1987 MF 375 not charging batteries

denchen

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Here`s a simple drawing
alternator two wire-1024.jpg
 
  
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Overkill338

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The alternator checked out fine at the local rebuild shop.

Can.you pm me?

By the way, if you take the panel off behind the steering wheel, there is a light bulb that's burning next to the fuses.
 
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Overkill338

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Mind you don`t ground that wire when the key is on, or it will blow a fuse.
If it matters, with that wire on the alternator, it had 7 Volts on it with the key on.
 
  
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Overkill338

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Just checked. No voltage on the wire with key on
 
  
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Overkill338

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For a temporary fix, can I just run a wire from the alternator to the battery?

I ask because we really need to get this stretch of highway finished, and I can't do it without flashing lights.
 

denchen

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You could run a wire from the battery to the single terminal, but it should have a small torch size bulb in the middle somewhere. The resistance of the bulb will tell the alternator to keep charging. Disconnect the wire at the end of the day or it will run the battery down.
 
  
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Overkill338

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You could run a wire from the battery to the single terminal, but it should have a small torch size bulb in the middle somewhere. The resistance of the bulb will tell the alternator to keep charging. Disconnect the wire at the end of the day or it will run the battery down.
Any idea why this thing has stopped charging?
This terminal here. The wire that goes to it, was it supposed to have 12 volts with the key on?

20210610_112639_copy_726x1612.jpg

There is a small light that burns next to the fuses while it is running.
 
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Overkill338

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You could run a wire from the battery to the single terminal, but it should have a small torch size bulb in the middle somewhere. The resistance of the bulb will tell the alternator to keep charging. Disconnect the wire at the end of the day or it will run the battery down.
Do you mean a flashlight bulb or would an interior light bulb from a car work?

PS: Would the tractor running with the key off have cause an issue? Because that did happen for a couple minutes before I noticed it.
 
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denchen

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It needs to be 12v, and only small. An interior light bulb from a car should do the job. You might need the key on if it opens any fuel valves.
 
  
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Overkill338

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This is an 87 model. It's old school, with the manual cable fuel shutoff. If it wasn't for the city's requirements for lights, I would just finish the job without them.
It needs to be 12v, and only small. An interior light bulb from a car should do the job. You might need the key on if it opens any fuel valves.
 
 
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