YM 2000 Electrical Problems
- Thread starter Gary2
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normde2001
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"I will return the alternator to the shop and ask them if they will disassemble and check the individual diodes. Thanks for all the responses; this is truly a great forum because of you. Will keep you posted, Gary'
I don't know how you are measuring that voltage, but I can't imagine that alternator testing good putting out that kind of AC voltage. The regulator could be shot now. With the reg disconnected you should see 22-30 vdc out of the alternator. Unless your BIL works in the alternator shop, I'm sure you can replace the alt/reg cheaper than they can disassemble, test and replace diodes/rectifier in the alternator.
I don't know how you are measuring that voltage, but I can't imagine that alternator testing good putting out that kind of AC voltage. The regulator could be shot now. With the reg disconnected you should see 22-30 vdc out of the alternator. Unless your BIL works in the alternator shop, I'm sure you can replace the alt/reg cheaper than they can disassemble, test and replace diodes/rectifier in the alternator.
California
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- Jan 22, 2004
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- 14,680
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- An hour north of San Francisco
- Tractor
- Yanmar YM240 Yanmar YM186D
As Norm noted, getting what you already have to work properly is the least expensive solution.Gary2 said:
Also I am a strong believer in staying as close to stock configuration as possible, especially as these tractors approach 30 years age. In the future, diagnosing an undocumented mish-mash of cobbled-together parts would be a nightmare. The present configuration using '72 Datsun (Nissan) alt/reg is identical to what Yanmar used originally (except it produces greater output) so anyone properly trained in Yanmar, Datsun, or Hitachi charging systems can diagnose it.
You might take the regulator along with the alternator if you go back to that alternator shop for further diagnosis. And be sure his test setup has a shutoff like the ignition key on the tractor, so he can get a shock too. I would print out and take along the wiring diagram, too.
You mentioned the lights burn out when the key is switched off. Is this with the engine running, or stopped? The oil bulb should not have a path to ground (through its sensor) if you turn off the key with the engine running.
Does the voltage surge occur if the ignition is switched on, then off, without starting the engine?
This is a strange one. Keep us informed as you discover new info!
Norm and California:
When I took the regulator to the alternator shop the first time they said they were unable to check it.
The idiot lights blow with the engine not running when turning off the ignition. I believe you are correct in that the oil light does not blow when turning off the ignition with engine running (too many bulbs ago).
The voltage does surge without the engine running while turning off the ignition switch.
I would have already replaced both units if I was confident this would solve the problem. I don’t remember the exact sequence of events but about a year ago when I replaced both the alternator and regulator and I experienced the high voltage. I reinstalled the original Hitachi regulator and the problem went away except for an occasional period when the idiot lights would not work. Then, months later I found that there was short in the original fuse block and wiggling it would restore the lights. I replaced the fuse block and reinstalled the new regulator and everything worked ok for the last 6 months. Then a few weeks ago the high voltage returned.
I would like to ask one more regulator question before purchasing a new regulator and alternator. I have included a picture of my regulator (the NAPA VR521) and labeled where each terminal from the tractor goes. Can anyone tell me if these terminations are correct? Also, on the new unit I am thinking of buying the transistorized model, would this be recommended? Thanks Gary
When I took the regulator to the alternator shop the first time they said they were unable to check it.
The idiot lights blow with the engine not running when turning off the ignition. I believe you are correct in that the oil light does not blow when turning off the ignition with engine running (too many bulbs ago).
The voltage does surge without the engine running while turning off the ignition switch.
I would have already replaced both units if I was confident this would solve the problem. I don’t remember the exact sequence of events but about a year ago when I replaced both the alternator and regulator and I experienced the high voltage. I reinstalled the original Hitachi regulator and the problem went away except for an occasional period when the idiot lights would not work. Then, months later I found that there was short in the original fuse block and wiggling it would restore the lights. I replaced the fuse block and reinstalled the new regulator and everything worked ok for the last 6 months. Then a few weeks ago the high voltage returned.
I would like to ask one more regulator question before purchasing a new regulator and alternator. I have included a picture of my regulator (the NAPA VR521) and labeled where each terminal from the tractor goes. Can anyone tell me if these terminations are correct? Also, on the new unit I am thinking of buying the transistorized model, would this be recommended? Thanks Gary
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California
Super Star Member
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- Jan 22, 2004
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- An hour north of San Francisco
- Tractor
- Yanmar YM240 Yanmar YM186D
75 to 90 volts with the engine stopped? This one's way over my head. I can't imagine anything to cause that.Gary2 said:
My Datsun regulator is apparently solid state. The wires come right out of the poured-in plastic.
The wires terminate in the correct connector (6 blade?) to mate with the tractor's plug.
I labeled the regulator's wires by tracing where the chassis wires went after they left the connector, and also by looking at the wiring diagram.
Then I took the regulator back to Autozone and tested it using the wiring hookup for a 72 Datsun to verify I had identified the wires correctly. Eveything worked. The connector on the Yanmar had the same terminal positions as a 72 Datsun.
I'm baffled. I don't know what to suggest.
California
Super Star Member
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- Jan 22, 2004
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- 14,680
- Location
- An hour north of San Francisco
- Tractor
- Yanmar YM240 Yanmar YM186D
My tractor's wires matched the wiring diagram but the 'Datsun' replacement regulator had all different colors. That was why I did the detailed tracing and verifying I described above.
FL_Jerry
Silver Member
Gary, I checked my BD with Datsun(mitsubishi alt) and I got 7 volts on the N, 3 something on the F. This gave me 14volts +/- a few tenths out. I forgot that there is a ground wire connected to the alt. on mine, the body of it.
Let us know of your progress.
Jerry
Let us know of your progress.
Jerry
Hello All:
Just a quick update. I purchased a new alternator and regulator (1972 Datsun 510 - NAPA part numbers AL231 and VR521SB) and had the same problem with instrument lights blowing when turning off the ignition switch even before ever cranking the motor. The running voltage also ran around 16 volts. All of my wiring matches the schematic in the manual so I believe that my wiring pattern in the six prong plug to the regulator must be different.
Rather than spend any more time and money on this I installed a one wire alternator and every thing is working fine. I did not remove any of the original wiring harness and used the existing positive and ran a new ground wire.
Even though we were unable to solve the problem I would like to thank every one for their help and think this is a great forum. Thanks Gary
Just a quick update. I purchased a new alternator and regulator (1972 Datsun 510 - NAPA part numbers AL231 and VR521SB) and had the same problem with instrument lights blowing when turning off the ignition switch even before ever cranking the motor. The running voltage also ran around 16 volts. All of my wiring matches the schematic in the manual so I believe that my wiring pattern in the six prong plug to the regulator must be different.
Rather than spend any more time and money on this I installed a one wire alternator and every thing is working fine. I did not remove any of the original wiring harness and used the existing positive and ran a new ground wire.
Even though we were unable to solve the problem I would like to thank every one for their help and think this is a great forum. Thanks Gary