6 volt ammeter driving me nuts

[Phil960]

'55 960 6v 172ci
The ammeter, which is new, flutters and jumps around crazy. Then it will stop and sit still for a few seconds and then goes right back to jumping around. I've switched the wires around and back again. Doesn't matter which way it's hooked up. Currently, the hot wire is connected to the neg side of ammeter. I've searched the posts and have not found a definitive answer. The tractor is starting fine and the battery shows 6.35v post to post. I checked the wires from the ammeter and get just over 6v on my meter when tractor is off and switch is on and 0.00 when switch is off so I'm thinking the charging system is ok. Bad ammeter? Voltage reg shot? Possibly a loose connection somewhere? I'm usually a patient guy but this one is driving me insane. Any help would be appreciated. Thanks, Phil
 

[Texasmark1]

It's probably not the ammeter but the current that drives it. If the brushes in your gen are heavily worn, the springs holding them are extended and of little use in keeping the brushes in contact with the armature. This causes brush hopping which causes the current to come and go.

The regulator, if mechanical is a different critter and causes a different kind of problem.

Mark
 

[Texasmark1]

It's probably not the ammeter but the current that drives it. If the brushes in your gen are heavily worn, the springs holding them are extended and of little use in keeping the brushes in contact with the armature. This causes brush hopping which causes the current to come and go.

The regulator, if mechanical is a different critter and causes a different kind of problem.

Mark
 

[JMOR]

[john in la]

I agree with JMOR
If you get voltage at amp meter with key on and no voltage with key off you have it wired wrong. What has happened is you are running all the charging system threw the key switch and it is about to fail. These key switches are for very small loads and they still fail often.
If after checking out your tractor you find we are correct I would replace the key switch even if it still seems to be working properly.

 

[Phil960]

Ok, so the wiring is wired wrong, but where? I've had this particular tractor only 2 months and the only wiring I've changed is the ammeter itself. When I got it, the ammeter was broken and it was the original solid wire through the loop type. I did have to replace the key switch but wired it exactly as the previous one. The previous owner used the tractor on a daily basis and did not reveal any problems which of course doesn't mean much. The wiring appears original but who knows? I'd like to get this figured out before spring as this tractor is to be a working tractor. I have used it quite a bit already and most other issues have been resolved. I really hate to start throwing parts at it without knowing what is really going on. Thanks for the input. I will start a complete wiring check later today and let you know what I find. Thanks again.
 

[john in la]

While it is easy for us to pick out why you have a problem it is often hard for us to tell you the real problem since we can not see the tractor.
With the way I have seen some people wire these tractors I am only guessing. That is why I give you a diagram. You could be using the amp meter; key switch; or even a terminal block to connect wires. All will give differant problems and will change my answer.

BUT................
Lets assume we are using all the stock parts and go from there. You can see there is a wire (yellow if orginal) that runs from the starter relay to the amp gauge. This will give the amp gauge power 24/7 and you said no power with key off. Hence we know you have it wired wrong.
How it is done is the question.
You could have the wire from the relay direct to the terminal block A side and the amp gauge voltage regulator to terminal block B side. This will cause all power to run threw the key switch.

Another way of saying this is......
Look at the terminal block in the picture. The top bolt is hot 24/7 It has one side of the key; power from the battery threw the amp gauge; and the voltage regulator B post.
The other side of the terminal block only has power with the key on. It has the key switch and coil only. So the only power that is switched by the key is the coil.
 

[souNdguy]

do yourself a favor and rewire like or close to oem.. then see where you are at.

it will help us help you if the wireing circuit is functionally the same.