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Weird alternator/charging problems -- building a FC road race car

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Old 03-03-12, 04:11 PM
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I got it working!! Since my wiring is completely non factory the 500ohm resistor was not enough to get it down to 1-3 volts. As a test, I wired ten 500ohm resistors in series to create more resistance and got it down to 2.5volts on the L terminal. I started it up and it excited immediately! So now I need a 5,000 ohm resistor and I will be set. Thanks!
Old 03-03-12, 04:49 PM
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Glad you fixed it. Odd resistance.

The picture attached shows series FOUR arrangement. Power comes from the METER fuse (switched power) to the CPU where it goes through the ALT relays COIL (which is a bunch of resistance) then on to a blocking diode....and from there to the L terminal on the alternator.

My menory is shot I guess. I distictly remember the 500 ohm figure from probing a CPU out of the car but then I wonder if I tried to ohm thru that blocking diode which would have made a bit of a difference to the total resistance prior to the alternator terminal.

You have a series five. I know that. The L works basically the same whether four or five car.
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Old 12-19-13, 06:26 PM
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Just to close this thread as I resolved it almost two years ago. The issue was resolved by adding a 5,600 ohm resistor and dash light inline to the L wire on the alternator. My custom wiring has so little resistance that it wasn't enough to excite the alternator and turn on the regulator.

I created this resistor jumper and added in a dash light.

Resistor:

5,600 ohm resistor jumper | Flickr - Photo Sharing!

Dash light:

Steering wheel, quick release, and a proper horn button installed! | Flickr - Photo Sharing!

Works great!
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