Ground = 36v in reverse?

[tmclaren]

I have a 1983 EZ GO with the old resistor bank/mechanical accelerator switch. Attached is the wire diagram I followed to wire the cart.

I'm trying to install a radio so I'm using a step-down transformer (36 > 12v) to power the 12v system.

The step-down unit is a " Pro Chaser DC-DC 36V 48V Volt to 12V Step Down Golf Cart Voltage Reducer Regulator 10A 10 Amp 120W" from Amazon: https://www.amazon.com/Pro-Chaser-Vo...tronics&sr=1-1

It's a 3 wire system so per instructions I installed + (red) on the first battery positive terminal and - (black) on the last (6th) battery negative terminal. I then ran the output 12v (yellow) to a fuse block and complete that circuit with a ground from the 6th battery terminal.

Using a volt meter I get 12v on the radio plug when the cart is in fwd/neutral but when I move the switch to reverse I get the full 36v and that appears to becoming from ground.

If this reverse polarity is by design then I guess I'll have to isolate the 12v ground from the 36v system. Has anyone run into this before? Any thought about cause/correction?

Thank you,

Terry McLaren

[Mooncarter]

I'm not sure why you are getting 36v when in reverse. I'm sure others can chime in and explain that.

I would get rid of that reducer, and at a bare minimum get one that has 12v pos. & neg. outputs.