More powerhouse issues??

[wcmill]

Hey guys….I’m still trouble shooting my Powerhouse gen.
I understand there should be no continuity from the terminal wire or post that exits the gen body to the case itself. But mine does.
I removed that wire from the adjustable brush…..it’s a 3 brush unit, and there is no short or continuity. There is however continuity from the field coil wire to the case……is that normal or should that wire also be isolated?
In other words, my ground from the terminal post to the case is happening because the field wire that attaches to that brush obviously touches the commutator which will have continuity to all the brushes. (Hope that makes sense)
Is my thinking correct on this? As long as the field wire is grounded to the case, so will the terminal wire by association through the commutator.
So I’m thinking the field coil wire should not be grounded to the case, mine is.
Heads spinning….

 

[Kurt in NJ]

powerhouse generator—-
should “motor” at 2.5-3 amps
the field should take 2 amps at 6V, one end is connected to third brush, other end grounded to case.
brush spring tension- 12-16 oz

 

[Joe K]

Image showing the Model A Ford Wiring Diagram. Note particularly the detail for the generator

Note also that one end of the field wires is "grounded" to the case.

Your "powerhouse" generator may include more "poles" but there will likely be but one wire passing through all the pole pieces and coming to a "landing."

A check of the poles is done by removing the ground connection, and then using a VOM/Continuity Tester to see if there is a ground then (i.e. field coil shorted to the case.) There should be no ground.

This failure is not uncommon. Between motion of the coils on the pole pieces due to windage or magnetism, or just normal "wear & tear" and aged wire coating a short in this area is common.

Joe K

 

[wcmill]

So electrical is not my specialty. I just can’t get my head wrapped around my initial question. Although I appreciate your help you guys.
If everyone says the terminal shouldn’t be grounded to the case, but the field coil IS on one end grounded to the case that would make the other end grounded as well wouldn’t it? Then if this wire is connected to a brush the brush touches the commutator……yes?.?? In turn this also then grounds my output terminal to the case……
What am I not seeing here???

 

[wcmill]

So one thing I just discovered while looking at pictures of the powerhouse. Which wire is attached to the adjustable brush on a 3 brush gen?
My adjustable brush is connected directly to the output terminal on the generator. But it looks like the field coil wire should be attached to the adjustable brush???

 

[rotorwrench]

The 3-brush unit has a ground path on one end of the field coils while the other end is connected to the 3rd brush. The armature unit's power output brush is connected to the cutout. The other armature unit brush is connected to the ground.

On a five brush unit, it still works in the same fashion but it has two power output brushes and two ground brushes. The field brush is still connected to the armature commutator so it is still acting like a 3rd brush in a 3-brush type unit to control the output through the magnetic field strength. This is a redundant system and Ford eventually discontinued it in favor of a 3-brush design.

 

[wcmill]

Sorry for the terminology here………so the “third brush” is the adjustable on the powerhouse …I know it’s defined as that on the autolite gens.
Just want to be clear that the field coil wire is attached to the ADJUSTABLE brush.
Apologies again If this is basic 101 stuff……..foggy brain this morning

 

[katy]

Disconnect the field wire that goes to "ground", disconnect the other end of the field windings that connects to the "third brush". Then "megger" the field windings, should read infinity. A lot of problems on old generators are that the field coils have deteriorated and that does not show up with your typical multimeter.

https://en.wikipedia.org/wiki/Megohmmeter

 

[rotorwrench]

The field coils will have an several Ohms depending on type but most folks check them by determining how much current they will draw from a 6-volt power source. That gives a better test than an Ohms test.