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i recently picked up an 87 toyota pu, it woulnt hold a charge i have tried new batt new alt, all fuses and relays seem to be fine, i believe there is a short or bare wire somewere along the way any help on what wire would be greatly apreciative, also i checked at the hot comming off the alt, and im getting 13.9 so alt is throwing out a charge it just isnt making it to the battery
 

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Check at the battery to see what voltage is appearing there. Ohm out the alternator harness. Could be as simple as a broken wire, usually at the connector.
 

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rock crawler
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If you had a short you would have a blown fuse or some melted wiring somewhere.
If the voltage from the alt is not getting to the battery, that indicates there is an open somewhere in the wiring between the two (and the open could possibly have been caused from a previous short melting some wires completely through).

You need to start at one end and follow all the wires to the other end.

Where did you measure the 13.9 volts, at the alternator output stud or at the battery terminals?
 

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rock crawler
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OK, what did you measure at the batt terminals?

If it was 0V there is an open in the wiring between the alt and batt.

If it was a few volts lower or something, either a bad connection or something is seriously loading it down.

If you didn't measure it there at all, do it.
 

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You should be reading 14.2V at the battery terminals, so the alt ISN'T putting out enough juice. Did you meticulously clean ALL battery cables, terminals, and body/engine grounds?
 
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