Yamaha G16E Runs Fine In Reverse Nothing But a Whine/Hiss in Forward

[Bluemonster]

I purchased a cheap Yamaha G16E golf cart as a project. The golf cart runs fine in reverse but in forward there is only a hushed whine/ hiss almost like a static sound from the motor.
New solenoid, professionally rebuilt controller, brand NEW batteries, new cables and all electronic systems appear to be in place and operational.
Assume obviously a motor problem (in forward only) but new to these large motors.
Any suggestions on further diagnosis or feedback on troubleshooting would be appreciated.
P.S. searched forums til my eyes bled could not find similar posts
Thanks...

 

[HotRodCarts]

If the motor runs in reverse is should be good. What does the battery pack voltage drop to in forward when the golf car is making the whine/hissing noise?
Welcome to the forum.

 

[Bluemonster]

Thanks for the reply. Static voltage is 38v. In forward drive with the wheels off the ground it only drops to 361/2 to 37v. Using analog meter as my digital one does not seem to register.
Cart drives and pulls strongly in reverse even uphill but will not even rotate wheels in forward when jacked off the ground.
I understand the importance of voltage, good charge and tight connections. All motor posts and terminals were cleaned, polished and reconnected.
Wondering if this could have something to do with motor windings or brushes??
Running another charge cycle to be sure...

 

[Bluemonster]

After more research found YouTube tutorial and tested motor by jumping A2 to S1 and direct powering. Motor ran fine in forward with direct power.
Now I surmise a problem with F/R switch as other components are new or rebuilt.
Any tips on this process would be appreciated.
Thanks

 

[Zman]

Sounds like F&R problem