Electrical gremlins

[wcmill]

Gentleman, having a electrical issue that’s driving me crazy. I have a Powerhouse gen on a 31 roadster. The gen passes the motoring test but seems to turn slowly.
Cutout is old school. The gap checks out and seems to close at around 7 volts.
The car starts and runs fine….very well even. But when I try to get a voltage reading either directly from the battery or from the starter while the car is running the reading is all over the place. Mostly it doesn’t even register….like an open circuit or short. When a number does pop up it’s anywhere from 6 volts to 12 to 2 or 1 etc. Then mostly it just freezes the meter or shorts to open. I’ve tried 3 different meters with the same results…..I’ve also bypassed the cutout, and disconnected the output wires entirely from the cutout, but with no change.
The second you shut the car off, the reading changes to normal battery voltage regardless of where it’s taken from…start it back up and the problem re occurs.
WHAT COULD THIS BE!!
It’s acting like it’s creating a electrical or magnetic disturbance the second you start the car. Theses no change when turning on or off the ignition switch when the engine is not running…..again, just with the engine running.
Could the gen be shorting to ground? Coil? Points? But the car starts and runs fine.
The car has a master on/off switch, the ammeter needle is broken off but it has continuity and is connected. Ignition switch is not grounded to the frame….not sure if it has to be. It’s just dangling as I’m waiting for a new instrument pod.
Sorry to ramble on…hopefully I explained it well enough.
Any help here would be greatly appreciated ….

Cheers

Wade

[bobv]

Digital or analog test meter? They don't much like the digital meters.

[nkaminar]

Digital meters will sometimes be fooled by radio interference, which can be caused by the ignition or by the generator. Try running the engine for a short time with the fan belt off and measuring the voltage then. Also, measure the battery voltage right after the engine is turned off, it should be about 6.4 volts if it was being charged.

Install a new ammeter and use that to tell if your charging system is working correctly.

It could be that you are overthinking this. If the car is running fine, as you say, and starting easily, then things are as they should be.

Check your electrical connections and ground connections. It could be a loose connection somewhere.

[eagle]

As said above, its the "noise" from the generator messing with the digital voltmeter. Use an analog meter, or just check the voltage when the car is off. If it stays up whereit should be then you know its charging. Get an original ammeter and replace the broken one, most of the repops are no good.

[wcmill]

Thanks guys…..the analog multimeter makes sense to me, don’t know why that didn’t cross my mind.
Hopefully it’s something simple. Oh well, off to buy another multimeter. Guess it’s good to have an analog one for these cars anyway.
I will post the results.

[wcmill]

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Who carries original ammeters? I couldn’t find one.

[Patrick L.]

What the fellas said about an analog meter.

What does the ammeter show ? If it shows a charge it should be good to go. The third brush is adjustable so the charge rate can be adjusted.

[wcmill]

Originally Posted by Patrick L.

What the fellas said about an analog meter.

What does the ammeter show ? If it shows a charge it should be good to go. The third brush is adjustable so the charge rate can be adjusted.

The ammeter is broken, needle broke off, as mentioned it is connected and has continuity. Waiting for new one to arrive.

[Badpuppy]

You should be able to get a reliable reading by measuring directly across the battery posts. The battery acts like a giant smoothing capacitor to absorb spikes and interference.

[nkaminar]

Analog voltmeters are on ebay starting at about $10. Might check amazon too.

[rotorwrench]

I would recommend looking for a late Auto-Lite type generator unless you want to try to correct the problems there may be with the powerhouse generator. The powerhouse has a fragile brush holder ring that can fall apart just by removing it depending on condition. The little parts that hold the brushes to the Bakelite ring can be loose and cause intermittent function. Tom Wesenberg had a fix for this by soldering parts together. If he was still around, he'd be the first one to tell you what to check on these. His posts are still on here if searched out. They are good generators but they are a bit complex when compared to the cylindrical types. A 1931 vehicle would have had the late type anyway and they are a lot easier to overhaul. There are a lot of parts out there to support them as well. The powerhouse type, not so much.

