I have a 1989 Ford F-150 6 cylinder with an alternator with and internal regulator and voltage meter. The voltage most times does not go over 10 volts, which is probably why the engine is hard to turn over when it is warm.
I have found that I can break the connection of a green wire with a connector and which runs from the alternator to the positive side of the battery circuit and then reconnect it, the battery will charge. The engine revolutions will respond (slower) to this action. Unfortunately , after I shut the engine off, I am back to low output. I have change alternators with the same result.
This truck has been "repaired" from time to time before I got it and there have been signs that those that performed repairs may have made changes. In any case, I don't know what I have.
I have downloaded a wiring diagram and I think that the wire that I disconnect appears to have a fuse and a label: "HOT IN RUN". I do not know what "Hot in Run" means and I don't find a fuse in the connector, just a connection pin and socket.
Electric theory is not my strong point. I am assuming that the green line provides power to energize something but I am only guessing.
Because there are two multi-conductor electrical plugs that plug into the alternator, I can't really analyze the circuit and I am not sure that a good connection is occurring. Is it possible to purchase replacement plugs if I suspect a worn connection?
What does Hot in Run mean? How can I analyse the charging system?
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08-25-2009, 09:43 PM
