6v Alternator

D

DBSHELTON

Senior Member
I converted a GM alternator to 6v positive ground with a kit. Installed it on my 29 Tudor. You have to rev the engine to excite it to charge. Is this common?
 
Mine too, that's normal. You can rev it when you start up, or you can just let the car run off battery for the first few minutes until it kicks in on its own.
 
I think that Is the way they have to be excited to start, Certainly no big deal once you realize what you have to do. It becomes instinct! .
 
Thanks, I figured that was the case, just wanted other opinions. The alternator in my other Model A seems to have a lower cut-in point but that may be due to the little-bit smaller pulley.
 
When you use the small diameter pulleys on an alternator, you will get better belt grip on the pulley, without a lot of belt tension, if you use a fan belt with the little V-notches in it on the inside surface.

Example:

high-capacity-v-belt-1-top-r.jpg


The exact belt you get will depend on the circumference you need for your engine setup. I don't want to quote a belt number and have it be wrong for your car. Work with your parts supplier.

.
 
The alternator needs a small current flow through its field windings to start. The starting current in a modern car occurs when the charging light goes on as the car is started. I have an alternator in my Coupe that does not self start and requires revving the engine. To the contrary, I have a Nu Rex alternator in my Victoria that self starts. So there is a way of making your alternator self start, but I am not sure to do this.
 
You can add an exciter wire to the 2wire plug-in, no.1 is excite term no.2 is voltage sense. Add a wire to no. 1 run into cab, by momentarily ground wire alt will start charging. Or you can add a resistor inside of alt to help turn on faster. There are several ways that will help.
 
Best I have found is to not worry about it. I just drive slowly up the street and by the time evrything is starting to warm up it is showing a charge.

I now have a PowerGen and it does not have that non-issue. It charges right from the get-go.
 
And I thought it was notched for cooling !!
You ever consider writing a book -- for those's of less common sence, such as myself?


Example:

high-capacity-v-belt-1-top-r.jpg


The exact belt you get will depend on the circumference you need for your engine setup. I don't want to quote a belt number and have it be wrong for your car. Work with your parts supplier.

.[/QUOTE]
 
rfitzpatrick said:
And I thought it was notched for cooling !!
You ever consider writing a book -- for those of less common sense, such as myself?
Click to expand...

I'm glad you find my little tips helpful.

I do not plan to write a book. I have been writing "Jim's Tech Tips" monthly for MAFCA for a couple of years now. They include it in a monthly email blast that they send to Members, and in another monthly blast to all of the Chapter newsletter editors, for clubs to put in their newsletters.

If you want to get the email blast each month, send your email address to modelagarth (at) yahoo (dot) com

.
 
I went ahead and installed a momentary switch to ground on the #1 terminal. Now one touch and it is charging. Makes me feel better anyway.
 
Jim/GA said:
When you use the small diameter pulleys on an alternator, you will get better belt grip on the pulley, without a lot of belt tension, if you use a fan belt with the little V-notches in it on the inside surface.

Example:

high-capacity-v-belt-1-top-r.jpg


The exact belt you get will depend on the circumference you need for your engine setup. I don't want to quote a belt number and have it be wrong for your car. Work with your parts supplier.

.
Click to expand...

Yep, that would be your BX40 or slightly larger BX41. This is known as a cogged belt.
 
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