The Stovebolt Site Forums The Shop Area The Electrical Bay 1951 6V Generator question

My '51 generator is not charging.

I have 2 posts on my generator. With truck running, both posts at generator have 0 Volts when checking to ground.

My voltage regulator has 5.5V at the left terminal, 0V on the right and middle. I believe the right post is the F terminal, and the middle should be the B+ coming off of the generator?

Thanks in advance,
Keith

the left post is BATT, middle is GEN [or ARM], right is Field .... the shop manual has info for the charging system, and there's a pamphlet all about it

Bill

Start out by "polarizing" the generator. Take a short jumper wire and touch it to the Bat and Arm terminals on the regulator quickly, about 1/2 second or so. A pretty good arc is normal. This puts a weak magnetic field in the generator housing and makes it produce about .5 volts DC at the Armature terminal. This voltage is sufficient to energize the field coils which find a ground at the regulator and increase the strength of the magnetic field in the generator housing. If the regulator is working properly, the voltage should rise to around 6.5 volts and close the set of regulator points behind the Bat. terminal.

If the generator cannot be polarized, you probably need some repair/rebuilding work done inside the generator. If the generator produces the .5 volts at the armature terminal after polarizing, but will not go higher, try cleaning the regulator points with a piece of clean index card stock or a business card. (No filing or sandpaper!) Disconnect the BAT wire at the regulator first, to avoid shorting anything out while working on the regulator. Good luck!
Jerry

Thanks-this is what I was leaning toward. This should be done with the engine running-correct?

This truck has been sitting since 1981 so I am wondering if the "field" was lost while it sat..

Thanks,
Keith

before starting the engine

Bill

Running- - - -not running - - - - -doesn't really matter. I've done it both ways for over 50 years with no noticeable difference in the results- - - -it either works or not depending on the internal capability of the generator. I am partial to using an "analog" volt/amp meter, (with a sweep needle) as some digital meters respond too fast for a vibrating contact regulator and just end up indicating gibberish instead of a usable indication of current or voltage.
Jerry