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Electrical issue. Alternator and Battery brand new


tres1162

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Recently my battery died, and I replaced it and got new terminals. The battery was still not charging, so I replaced the alternator. Still nothing. Then the last time I was working on it, smoke came out from the insulation of the harness to the alternator. I am now getting about 13.5 volts from the alternator, but I suspect that I am missing a fuse somewhere in the line. Let me know if I need to elaborate on the problem further.
 


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RonD

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With new battery I would expect 13.8v but could just be the voltage meter, usually voltage is 1.1v above battery voltage(12.7v new)

Assuming battery voltage as 12.4v, then 13.5v is what an alternator should be putting out to maintain the battery, and it should stay at 13.5v with lights on and heater fan on high, if voltage drops when using electrics then there is a problem.

It will go up to 14.9v just after starting the engine, this is to recharge battery after the drain from starting, but it should drop to 13.5v in a few minutes.

There are a few tests you can do with the volt meter.

Diagram here: http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_charging_1991_1.JPG
And here: http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_charging_1991_2.JPG

Engine off tests:
The B+ terminal on the back of the alternator should read "battery voltage"(12.7v with new battery), if not check Fusible links or Maxi-Fuse, follow that cable from B+ to the Starter Relay
Unplug the 3 wire connector:
Check Yellow/white stripe wire, should have 12.7v(battery voltage), check fuses if not

Turn key on
Check Light Green/Red stripe wire, should have 12.7v, this is the ON/OFF switch for the alternator
 
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