I saw this a few minutes after he posted it. Just luck. Boy, I had to think really hard. I would have 3 coupes, 36, 38, and 40. But I would be single again.
Make sure the cutout voltage is adjusted correctly. Use the procedures in the 1940 Shop Manual to check out VR settings. It doesn't take long to do.
Cheers, Dave
This is the one I use. 300 amp. I mount them on the inner fender wall and use #00 cable. Only adds about 2 feet of cable, but my batteries are under hood.
Menards
https://www.menards.com/main/electrical/light-switches-dimmers-outlets/light-switches/gardner-bender-reg-battery-shutoff-switch/gsw-bt/p-1642874300255863-c-6324.htm?exp=false
You see these for sale NOS on ebay from time to time. I got a nice Niehoff one a few years ago. I will try to find the stock number.
How is the coil failing? Just no workee?
Cheers Dave
Longer hood on the 70 series. The flat area on the front fender between the front door edge and where the fender starts to flare out is a few inches wider on the 70 series.