1939 to 47 Ammeter wiring question

[PT81PlymouthPickup]

I have wired my 1939 PT81's amp meter as per Mopar wiring diagram. The light switch and the horn are wired to the third terminal on the ammeter which is fused. Everything is working fine, but neither the lights or the horn show any indication of draw on the amp gauge when I use them. Does this sound correct? I know the ammeter is working properly because other accessories such as heater motor indicate a draw. I'm guessing that Mopar originally used the ammeter for just the charging circuit?

[lostviking]

Mine shows a draw when I turn on the lights, 1946.

[PT81PlymouthPickup]

11 hours ago, lostviking said:

Mine shows a draw when I turn on the lights, 1946.

Does your ammeter have a fuse in the back of it?

[lostviking]

Sorry for the delay. No, there isn't supposed to be one either. I goes from the regulator through the ameter to everything else...via the light switch. Lights do not go through the ign switch, so you should see draw with just the lights on. The current comes from Batt (-) through the ameter to the light switch (makes a stop at the starter first), N0 10 Red wire, then No 12 Brown wire to the light switch.

[PT81PlymouthPickup]

On 7/24/2022 at 3:53 PM, lostviking said:

Sorry for the delay. No, there isn't supposed to be one either. I goes from the regulator through the ameter to everything else...via the light switch. Lights do not go through the ign switch, so you should see draw with just the lights on. The current comes from Batt (-) through the ameter to the light switch (makes a stop at the starter first), N0 10 Red wire, then No 12 Brown wire to the light switch.

My 1939 has a fused third terminal on the ammeter which was hooked up only to the light switch and horn. The fused terminal does not go through the gauge. On my truck as originally wired, the only thing registering on the meter was the charging circuit. I'm confused why they did it that way? Turning on lights or using horn does not show any draw.  Not certain, but I think 39 might have been the last year for that? I believe in 1940 the light switch was wired from the ammeter and there was a fuse on the light switch.