| Re: Alternator/Isolator/Battery Problems/Questions [message #247686 is a reply to message #247658] |
Thu, 17 April 2014 06:57   |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
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One other request. If you remove the center wire to the isolator that is going to the alternator again, when you read the voltage on that disconnected wire, please also read the voltage on the center terminal of the isolator. I'm expecting it to be zero.
Another shotgun thing to check. The aluminum plate that the isolator is mounted on is suppose to be grounded direct to the engine battery negative terminal. There should be a wire (about 14 gage black) running from the engine battery negative terminal direct to the aluminum plate that the isolator is mounter on. Just check to see if it is intact.
In my previous posting I said that the fusible link was attached to the fan relay. It is really attached to the HORN RELAY. I corrected that error in my post but emailers do not get corrections.
I'm looking at the wiring diagram. I should have looked at it before I previously answered your question from memory.
The sense line to the alternator is only two wires. One wire is a 12 gage red one that is connected to the horn relay on the same terminal as the fusible link. The second wire is a white 12 gage one that attaches to pin 2 of the alternator. Those two wires are attached together somewhere between those two locations. I'm not sure where that connection is.
Forget any reference I made to other connections like switches, fuses, etc. I was thinking at the time that it might have been routed through ignition switch or something. It is not. It is a simple direct route from the horn relay to the alternator pin 2 with a change of color in route.
Realizing this, I'm thinking your sense lead problem is probably the fusible link or the connection at the horn relay. I would loosen that nut on the horn relay and clean (shine) that terminal and ALL wire connectors and then reassemble. I use stainless tooth washers and anti-oxidation grease for longevity but for now just get them shiny for a good connection.
One last comment on the generator light. Mine failed a year an a half ago. Most, not all, alternators will start just fine without that circuit. Mine does so I was in no rush to fix it. I drove it that way for about a year. When I got around to fixing it, the bulb was not blown. It turned out to be a poor (oxidized) connection at the light socket. I cleaned it with a pencil eraser.
Good Luck
Ken
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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