Ammeter for '38 1/2 ton Pickup

[johnseabee]

Hi all,

 

      I am looking for a more clear wiring diagram or schematic for the Ammeter connections in the instrument  cluster of my '38 Dodge pickup. This Ammeter in my  3 contact posts. One should be battery in, one should be battery out I think but, there is one more that I am not sure of. The Ammeter has a fixed fuse holder that breakes the connection from 1 to the 3rd post. My guess is that would be the post that goes to the rest of the electrical but, again not sure.

           Any assistance would be greatly appreciated. Thank you, John

[Young Ed]

I believe in these older cars/trucks that extra post is like the accessory terminal although probably not switched.

[johnseabee]

I followed the one wire that went to that post and it led to the battery terminal on the Voltage regulator???

[David Strieb]

The ammeter on my '38 RC has 2 posts on the back. Doesn't seem right that your third post would be wired to the voltage regulator, seems like it would be an accessory power outlet as mentioned before.  I'll look to see if I have a wiring schematic.

[David Strieb]

The ammeter on my '38 RC has 2 posts on the back. Doesn't seem right that your third post would be wired to the voltage regulator, seems like it would be an accessory power outlet as mentioned before.  I'll look to see if I have a wiring schematic.

 

 I was wrong, my '38 RC ammeter also has 3 posts. I used the fused post to run power to a fuse block from which I run headlights/taillights, dash lights, wipers, heater, and radio from. Also changed over to 12 volt.

 

   My shop manual indicates that  one unfused post is connected to the power stud on the starter, the other unfused pole is connected to the generator and relay, and the fused post powers the headlight/taillight switch, the horn, and the instrument panel light switch. The manual doesn't indicate what gauge wire was used on any of those circuits.

[T120]

I found this wiring diagram on line,not sure if you've seen it. You can zoom in on the diagram. It shows the connections to your ammeter (U).

     

Edited October 29, 2014 by Ralph D25cpe

[deathbound]

 I was wrong, my '38 RC ammeter also has 3 posts. I used the fused post to run power to a fuse block from which I run headlights/taillights, dash lights, wipers, heater, and radio from. Also changed over to 12 volt.

 

   My shop manual indicates that  one unfused post is connected to the power stud on the starter, the other unfused pole is connected to the generator and relay, and the fused post powers the headlight/taillight switch, the horn, and the instrument panel light switch. The manual doesn't indicate what gauge wire was used on any of those circuits.

 

If you have the original wiring that isn't too faded (or can be exposed under the cloth loom), here is a chart to determine which wire gauge was used.........http://oldmopar.com/oldmopar/wirecodes.html