Gem main contactor

GEM Golf Cart Year Model 2000:

Main Contactor cliks sometimes and does not click other times. If you touch it, it is hot (sometimes very hot). Electric motor does not run. Low voltage accesories (12 V circuit) work fine, but not the High Voltage circuit (72 V).
Is it the Main Contactor or could also be the accelerator potentiometer??

Does anybody can help, please.

Thanks.

SCOPE OF SUPPLY
The Steam Generator will be supplied with the following:
· One helical wound vertical coil made out of ERW pipes.
· One jacketed design to enclose the vertical coil to minimize losses.
· One pressure jet down firing burner assembly.
· One blower coupled with motor.
· One fuel pumps with motor.
· One boiler feed pump mounted on base frame.
· One specially designs atmospheric economizer and heat optimizer for preheating the feed water.
· One feed water line between economizer, feed water pump and boiler.
· One fuel oil line from oil filter to burner inlet.
· One dust proof control panel housing necessary MCB, contactor, relays, etc.

Mountings and fittings
· One main steam stop valve.
· One steam bypass valve.
· One spring loaded safety valve.
· One blow down valve.
· One non-return valve.
· One anti drip burner assembly. ( BURNER FROM ITALY)

Instrumentation
· One steam pressure gauge.
· One steam pressure switch.
· One digital steam temperature indicator cum controller.
· One flame failure device consisting of sequence controller and photocell.
· One hooter for abnormal conditions.
· One limit switch on blow down line.