How do you test a motor when you got it out of cart 36 volt

have load test done on battery's --load test on motor --regulator tested

You need a volt meter the problem is some ware between the battery and the ignition switch .Check battery grounds all if bat is grounded you should have 6.5 v D.C from B+ to anything on the engine or frame one at a time then test both for 13 v at the same time jump them together .This could be your problem 2 battery's with 1 bad ground .Then start from the other end the ignition switch use jumper leads hook to the switch in start position key turned to black to ground see what you have for voltage drop it should be around 12 volts if you have nothing its the ignition switch if you have less then 12 v its likely a bad ground from one of the battery's or something related to the drive motor

if the wires have been cut but they are still in the harness the the colour of each wire can be paired back up to start with
the rest if any left will be touch and feel what happens

never mix different voltages VERY BAD

batteries will get hot when working as there is current flow across the plates . For batteries to get noticeable hot then there is a current draw that exceeds the capacity of the battery . This indicates a problem electric motor in the system (Worn bushes/bearings -armature poling out --shorting windings or armature) it may also indicate shorting between batteries from a battery that has collapsing cells . Have each battery inderpendently load tested

GOES LIKE THIS..

CART MOTOR, Positive, Negative, Postive, Negative. Ect... Back to the other side of the Motor

Its been a wile but if I remember right it goes from the solenoid under the cart (pass side) to the key switch (the other wire is probably volt meter) then micro switch,green wires from micro switch to controllern. Inspect all spade connections

Your Relay may be out

Your batteries have died. The reason it will barely move in reverse is that current is being supplied to the motor is a direction that it spends very little time using. There is a slight change in the armature over time, and reverse tends to work better over time. Check the voltage when under load. (run jumper wires from the + and - of the battery bank. If it is a 36 volt cart and the voltage drops to below 36 volts, you do not have enoug current to run the cart. Plug in the charger and watch the ampmeter. If it goes up to about 20 amps, then it is charging. It should take a good charge after 10 hours. If the cart charges and only runs a short distance, the batteries need replacing.

replace the voltage controller for the drive motor.