what is the source of the d+ alternator wire?

I'm having charging trouble with a brand new 65a alternator/

regulator, a strong optima, and all good grounds. i was thinking

about running a new d+ wire to fix the problem. does anybody

know where this wire comes from and what it measures/sends.

tia,

dewar

Is your new alternator internal regulated? If so, there is a D+ terminal on the back. You need to connect that to the blue wire from your old alt. harness. It's function is to ground the dash bulb when the alternator isn't spinning. When it spins, the current switches to 12 volts positive and makes the light go out. Test your old wiring by turning the key to the ON position without starting it and grounding the blue wire to metal. Your alt.dash bulb should light. If it does, you are good to go!

I thought it had more function than that. I already have that

hooked up properly and I tested just to make sure. My problem is

this: Whenever I turn on larger current drawing electronics

(electric fan, headlights...) it decreases the voltage from ~14 to

12-13 volts. The voltage gets low enough sometimes to rob my

coil of spark and cut out at high rpms. This doesn't seem right,

especially not on a new 65a alternator. It's working alright now

with the fan turned off, I just don't get what's going on. Any

thoughts.

thanks for your help,

dewar

when it first spins up. Sounds like your alt. is putting out charge,

so D+ must be OK. You should have you alternator load tested.

Also, the symptoms you describe can be caused by excessive

resistance, on either + or - side. Check your connections, at B+,

both battery terminals, ground between alt. and motor, ground at

motor and chassis from the battery, etc.

Chris B.

'73 ex-Malaga