1086 batteries loosing charge

don rush · Nov 25, 2009

I have a 1086 W/cab that the batteries are loosing their charge after sitting for a couple of days.

The batteries are new and I have had them checked.

Any ideas are reccomendations?

karl f · Nov 25, 2009

check for a draw somewhere. could be alternator regulator, cab relay, radio, lighter socket shorted to ground.

to check for a draw you put a test light in series with the positive cable and the battery and start turning off things or pulling fuses until the light goes off. details in the archives.

karl f

El Toro · Nov 25, 2009

I would second the alternator's regulator if you have an alternator. Hal

pete 23 · Nov 25, 2009

Just to add, when checking for draw with test light, as this model uses two 12 volt batteries hooked parallel, you need to unhook other battery also and then test at eiether one.

Brownie 450 · Nov 26, 2009

Like Hal says, disconnect the 2- wire plug-in on the alternator first--easy to do. Second, take the main terminal[hot lead--large wire] off also. This will isolate the alternator. Could be a diode in the rectifier bank is shorted, or even the radio suppression capacitor shorting. Then go to the fuse removal thing.

El Toro · Nov 26, 2009

You may be able to install a master switch in the
ground cable as this will isolate the batteries from ground and prevent the batteries from discharging. No one will be able to crank the engine and the military has used this for years.
You would need another short battery cable to connect the switch to ground and hook the existing ground cable to the other terminal
on the switch. Hal

don rush · Nov 28, 2009

Thanks to all that replied. My problem was the 2 wire alternator plug. I recently changed the alternator and batteries and the plug had no markings or anyway to show the correct way to plug in so I had reversed it when I put it in the alt.

Thanks again everyone.

MERRY CHRISTMAS TO ALL!

pete 23 · Nov 29, 2009

Good to hear you found the problem. One of the things I do when I assamble one of these alternators is to check current flow through the field circuit. If you have an alternator with the internal resistor autos use for the tellite, you will get a current flow through the number one terminal with out voltage applied to number two, however, if you have the alternator normally used on tractors, you will not get any flow through field until you apply voltage to number two terminal to turn the regulator on. That is why some vehicles will run the battery down if wires are reversed and others won't, although if reversed your voltage regulation will be affected. I no longer have a test bench to test alternator output until I mount in on tractor so this is just an indicator for me that I do indeed have basic exciting circuit that should work.

1086 batteries loosing charge

don rush

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karl f

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El Toro

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pete 23

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Brownie 450

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El Toro

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don rush

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pete 23

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