In Reply to: Re: ammeter posted by chris eby on April 30, 2018 at 11:03:50:
The original 9N Ammeters had chrome bezels (oil gauge too). They did change to black painted over brass housing later on, but not sure where the cutoff was. MPC's show the 9N-10850-B unit being used up thru 1952. Now, there are some other subtle differences. I have some ammeters with the word 'AMP' on the lower bottom face plate and the needle protrudes from a half moon window about 1/3rd the way up. I have had and seen some ammeters mostly on later 8N models, with the word "AMMETER" and the needle protrudes from a smaller hole nearer the bottom. Again. I can't tell you when or why, but I would think it is just likely a different supplier. I have never seen nor heard of any aftermarket company producing a LOOP style ammeter. Someone once posted of a 30 amp gauge that had a chrome bezel yet the four screw posts like the 20 amp style. I think it was suggested that it wasn't made for the 9N tractor. I had a picture and you could see the mfg TM, Stewart-Warner, etched on the back. So, I have to think it could have been a transitional piece.