Buggies Gone Wild Golf Cart Forum - View Single Post

JohnnieB · 03-03-2013, 02:12 PM

That 0.1V to 3V lower is for a 36V system with a 250 Ohm precharge resistor and a 48V system should have a 400 Ohm resistor, so the voltage drop won't be the same.
Anyway, the resistor isn't the problem, since the cart will run with or without it.

I'm speculating, but I suspect the high pitched noise is the Pulse Width Modulated (PWM) DC arcing across the F/R switch contacts or a broken cable.
The PWM frequency is in the high audio range (15-18 kHz)

Jack the rear end of the cart up so it doesn't run over anybody.
Connect your voltmeter test leads between the B- and M- terminals on the controller.
You should read FULL battery pack voltage when the solenoid first clicks.
If not, trace the high current cables back until you find it.

03-03-2013, 02:12 PM	#3
JohnnieB Techno-Nerd Join Date: Jun 2011 Location: West Virginia Posts: 19,654	Re: FnR switch high pitch noise That 0.1V to 3V lower is for a 36V system with a 250 Ohm precharge resistor and a 48V system should have a 400 Ohm resistor, so the voltage drop won't be the same. Anyway, the resistor isn't the problem, since the cart will run with or without it. I'm speculating, but I suspect the high pitched noise is the Pulse Width Modulated (PWM) DC arcing across the F/R switch contacts or a broken cable. The PWM frequency is in the high audio range (15-18 kHz) Jack the rear end of the cart up so it doesn't run over anybody. Connect your voltmeter test leads between the B- and M- terminals on the controller. You should read FULL battery pack voltage when the solenoid first clicks. If not, trace the high current cables back until you find it.