|Posted: Sat Jan 29, 2005 1:45 am Post subject: Please help me with a 1960's GM Delco 10DN Alternator & exte
|I need some help on a GM charging system, being used on an old Allis
Chalmers FP40 forklift. The Allis uses an old Delco Remy 10DN
alternator, which has an external regulator. The wiring harness and
original electro-mechanical regulator were torn out by vandals.
The local NAPA store sold me a replacment for the electro-mechanical
relay; it uses electronics instead of the old 2 small relays. It looks
the same as the old one, and has the familiar 4-conductor plug with
it's terminals labeled "F", "2", "3" and "4". The regulator is sold by
NAPA as their "MPE VR142SB", and stamped on the regulator case is:
"VR103PS" and "12V281 U.S."
Here's what I'm pretty sure is usually true on these GM systems, please
1. Wire the Regulator terminal "F" to Alternator terminal "F".
2. Wire the Regulator terminal "3" to the +12V power distribution
terminal; "3" is the "Voltage Sense" that controls the amount of
voltage the Regulator produces on it's "F" Field terminal.
I have some questions about the regulator wiring:
1. I have seen engines where Regulator Terminal #2 was connected to
the alternator's "R" terminal, and some where BOTH these terminals were
left empty, not wired to anything. What is the difference between
connecting those terminals, and leaving them unwired?
2. I am pretty sure that 1 connection to Regulator Terminal #4 was
through the "Alternator" panel lamp to the keyswitch's "Ignition"
terminal. I believe that there's usually a second wire connecting
Regulator Terminal #4 to the keyswitches "Accessory" terminal. I've
seen this second wire done two ways: either just a regular wire, or a
special "resistance wire" that has about 8 to 12 ohms of resistance.
When is it necessary to use resistance wire, versus regular copper?
Is the resistance needed only for the old electro-mechanical
regulators, or is it still needed on the new electronic regulator?
I've always thought it was for current-limiting the Field output of the
regulator, but I'm not sure.
Thank you VERY much for your time and assistance!
I thank you, and my spinal column thanks you (my back *loves* my