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Old 03-27-2011, 11:17 AM   #7
FRED
Rotary Fan in Training
 
Join Date: Mar 2011
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Your misunderstanding me.......................the excitation power comes from the METER fuse. That power travels thru the COIL of the Alternator relay NOT thru the contacts of the alternator relay.

So now you have the alt relay in the CPU getting power on its plus side of that coil. The negative side of that alt relay coil now travels on to and thru the alternator regulator and finds ground in the alternator itself.

So the alt relay now has power on it and a ground so it pulls in and caused the Warning lights to come on on the dash.

Now you start the engine and the alternator puts out. Now what was/is the ground wire of the alternator relay has power on it that more/less matches the plus side of the alt coil so that causes the relay to relax and break the contacts that go to the warning unit which in turn makes them go out.

The warning light unit itself has zip to do with the excitation of the alternator.It's the Meter power passing thru the COIL of the alt relay that IS the excitation power for the alternator. Normally if you backprobe the White/Black wire with the connector connected to the alt and key ON........the voltage reading will not be batt votlage but approx 3vdc (bit of a voltage drop there from the batt voltage entering the alt relays coil).

I wrote too much this time.
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