Anyone ever use the stock alternator without the relay board?, Racers? Options

[stugray]

I am guessing that someone else has tried this.

I have a stock alternator in my race car for now (upgrading to new 1-wire later). Relay board and entire harness is gone.

I know that I need the external voltage regulator, so I decided I better figure out how to wire it up...
It turns out that the plug from the Alt that goes to the relay board is exactly the same connector & pinout of the Voltage Regulator!

So it can just plug right in... not so fast.

For the alternator to startup/charge, it needs the voltage that is fed from the Alt light in the combo gauge.

SO, can I just wire in a bulb from +12V and splice it into the D+ lead on that connector where it goes into the VR plug?

Then the system should work exactly as before....??
Is the stock Alt bulb a special wattage?

Stu

[stugray]

Well it works.

I used a 70 Ohm resistor ( actually 2X 140 Ohm in parallel since high power 70 Ohm must be ordered) in parallel with the LED indicator light.

The light turns on when you turn on the ignition and goes off when the engine starts.
Read 12.4 V before start and ~13 after, but havent got the car to driving on the street yet, so I have limited info.
Since this "fix" only applies to alternator startup, I think we have it.

You could run with just the 70 Ohm resistor and no indicator if you want.
If you leave the ignition ON and the engine not running, the resistor will get hot, but not much more than the bulb (use high watt resistors).

Stu