Ammeter

Dtolson

Dtolson

Member
On my 28 CCPU. The battery was dead the other day. I noticed the water level was down in the battery and I added 12 ounces of distilled water. The battery took the charge and is holding. I drive it about 39 miles today and kept an eye on the ammeter. It stays on 0 the entire time unless I turn the lights on or honk the horn. Is this normal? Could the low water issue caused my dead battery? I have a 6 volt system with a generator.
 
When did this problem start ? Was anything done ? When you say the ammeter only moves when the lights or horn are operated, I think you mean discharge ? Have you tried ' polarizing ' it ? In that, while engine is running, just take a short jumper wire [or any such thing] and jump across the/both cutout terminals for just a nano-second [ you'll get just a little spark and its done]. See what that does and let us know.
 
Jump across the cutout with the engine running. (Keep away from the fan) if it shows a charge=bad cutout. Still no charge probably needs generator repair. You can drive many miles with the generator not working if you don't make multiple starts and use the lights.
 
Try reving it up a tad when you polarize. The generator needs to be above a slow idle before it will start to charge.
 
To be sure I'm polarizing correctly, I jump across the cutoff at the two wires at the forward side of the cutoff ? Sorry but I've never done this before. Also, I notice my generator does not have the band around it covering the thee open slots. It appears oily inside.
 
You need to jump a wire from one end of the cut out where the wire connects to the other end where the cutout connects to the terminal post on the generator, for a second or two. The motor needs to be running fast enough for the generator to begin charging.
 
After you jump the input and output terminals on the cutout for one second, then use a volt meter to read the voltage at the output terminal. It should read the same as the voltage at the battery posts, about 6.3 volts, or close to it. Then start the engine and run it at fast idle, and read the voltage again at both the input and output terminals of the cutout. Both sides should be reading more than the voltage with the engine off. If not, then the generator needs to be worked on.

I always use an analog volt meter rather than a digital, when working on a Model A.
 
One other easy quick things you can do to determine if the problem is cut-out or generator [ if polarizing doesn't seem to help] is to feed power to the generator and see if it tries to motor [ loosen or remove the belt so pulley turns easily]. If the generator motors then in most cases its good.
 
Hi Dtolston,

All good advice above; however, to see if your generator is charging:

1. You can use up 100 yards of wire trying to polarize your generator; and/or,

2. You can buy & try 100 cut outs to try to make your generator charge; but,

3. When you get "serious" & want to find out "if" the generator is "charging", then follow explicit instructions in reply no. 10 above from Mr. Wesenberg.

4. Get an analog multi-meter with a needle, not the digital version -- Wal-Mart has the yellow GE model in the tool department for under $15.00.

5. Place the ground wire on the generator case & the hot wire on the generator output as stated above & report back with your reading.

6. Next, place the ground wire on the engine & the hot wire on the generator output as stated above & report back with your reading.

7. If the reading when grounded on the engine is "higher" in volts, your generator is "not" properly "grounded" to the engine, frame, & your ground on the battery.

8. Strong words for emphasizing a point, but been there, done that -- this test works every time & eliminates bouncing around in circles for (3) weeks.

Sincerely hope this saves you valuable Model A time to move on to restoring something else.

Appears to always have something else to do on a Model A.

Let us know your analog readings -- someone will always want to assist.

Added Note: It is not uncommon to experience "ungrounded" generators "and" starters because of having paint on the mating surfaces where mounted. These mating surfaces should have bare metal to provide electrical continuity. Also, the rear mounting leg on the generator should have unpainted contact with the generator case.
 
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Dtolson said:
Will a 6 volt battery charger work for feeding power to the generator for that testing method?
Click to expand...

Yes the battery charger will work to motor the generator. First remove the fan belt from the generator pulley. Ground the generator with the positive cable (red) connect the ground cable to the post on the generator (black). This is important, If the generator is good, it will motor in the same direction either way but if you hook it up backwards, the generator will have to be re polarized. Model A's were originally positive ground.
 
I did the test with the meter. I got 12 on the meter by grounding at the generator and on the engine block. Bad cut out? I'm still learning so be patient !
 
Dtolson said:
To be sure I'm polarizing correctly, I jump across the cutoff at the two wires at the forward side of the cutoff ? Sorry but I've never done this before. Also, I notice my generator does not have the band around it covering the thee open slots. It appears oily inside.[/QUOTE]

That might be 1/2 your trouble right there...If you are mechanically inclined, take it apart and clean it up and get the proper band for it.

Take it to your local generator repair business and see if it is working properly.

Pluck
Click to expand...
 
Before i put all the components on my bare frame i know i will need to clean up and put contact grease on all these engine to battery ground spots. (along with any other grounding spots)

On the rear motor mounts since there's the rubber pads how does the engine actually ground to the frame? Thru those metal spacers and hoping the bolts touch it?

i know the generator mount will need to be clean and shiny.
 
SeaSlugs, the engine grounds through the front motor mount, engine splash pans, metal fuel line, spark and throttle links, and rear spring. I'm sure I missed a few more ground points.
 
ahhhh hmm i thought ive heard of running a short thick ground strap from the frame to one of the flywheel housing bolts to get a good solid ground.

i would rather not clean the paint off my AA's front cross-member that's prone to rusting for the front motor mount nor it running thru the trans gears or along the fuel line...(not saying its wrong but rather know i have the best shortest ground possible)
 
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