, the ground on the chassis and its connection to the block. Also clean the terminals on the starter. All terminals should be shinny especially the one on the chassis, once this is done the tractor should fire up.

Best of luck

Mike