Alt / Reg Issues (from the Merry Christmas thread)

[Brad Young]

Stu,

I have the Prestolite / Louisville Alt.
Regulator ??? I can not remember the name:  it is black with four wires coming out the back (2 yellow, 1 red and 1 black) it also has  two green wires attached internally to two connectors. I will be back on DarBay tomorrow and let you know.

things I have checked
1)I checked for loose wires did not find any.
2)Alt spun freely (bearings not fried?)
3)replaced regulator. Did not make a difference.
4)I have a inverter / charger. When I hook up to shore power. I got 13.5 v at the house bank.  (did not check the starter battery) I am not 100% sure if the inverter/charger can affect the alt or not. At some point they have to be connected. So if the Alt was shorted it would also short out the charger??

Things to do

1) I have a spare alt, will replace it  tomorrow.
2) How do you checked to see if the diodes are fried?
3) Does anyone know what type of voltage I should see at the reg?

Thanks
brad

[Stu Jackson]

1.  So if the Alt was shorted it would also short out the charger??

2.  Things to do

1) I have a spare alt, will replace it  tomorrow.
2) How do you checked to see if the diodes are fried?
3) Does anyone know what type of voltage I should see at the reg?

Brad,

1.  Nope. Two different sources of input to bank(s), one doesn't "short" another out.  JUst check the I/C charging voltage at the bank.

2.1 -- Good

2.2 -- No charging voltage when alternator is working, engine ON at more than 1500 rpm.  Buy Calder's book or take it into an auto store.

2.3 --  See Maine Sail's discussion of your Leece Neville alternator.  Most likely a tad over 14.0 or 14.2 V.

[Ron Hill]

Brad : I'd take both alternators to a "starter/alternator repair" shop and they'll be able to check both out and give you a diagnosis. 
After you know that you have a good alternator, then you can take step #2.

[Brad Young]

Sounds like a good plan. I will take both Alt to a shop. Here is a pic of the back of one of my Alt.

[mainesail]

With both your negative and hot wires black, and not clearly marked, please be very careful when you reconnect it.. This is a good example of why OCPD/fuse devices should be used..

[Brad Young]

What is OCPD?

[mainesail]

What is OCPD?

Over current protection devices / fuses, breakers etc.

[scotty]

Shows how much I know. I thought it was obsessive compulsive personality disorder.  Maybe that's just me!!