[ronn]

make sure your ammeter posts arent rubbing on the dash/tank

[wcmill]

Originally Posted by rotorwrench

I would recommend looking for a late Auto-Lite type generator unless you want to try to correct the problems there may be with the powerhouse generator. The powerhouse has a fragile brush holder ring that can fall apart just by removing it depending on condition. The little parts that hold the brushes to the Bakelite ring can be loose and cause intermittent function. Tom Wesenberg had a fix for this by soldering parts together. If he was still around, he'd be the first one to tell you what to check on these. His posts are still n here if searched out. They are good generators but they are a bit complex when compared to the cylindrical types. A 1931 vehicle would have had the late type anyway and they are a lot easier to overhaul. There are a lot of parts out there to support them as well. The powerhouse type, not so much.

Thanks for all the info….got an analog meter and it read no problems at all. So that was it. Bad news is the gen isn’t working. Measured after the cut out and then bypassed it…..nothing.
It does motor when you apply power and remove the belt, but it barely turns and you always have to give it a spin to get it going.
I think I’m done messing with the powerhouse. For all the reasons you mentioned and more.
I’ve read hours of Tom’s posts here on this forum…..pure genius.
I can see now why he is so missed.

[wcmill]

One more thing before I throw in the towel on the powerhouse. Is the field terminal that comes out of the gen body supposed to be isolated from the body itself? I have continuity from the terminal to the case or body.
Obviously my strong point is not 6 volt electrical ☹️

[midgetracer]

The field terminal should be isolated from the body. The continuity may be from the assembled generator. The terminal is definitely insulated from the case.

[wcmill]

So possibly my issue? Could be 50 other things too……but have to start somewhere.

[rotorwrench]

The early five brush units are more complicated due to the two extra brushes. The power brushes are connected together with the output wire bridge piece. The three brush units are more simple to work with. I've seen five brush units that were converted to three brush before. The three brush has less to go wrong. The six field coils are basically the same between the two types but have differences in the wire and windings which affects the Ohm readings and amount of current it will draw when power is applied to it. The armatures are also the same basic design. Tom and others pointed out the differences in older posts on the subject.

I've been looking for an internal wire diagram for the powerhouse and still haven't found one. My model a generator manual has everything but. I haven't taken one apart nor retaped the field coils yet so I don't know how they are wound but it would be interesting to know. A generator won't motor near as fast as an electric motor since it isn't designed as a motor. It may have a dead segment in the commutator or there is an open somewhere in the armature or field. A cross short in a field or armature coil will take away it's capability a good bit since it may be bypassing a good bit of the circuit pathway.

[wcmill]

Thanks Rotorwrench. Again all good info. I’m torn because I’d actually like to keep the Powerhouse even though it’s not correct for my model year. From all I’ve read, they’re supposed to be a good higher quality generator. As others have said however, scarce parts, more complex and not much support.
I’ll mess around with it for awhile, I’m in Canada so still a few months away from driving season.
2nd try will be for the more common style auto-lite followed by a 6 volt positive ground alternator. Not really my desire though as I’d like to keep a gen in it.
Do you or others know what I would need exactly for a gen that would bolt right in as far as a 1931 goes?
The only real difference I’ve found is what they call a short or long body….or snout. Would either one of these work ok? Other then the size what were the other differences between the two?

[rotorwrench]

The shorter front shaft taper and bushing type bearing design is correct for the 30 & 31 models for the most part. This type was the end replacement for all the earlier types but any of them will work. Many model As were still in service even after the war so a lot of older generators were replaced with later types or updated earlier types. Rebuilders used whatever parts were available to get them back in service.

[wcmill]

It looks like the mounting brackets are different from the powerhouse.
Will I need to do any mods to install the correct or non Powerhouse gen? Or should it bolt right in?