Is it possible for an AMP gauge to only work on one side of 0. My gauge has never shown a charge but shows draws when there is a draw. My mechanic says the third brush is set to 4amps and works fine on the bench but nothing is showing on the gauge. Any ideas? Don.
Take that one out, shake it to see if the pointer freely moves into the charge range. If not try banging it on a bench to free it up or jar loose a possible obstruction,
OR just try a different gauge!
Reverse the gauge connection, test run, then return the connection.
One quick test you can do is to swap the wires on the back of the ammeter. What was a draw before will now be indicated as charging. That will tell you if the meter needle is capable of moving to the charging side.
The meter movement is very simple. The needle shaft has a vane on it that aligns itself with the magnetic field produced by a few loops of copper wire.
All answers so far to your question are wrong and none of them will correct this problem.
This is a common Model T wiring problem. Fixed a problem just like yours last week:
There is a charge and a discharge circuit in the Ammeter wiring and they are commonly screwed up giving you the exact results you describe.
Give me a call tomorrow 10AM to 4PM (I will be away from 12 noon-2PM) and I will walk you through two simple tests taking five minutes to conduct to determine the trouble and work with you to correct the wiring mistake.
Send me an email in advance and I will forward you a CORRECT!!!!! Model T wiring diagram so we can work together with a common frame of reference to correct this problem.
For the love of God, do not refer to it as an amp gage on this forum. The T police will instantly condem you for not calling it the proper, "amp meter".
Been there, done that.
I would suspect that the cutout on the generator might be defective. If so, you should fix it before you drive any farther or you run the risk of destroying the generator. You can test the ammeter by connecting one side to the battery and put a light bulb to ground on the other side. It should read discharge. Then reverse the connections and it should show charge. If so, your ammeter is OK. I have a feeling that your ammeter is not in the circuit. Maybe one side is connected to the battery and the other side to the lights but the wire from the generator could be connected to the same side as the battery so that the generator is charging the battery, but not going through the ammeter.
Don, I don't believe any of the answers above are "wrong" but would only give you some indication of the meter function , depending on the result you may need to check your charging circuit.
This happens to me quite often when first starting the engine. I just momentarily jump across the cutout terminals to kickstart the generator and then the ammeter needle shows it charging. Its simple to try. Tom
Actually, I believe it is "ammeter", but I'm not one of the ones who gets anal about it.
The ammeter on my 26 shows a jerky charge sometimes when running. But sometimes it is steady. I rechecked the generator operation on my bench testing machine and it shows a rock steady 8 amp charge. Bad repo ammeter? Thanks Les
Worked with Don today.
Both the charge and discharge circuits on his car are wired correctly.
The ammeter shows a charge when the cutout is shorted across. Don is getting a new cutout.
Ron really came thru for me. He is very exacting in his questions to diagnose a problem.Got me squared away and now just waiting for parts. Snyders sent an email a while ago and said its shipped already! Thanks Ron!! Don Lyon
Several years ago Ron US mailed me a wiring diagram. That and his phone counseling helped me resolve a charging issue.