36.9 volts is this just sitting still. That is on the low side a fully charged battery pack 36 volts should be more like 37 -38 volts. While you are riding the cart see what the voltage is. If it drops as you stated before below 36 and doesn't come back up once you get moving then the batteries are gone.
When you hit wide open the coils should cool off because they are bypassed in the circuit then!
thanks solenoids four and five are bad when I jumped them the speed pick up still a little slow but a brush kit may help . battery are fully charged and up to 38 and come back to 37.8 when running. thanks a lot