Yet another 8N ammeter question. Dropping voltage

[IndianaJones50]

I have a 1950 8N, 6 volt system with a side mount distributor. The previous owner left it with the property we bought 10 years ago and it's been sitting ever since. I'm finally getting around to trying to make it run.

What I have done so far is to correct the wiring according to the many diagrams I have found posted in this forum, fixed or replaced broken splices, took apart and cleaned the carb, fixed a grounding issue in the distributor, replaced the coil and spark plug wires, thoroughly cleaned the spark plugs, verified the points are working, and a few other odds and ends. I still have the hood off, but I can now get it to turn over and run on ether.

When I began this odyssey, I discovered the terminal block on the back of the dash was completely bypassed. Instead, some of the wire connections were going to a post on the ammeter (2 post style, not loop) while others directly to the key switch. Presumaby the ammeter post was being used as a terminal post. Again, all of that has been corrected, except I bypassed the ammeter to get it to run. When I connect the wire from the solenoid to one post on the ammeter, and a pigtail wire from the other side of the ammeter to the terminal block, I lose voltage. I measure ~6.2 volts on the incoming side and less than 3 volts on the outgoing side. And I get those same measurements at the coil. I'm sure you can probably guess what that means.

Is that simply telling me the ammeter is faulty? Why would I lose voltage through the ammeter?

I also have one wire I can't figure out what to do with. I have a blue voltage regulator with 3 terminal connections along the bottom. I traced out the field, battery, and arm wires. I'm left with the ground wire from generator to VR, but I don't see a ground terminal on my VR. Any ideas? Could this be causing my other problem? I tend to doubt it. I assume a lack of ground would mean a lack of voltage somewhere, not a drop in voltage.

Thanks in advance.

 

[JMOR]

Short across the ammeter terminals and see if that makes other things work. Just attach the ground wire to VR mounting screw.

 

[Jim.ME]

I have a 1950 8N, 6 volt system with a side mount distributor. The previous owner left it with the property we bought 10 years ago and it's been sitting ever since. I'm finally getting around to trying to make it run.

What I have done so far is to correct the wiring according to the many diagrams I have found posted in this forum, fixed or replaced broken splices, took apart and cleaned the carb, fixed a grounding issue in the distributor, replaced the coil and spark plug wires, thoroughly cleaned the spark plugs, verified the points are working, and a few other odds and ends. I still have the hood off, but I can now get it to turn over and run on ether.

When I began this odyssey, I discovered the terminal block on the back of the dash was completely bypassed. Instead, some of the wire connections were going to a post on the ammeter (2 post style, not loop) while others directly to the key switch. Presumaby the ammeter post was being used as a terminal post. Again, all of that has been corrected, except I bypassed the ammeter to get it to run. When I connect the wire from the solenoid to one post on the ammeter, and a pigtail wire from the other side of the ammeter to the terminal block, I lose voltage. I measure ~6.2 volts on the incoming side and less than 3 volts on the outgoing side. And I get those same measurements at the coil. I'm sure you can probably guess what that means.

Is that simply telling me the ammeter is faulty? Why would I lose voltage through the ammeter?

I also have one wire I can't figure out what to do with. I have a blue voltage regulator with 3 terminal connections along the bottom. I traced out the field, battery, and arm wires. I'm left with the ground wire from generator to VR, but I don't see a ground terminal on my VR. Any ideas? Could this be causing my other problem? I tend to doubt it. I assume a lack of ground would mean a lack of voltage somewhere, not a drop in voltage.

Thanks in advance.

Welcome to the forums.

Start by following JMOR's suggestion.

Just a point on what you said about the voltage regulator. The color means nothing! We went through this in a thread a while back when someone insisted a blue regulator was 12-volt because a catalog showed blue 12-volt regulators and the 6-volt were black. In the end he found out that blue regular was in fact 6-volt. My point is don't go by colors alone, manufacturers vary colors, a red battery cable can be on a negative terminal just as well as a positive. Colors in wiring harnesses aren't always as a book shows. Verify where wires go as you have. Some regulators had terminals on the underside of them, only visible when the regulator was not mounted.

 

[IndianaJones50]

Short across the ammeter terminals and see if that makes other things work. Just attach the ground wire to VR mounting screw.

I’ll try that. Thank you.

 

[IndianaJones50]

Welcome to the forums.

Start by following JMOR's suggestion.

Just a point on what you said about the voltage regulator. The color means nothing! We went through this in a thread a while back when someone insisted a blue regulator was 12-volt because a catalog showed blue 12-volt regulators and the 6-volt were black. In the end he found out that blue regular was in fact 6-volt. My point is don't go by colors alone, manufacturers vary colors, a red battery cable can be on a negative terminal just as well as a positive.

Good point on the color of the VR. I haven’t tackled the charging system yet but will keep all of that in mind when I get there.

Colors in wiring harnesses aren't always as a book shows. Verify where wires go as you have. Some regulators had terminals on the underside of them, only visible when the regulator was not mounted.

I learned that very early on. A number of wire colors didn’t match the diagrams. Taking nothing for granted, I disconnected and traced all wires using an ohmmeter. I’m fairly confident I have it correct now.

I do appreciate the advice.

 

[IndianaJones50]

Circling back around on this…. Shorting across the ammeter posts worked. I now measure 6+ volts at the coil and the tractor runs!

The ammeter doesn’t register anything. My next step I think is to test for a functional generator and/or voltage regulator, and probably replacing the ammeter.

Thanks so much for the warm welcome and great advice. This forum has been a great resource. Had I known the wealth of information available, and the number of folks willing to help, I wouldn’t have waited so long to attempt to resurrect this unit.

 

[olddavid]

To get my nephew's inherited TO-35 to work I had to take the ammeter out and short the wires together. It took a little while to find it since I had never seen one that wouldn't pass current through it. It had been sitting out for several years.

 

[JJay48]

This is why I am going to a voltmeter on my 12v conversion. I don't want the amp meter to be a failure point and I find a volt meter to be more useful.