Ammeter in 337G

[AV8ing]

Since this is my 1st post, a quick intro is in order: I'm an American ex-pat living in Europe for over 25 years. I am a fanatical pilot/owner/FAA A&P mechanic. Currently own a 1947 Cessna 140, a Cardinal RG and a Turbo Centurion. Recently, I have started to look after after a couple of 337s ...

I was hoping I might be able to get some help with a couple of issues on a '74 337G :

Ammeter - There's a small 1" ammeter over on the right side of the panel. I believe it was optional and is listed as p/n CM2626-N1 on the MM Wiring Diagram. The issue is that it appears to be inop - does not show any or very little indication. It tested ok with a multimeter and I traced the wires back to 2 fuses & shunt on the firewall, all seems ok.

Is this ammeter just useless or ?


Gear warning horn adjustment - The gear warning switches need to be re-adjusted. The problem, when ground testing for adjustment, no matter what the settings are with the switches, the gear horn always sounds when the green gear light is pressed. I went so far as to completely disconnect both gear switches and no change the gear horn sounds when the green gear light is pressed. I maintain about 10 SEP Cessna retractables and have never
seen this.
Any ideas why I can't simulate gear up with green gear
light ?

Thanks a 1,000,000 !