VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt '37 Master Deluxe - Amp Meter

When I got my car, there was no wiring in it. It did have a new wiring harness, but the instructions that came with it were less than clear. I now have it installed, but am unsure I have all connections correct.

My question: When the engine is running and I turn on the lights the amp meter shows a charge. When the engine is off and I turn on the lights there is no indication of a discharge. Is this correct?

Thanks,

Rich

When the engine is running and the lights are on it should show a slight discharge at idle and when the engine is speeded up should go to charge. With the ignition off the ammeter should go to discharge when the lights are turned on.
I would suspect the problem is not with the ammeter but rather the wire feeding the light switch is hooked to the wrong location.
If the wire hook up is the same as a 1939 it appears that the feed wire is connected to the wrong side of the ignition switch.

Gene,

I have been studing the schematic and the way I see it, if the engine is running, power goes from the generator directly to one side of the amp meter. From that same leg of the amp meter, a wire goes through a fuze then to the light switch. Therefore, power supplied to the lights from the generator will not register on the amp meter.

If the engine is not running, power goes from the battery through the lug on the starter to the amp meter, through the amp meter to the lug that supplies power to the lights. This should show a discharge when the lights are on.

I am showing a charge when the engine is running and the lights are on and nothing when the lights are on and the engine is not running.

I would agree that the amp meter is working, but I have a wiring screw up. Part of the wiring has to be correct. After the engine starts, the amp meter pegs on charge then after a short while, the meter returns to the netural position, indicating that the power used to start the engine has been stored back in the battery.

Any flaws in my analysis? If not, then all I have to do is figure out what I did wrong when connecting the new wiring harness.

Rich

Gene is correct.......when the engine is running and the lights are on you should have a reading on the amp meter. You should also show a discharge on the amp meter with the engine off and the lights on.

:) :grin:

My last nights description for the wiring was incorrect. First the main wire should go from the battery terminal connection on the starter to the ammeter. Seeing that you have installed a voltage regulator The wire on the other side of the ammeter will then go to the Bat. terminal on the volt. reg and also to the batt. terminal on the light switch. No wire will go to the generator.

Gene,

I have cheated since we last spoke of the voltage regulator. I could never get the regulator to work even though I did confirm that the generator was producing current.

I now have an internally regulated single wire 6 volt alternator. I have it hooked up just like the original generator with the exception of the field wire which is not required.

Electrically, everything on the car works, but I believe that I am not charging the battery when the lights are on even though the amp meter says that I am. My only clue for this is that the battery went dead on the only night drive that I took. I drove about 25 minutes with the lights on and then did not have enough power to crank the engine. The battery was very likely not at a high level of charge at the start of this drive. However the alternator is supposed to produce 63 amps, way more than enough and triple what the generator will produce. When charging, the amp meter needle pegs. Max range is shown to be 20 amps on the meter.

I will crawl under the dash this weekend and review what I have done against the schematic.

Rich

Is it possible you killed the accuracy of your ammeter when you blasted it with 63Amps?

I suppose it is possible that I have damaged the amp meter, I had not even thought of that when I installed the alternator. However, it will still show both a charge and a discharge. I have a spare amp meter that I connected directly to the alternator a while back just to make a comparrison with the dash mounted unit. They read the same. I think I will disconnect the charging wire that goes to the starter positive lug and put the spare amp meter in there just to see if it shows the discharge when the lights are on and the engine is off. The only thing that is wierd is that it does not show a discharge in the engine off lights on condition. I did spend some time under the dash yesterday and as far as I can tell, the wiring is correct.

Rich

The engine off lights on condition where the amp meter does not show discharge suggests that the light switch is wired to the same side of the amp meter as the positive wire from the battery. If you move the wire to the headlight switch to the negative side of the amp meter then the you should show a discharge with lights on and engine off.

Chipper,

How right you are. I swapped that wire and all seems to be working correctly.

Thanks,

Rich