Re: Alternator Bootstrap Stuff

[Heather & Jeff <hjr@buffnet.net>]

>howdy,
>here's an interesting situation:
>1. start the car, the alternator doesn't "come up." rev the engine once to
>1800......etc

Alan was mostly correct, especially about checking the idiot light first. 
 Here's some other thoughts....

If you are running a Motorola alternator, they came in two general 
flavors, 1. Ignition turn-on  2. Diode trio turn-on    Ignition turn-on 
is more common for auto applications.  When you turn the key on, juice 
flows thru the idiot light and to the field excite circuit.  However, 
most idiot lights don't have a low enough resistance to get things going, 
so often a resistor is paralleled across it.  Some designs used a special 
low resistance bulb without resistor, and if you replaced it with the 
wrong type, you get the kind of problem you mentioned.

I don't know your circuit, but could be.. wrong bulb, bad resistor, bad 
resistor connection, bad voltage regulator, bad wiring in general.

Diode trio turn-on uses the residual magnetism in the rotor to start 
things going.  Your problem mimicks a bad trio but I doubt that you have 
this type. Usually used on semi-trucks & stuff.

(Useless info for everyone else: Motorola sold the alternator biz to 
Prestolite Electric, who now brand-name the alternators Leece-Neville)

If problem persists, get me the part number off the alternator and I'll 
tell you how to proceed further.

Jeff
Director Sales & Marketing
Leece-Neville div Prestolite Electric

'88 80q