1940 ammeter wiring question.

F

FROG_PONDS

Member
I am restoring a 40 ford pickup that I got all apart. Let me start at the ''wiring'' beginning. Looking at the rear of the gauge cluster I see four gauges. The two on the left and the two gauges on the right have a brass bar between the two outside posts on both sets of gauges. I decided to install a''Rebel Wire''wiring harness with 8 circuits. The wiring diagram indicated a 10 gauge wire be run from the battery side of the solenoid thru a fuseable link to one post on the ammeter and from the other post on the ammeter to a junction box. Now it indicated to run a 10 gauge wire from the junction box over to the ''B'' post on the regulator. It also indicated to run a 10 gauge wire from the junction box to the fuse box. Before I ran the wires I removed the brass bar from the one post on the ammeter. Now my first startup I burnt up the fuseable link. After looking for a long time I found my dead short. I found out the ammeter was infact grounded at the post that had the brass bar. I then added a fiber washer to the post that was grounded, reconnected the wire and now I have no power to the fuse box. My questionis can I run both wires to one side of the ammeter and ground the other post? Rich
 
40 pick up should have ammeter with a loop on the back side thru which a 10 gauge wire runs thru, this gauge only tells if it is charging (engine running) or not
 
Looking at the parts book 1940 used a battery charge indicator (volt meter) Part
01A-10844-B. That would be why there is the brass connector between the two gauges.

Bob
 

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The wiring diagrams show both the std and deluxe have a volt meter (call a battery indicator). Not sure on the pickup, but should be similar to the standard. An amp meter would not be connected using the brass strip, no way it would work that way.
 
FROG_PONDS said:
I do not understand at all what you mean. Rich
Click to expand...
Most early Ford Amp Meters did not have connectors on them, just a metal loop that the wire from the battery passed through. There was no physical connection, the meter just senses the magnetic field around the wire.
 
OK --As I look at the gauge face I see the word ''BATT''. If it is a volt meter can I put a 6volt wire on one terminal and ground the other terminal? Rich
 
Yes the bars were there as you discribed. I removed one because of the bad info given me from a very generic wiring diagram from ''REBEL WIRE''. and ended up with a short. I still think I can run a hot wire to one side and ground the other. Rich
 
FROG_PONDS said:
OK --As I look at the gauge face I see the word ''BATT''. If it is a volt meter can I put a 6volt wire on one terminal and ground the other terminal? Rich
Click to expand...

The Bar is the hot side, the other side is grounded. Have you looked at the wiring diagram for the 40 std? It shows it is grounded. You are going to have a hard time with the wiring without using the wiring diagram! Are you maintaining the Positive ground?
 
Yes I am using several old ford wiring diagrams along with the REBEL diagram. So far I have everything working except for this gauge. My problem was not knowing that this was a voltmeter and the very vague information from BEBEL WIRE. Rich
 
I'm surprised REBEL provided any information related to flatheads! The gauge may have been damaged with the previous wiring setup or may not have worked in the first place. try running some dedicated wires directly to it. In you earlier post you believed that the Bar was the ground side of the gauge, don't think that is correct. All of the gauges are connected together on the power side and then the grounds provided through the other terminal. The Temp, Fuel & Oil Press are grounded thought their sender units, the volt meter is grounded directly. So, based on your earlier post sounds like you have it connected backward.
 

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Thanks for all the help--Based on the information you ford lovers have given me I am going to connect it up as a voltmeter. The diagram given me from REBEL WIRE indicated an ammeter and I wired it up that way. They were very helpful when I called them but never said it could be a voltmeter. Thanks Rich
 
Hi Rich, on the back of the ford battery voltmeter gauge there are two terminals, one of which has a piece of grey fibre insulating material under the inside terminal nut, so that is the terminal that is powered by the ignition switch via the brass strip. The other terminal has only one nut on it which screws down hard on the gauge casing which gives it a ground connection. Easy to tell an ammeter from a BAT or voltmeter gauge. The voltmeter needle is at rest at the bottom of the dial (with ign off) whereas an ammeter will have the needle at rest in the centre of the dial. Regards, Kevin.
 
The Ford voltmeter is 6V if you have changed to 12V you will have to put a voltage drop in the voltmeter circuit.
 
40 pickup should be an ammeter, gauge cluster looks just like the "standard" car but has an ammeter instead of a battery volt indicator. Atleast that's what my 40 pickup cluster looks like.
Martin.
 
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