340 U Alt. wiring

Anonymous-0 · Feb 27, 2009

I checked the wiring on alt. One wire going from bat. post on alt to #2 terminal on alt. Another wire on bat. post on alt goes to oil pressure sending unit then from oil pressure sending unit to #1 terminal on alt. Bigger wire from bat. post on alt. to harness . I've been reading on some 6-12volt conversions on this site and it seems I need a diode.This is my question.If I run a wire from + terminal on coil to #1 terminal on alt. with a 1n4004 diode in it which way do I want the current to flow? To the alt. or to the coil. Can I put a switch in this wire until I get the diode? Thankyou for your time and help. Al

JMOR · Feb 27, 2009

(quoted from post at 09:47:55 02/27/09) I checked the wiring on alt. One wire going from bat. post on alt to #2 terminal on alt. Another wire on bat. post on alt goes to oil pressure sending unit then from oil pressure sending unit to #1 terminal on alt. Bigger wire from bat. post on alt. to harness . I've been reading on some 6-12volt conversions on this site and it seems I need a diode.This is my question.If I run a wire from + terminal on coil to #1 terminal on alt. with a 1n4004 diode in it which way do I want the current to flow? To the alt. or to the coil. Can I put a switch in this wire until I get the diode? Thankyou for your time and help. Al

Al, perhaps you had an earlier post that I missed, but are you having some kind of malfunction? Or did you just read that maybe you need a diode?
Without further info, I assume that there is no malfunction. If that is the case, then I expect that you do not need a diode and the the item you ID as oil pressure sending unit is actually an oil pressure switch AND the it turns off alternator excite current when there is no oil pressure. If there is a problem & it keeps on running when you try to kill it, then you need to add the diode (band toward alternator) in the #1 (excite) line. Yes, a switch is an OK temporary measure, or just un-plug the connector in alternator at end of use for the day. I only answered you because no one had for several hours & maybe someone with a 340 can/will be more specific.

tooltimejim · Feb 27, 2009

hi, i did the same to my 340u. i ran a radio shack diode inline from # 1 on alt, to load side of ignition switch/u could as install a idiot Light between #1 on alt and load sie of ign.
18 ga wire was used
hope this helps Jim

Anonymous-0 · Feb 27, 2009

Problem is batt. drains overnight .I've had this tractor about 5 yrs and I usually unhook bat. cable when not in use.not really sure if alt has a bad diode in it.

TractormanNC · Feb 27, 2009

The other red (Massey) used this setup for years, works fine. I think you have other problems inside the alternator.

JMOR · Feb 27, 2009

The external diode you mention in the excite line isn't very likely to help your battery drain problem. As you suggest it is likely a rectifier or the internal regulator itself. Take it to alt shop or parts store for a free test.

340 U Alt. wiring

Anonymous-0

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JMOR

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tooltimejim

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Anonymous-0

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TractormanNC

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JMOR

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