Trouble Shooting: '94 Medalist Speed Controller

[Big Stace 99]

Originally Posted by JohnnieB

Without an elaborate test bench, about the only way to find out if a controller is good or bad, is eliminate the other possibilities.

You've got new batteries, new 4Ga cables, the solenoid clicks and you get battery voltage between M- and B- when solenoid first clicks, but voltage doesn't decrease to near zero when pedal is pushed to floor.
That pretty much narrows it down to a bad controller or a bad throttle (ITS)

Connect your DVM's negative test lead to the battery pack's main negative terminal.
Check for B+ (battery pack voltage) at Pin-4 (Red wire) when pedal is pushed.
Pin-3 only has voltage on it when F/R is in R (It puts controller in 1/2 speed reverse mode)

The throttle input is pins 1 & 2
After solenoid clicks, the voltage on Pin-2 (Black wire) should be from 9.0V to 11.5V
When the solenoid first clicks, Pin-1 (white wire) should be 0.4V to 0.6V and when pedal is pushed to floor, it should be 1.5V to 1.7V.

If the controller is turned on (B+ on Pin-4) and the ITS voltages are correct, the controller is bad.

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Since you are running 22" tires, you will need a 400A or greater controller. (Stock controller is 275A, so a new stock controller will soon fail trying to turn the oversize tires)
Check out the Controller/Solenoid kits sold here:
http://www.cartsunlimited.net/Custom_Options.html

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Everything is exactly as you said & in range with one exception: I'm out of range on the black wire which has 14.6V. Probably more evidence of a smoked controller.?.?
White wire is .475~.610V when pedal is pushed to floor & orange wire has voltage in reverse mode. Looks like I'll be calling ScottyB for a new controller.

Thanks again for EXCELLENT troubleshooting info!

[scottyb]

Stock Controller is 350 amps in that cart. A good economical aftermarket 400a replacement would be our pkg # 101. A nice 500a upgrade unit would pkg # 202. Both of these packages include heavy duty solenoid.