Voltage Regulator location??????

[sgtrisk]

Okay, I'm old, but not completely senile!!

I've looked all over the truck and can NOT locate the voltage regulator!! I can't find anything that looks even remotely similar to the diagrams in the TM, let alone in the right location.

My problem is the charging rate (generator gauge) has been fluctuating between the yellow area and the "correct" location in the green. This is not a rapid fluctuation. Often when I start the truck the gauge will read in the yellow. After I've been driving for just a bit it will kick up into the green and stay there. Yesterday it never popped back into the green, even after multiple stops and starts.

A diesel mechanic friend, prior Marine Corps soldier, told me I should check the connections at the voltage regulator. Seemed logical.

But I can't locate the silly regulator!!

This is a 1972 M109A3, LDT465-D1 engine. It has the ether start canister installed. I'll take pics later, if requested.

Tanks!!

 

[doghead]

If you have an alternator, the regulator is internal.

If you have a generator, the regulator is a large black box near or on the firewall.

 

[stumps]

The problem you are describing is classic for bad brushes in your alternator.

-Chuck

 

[sgtrisk]

duh. I knew that!

I'll go double-check.

So now I'll throw this out: assuming that it is an alternator, if it isn't charging properly, any way to repair that, or am I most likely looking at replacing the alternator?

 

[sgtrisk]

Brushes sound like an easy repair, if I'm not mistaken.

 

[sgtrisk]

Here's what I got. I couldn't tell right off whether it's a generator or an alternator.

 

[doghead]

You have an alternator.

 

[sgtrisk]

What a silly boy I am!!

Anyone have any links for parts and/or 'structions for replacing brushes? I think I was just reading a post from last year that had some tips on testing them. But you guys probably have that information at the tips of your fingers!

Thanks for educating me!!!

 

[doghead]

There should be a TM for the alternators. I'll look for the number, I think I have it saved on my computer.

Look for TM 9-2920-225-34 and TM 9-2920-225-34P in the resources(TMs)

 

[bigmike]

Mine just started to do the same thing although last weekend it started climbing into the red until i turned on the lights and it jumped back down to green. Mine also goes to yellow then back to green when driving for a while.

Is running in red considered brushes still? I'm thinking regulator...

 

[stumps]

The alternator stops putting out power whenever the brushes stop making contact with the field's slip rings. PERIOD.

The brushes have a spring that puts them in contact with the slip rings, but they also have a wire that goes taught when the brushes wear out. That wire prevents worn out brushes from making good contact with the slip ring some of the time. The alternator will come on, and go off, and back on, etc... That corresponds to green, yellow, green, etc.

When the regulator goes bad, usually it stays bad.

-Chuck

 

[sgtrisk]

Anyone have any idea where I can new brushes? I've not had too much success with my google queries.

Tanks!