I think all service techs will agree that it is extremely more difficult to diagnose problems by reading something on the internet rather than if they were standing next to the forklift and looking and listening to it. Sometimes it takes a while.

Yup...I missed that too
You did say the brushes were new
I shouldn't have assumed that you had seated the brushes, because i did.
I always clean the commentator when replacing brushes and use a seating stone.
What happens when you don't seat them there is a high possibility that a brush could jump off the surface breaking contact causing a drive error.
If you've ever heard clicking sound during run time that would be because the com bars have raised, generally caused from stalling the motor.
Anyways...

DOH!

Good deal though, glad you asked that mrfixit

I am Feeling stupid at this point found the problem the first one was me. I kept looking at the Commutator and saying i should clean that and was stuck in the issue of it doing what it was doing and finally on a whim or wits end cleaned the com and it works like a million bucks. So thank you mr fixit for all your help and i need to Keep It Simple Stupid

That's a very odd problem you got. The things I would check is to make sure the pot and wiring are good. Does the forward and reverse contactors have interlock switches mounted on the bottom of them? One of the circuits in those switches is used to turn on the SCR controls, so check that. Does it have an optional fault detection card? But I think that would shut the contactor off if it detected a problem. Did you seat the new brushes to the commutator? I'll look at the schematic for that truck and see if there are any other ideas.

MrFixit If I put it under load with the brake it doesnt kick out. It will continue to run in both directions.

The 1A comes in when it is suppose to with the actuation of the throttle i have been looking at the manual on this system. Just figured i couldnt be the only one who has ran into this situation. Was hoping i just was overlooking something. MRfixit i will try that in the am and let you guys know what happens. I checked the 37 wire and its fine

if the 1A operates manually then i would check the accelerator , it has a switch in it that should make when the pedal is near 100% which calls for pulling in the 1A contactor.
open up the accelerator box and check that switch and all of its wiring, even the connection at the plug on the box.

one other consideration to make is the 1A time setting on card1.

if you want a manual that will help you with this try checking fsip.biz , they have one in the technical section under GE Technical Manuals.

Hmmm, try bypassing the brake switch, hold the brake on, and drive it. Does it act different while the drive motor is under a hard load?

I will Look at that the forward contactor doesnt open until you release the switch

When you loose drive, and then when you go into 1A and it picks up to full speed, then ease back out of 1A and it stops running again, does the forward contactor stay in and not shut off until you release throttle all the way. In other words, is the forward contactor ever dropping out on it's own. I seems like it might be loosing the turn on signal from the card to #1 rec. Maybe try to run a new wire from card #37 to rec 1 gate.

Ok i did start checking connections contact tips are new the brushes are new. I did turn the top scr speed down and it seems to help it it only cuts out right before 1a engages but then once you release 1a the drive is gone until you return the accelerator to off. then you can go back into forward or reverse. and the truck is off the ground while this is happening havent tried driving it on the ground yet

Ok so it cuts out at random voltages. " stops oscillating " try removing the diodes. I think bad connection. If the diode is stuck then that would be where I would go. Besides the common bad brushes ,contactors and battery. Does it work ok off the ground. It's tough with out listening to it.

OK no field weakening contactor

Pot voltage is 5.79 at creep and drops to.2 at wide open tried 3 different pots. also tried a different card same outcome. What is drives me crazy is that it doesnt cut out at a certain voltage from the pot. Its almost like there is a RPM limiter in the scr once the motor reaches that rpm it cuts out but if you go into 1a it lets it accelerate past it. Talked to flight systems on this issue previously and they said i could pull the scr and send it in....

Does this have a feild weakening contactor

Is the accelerator voltage good. Should start at 3.4v ish and move down to 0.4 ish for full throttle. If it cutts out at 2. Volts the controller is faulty or set wrong.