Generator connections 55 F100

[tommyleea]

I received my new 12 volt generator. I am switching from 6 volt to 12 volt. The connections look the same, but they are not marked on the new generator. Would they be the same as the 6 volt was? If not how would I determine what is what? Thanks.

[big job]

In general I would say yes the big terminal 'fat wire' goes to 'ARM' on the regulator
most will have two small terminals one is ground goes to regulator mounting screw the
other small terminal is field goes to 'F' (field terminal on the regulator) . On the generator
look closely at the field terminal it is isolated you should see a non metalic washer probably bakelite insulator. There should be an F stamped near this terminal. You
may have to polarize before starting .... sam

[tommyleea]

Originally Posted by big job

In general I would say yes the big terminal 'fat wire' goes to 'ARM' on the regulator
most will have two small terminals one is ground goes to regulator mounting screw the
other small terminal is field goes to 'F' (field terminal on the regulator) . On the generator
look closely at the field terminal it is isolated you should see a non metalic washer probably bakelite insulator. There should be an F stamped near this terminal. You
may have to polarize before starting .... sam

Thanks I will look for the isolation washer. There are no markings to identify the terminals. It does say to polarize initially. I guess the ground and field are the ones that I am concerned about. The stud on the back, I assume, would be the armature connection.

[Herman Munster]

I don't know if it'll make a difference but the 55 was positive ground and 12V were negative ground.

[dmsfrr]

Originally Posted by tommyleea

I received my new 12 volt generator. I am switching from 6 volt to 12 volt. The connections look the same, but they are not marked on the new generator. Would they be the same as the 6 volt was? If not how would I determine what is what? Thanks.

The '55 Bird I have was converted to 12v before I got it and the charging system worked fine. I took 'before' photos of wiring in anticipation of putting it all back together after replacing the engine.

The Field and Ground terminals on this 12v generator are also not marked. So I traced the wire colors back to the voltage regulator to confirm the connections. I double checked by looking for other diagrams and photos. There is a diagram on pg 7-7 of a '57 shop manual that shows the Field and Ground terminals in the same locations on the generator as the first photo below.
When I reconnected it all after the new engine I 'polarized' the generator and it's been working fine.

Electrically the unmarked F and G terminals may be functionally interchangeable (possibly the reason they aren't physically marked F or G ???) The process of polarizing the generator apparently takes care of it... but that's just a wild guess on my part at this point.

~ When you're done reconnecting the wiring, before you start the engine, remove the Field wire from the voltage regulator and quickly touch it to the Battery terminal of the voltage regulator. You will get a small spark and it will Polarize the generator. Then reconnect the Field wire to it’s position on the voltage regulator. ~

[tommyleea]

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Originally Posted by dmsfrr

The '55 Bird I have was converted to 12v before I got it and the charging system worked fine. I took 'before' photos of wiring in anticipation of putting it all back together after replacing the engine.

The Field and Ground terminals on this 12v generator are also not marked. So I traced the wire colors back to the voltage regulator to confirm the connections. I double checked by looking for other diagrams and photos. There is a diagram on pg 7-7 of a '57 shop manual that shows the Field and Ground terminals in the same locations on the generator as the first photo below.
When I reconnected it all after the new engine I 'polarized' the generator and it's been working fine.

Electrically the unmarked F and G terminals may be functionally interchangeable (possibly the reason they aren't physically marked F or G ???) The process of polarizing the generator apparently takes care of it... but that's just a wild guess on my part at this point.

~ When you're done reconnecting the wiring, before you start the engine, remove the Field wire from the voltage regulator and quickly touch it to the Battery terminal of the voltage regulator. You will get a small spark and it will Polarize the generator. Then reconnect the Field wire to it’s position on the voltage regulator. ~

Ok..Thanks for the picture. That is the way my current 6 volt is set up, so it is the same. Also, looking at mine, I see the field terminal does have an isolation washer on it.

[paul2748]

Looks like you have the sedan back plate on the generator

Originally Posted by dmsfrr

The '55 Bird I have was converted to 12v before I got it and the charging system worked fine. I took 'before' photos of wiring in anticipation of putting it all back together after replacing the engine.

~

[dmsfrr]

Originally Posted by paul2748

Looks like you have the sedan back plate on the generator

You are correct, that's the way it came from the previous owner. I do have the alteration kit that moves the armature stud lower, away from the front edge of the head.
Fyi, the generator does have the correct T-bird belt pulley on the front and otherwise fits fine.
.

[Daves55Sedan]

Originally Posted by paul2748

Looks like you have the sedan back plate on the generator

If my memory serves me right, the 6-volt ('54/55) generators had a cast-iron backplate. The 12-volt generators (56 thru '64) had a 1/16" steel backplate.

On the T-bird engines, the generator backplate is mounted in front of the head to line up with the crankshaft damper which sticks out farther than the the car engine crankshaft damper. The car engine generator is mounted alongside of and below the head and the top mount and adjusting brackets are different between the T-bird and sedan.
The top "swing-bracket" fits between the front and back mounting plates of the generator so that no matter if the generator is 6 or 12 volts, the same swing-bracket can be used.
But on '56 and later T-birds, the thinner backplate would tend to pull the front of the generator back about 3/16 of an inch, unless they made it up by having a boss cast in to the block or added that much washers to push the generator out so it's pulley lines up with the crankshaft damper.
On the '56 car engines, the loss of 3/16" in overall length of the generator is of no consequence, since the backplate hangs off the back of the swing-bracket. Those backplates could be any thickness you wanted and all you would need is a longer bolt to go thru the swing-bracket.
Why did they change from a cast-iron backplate to a stamped steel backplate? The 6-volt ('54/55) cast backplates had an oil/bronze particle bushing. In '56, they had a roller-bearing inside the hub of the stamped steel backplate instead. Big improvement.

[paul2748]

I had the same things on my 56 when I got it. Luckily, a local generator rebuilder had the Tbird front pulley in his storeroom (this was in 2006). I bought the alteration kit from CASCO and changed it.

Originally Posted by dmsfrr

You are correct, that's the way it came from the previous owner. I do have the alteration kit that moves the armature stud lower, away from the front edge of the head.
Fyi, the generator does have the correct T-bird belt pulley on the front and otherwise fits fine.
.