good deal
glad it worked out

after going through that circuit the only thing that made sense to me was an internal fault inside that PMTD, maybe a bad diode or a switching transistor.

I did think that there might of been something with the reverse coil or that circuit or wiring but since your voltages were all mostly on the mark i started leaning toward that driver ;o)

As for that 10v signal you were questioning, was probably some feedback from the HMD (hour meter driver).

Swoop223, you got it, it was the PMTD driver.
After replacing it, forklift is working fine Forward and Reverse!
Thanks to both of you, Bernard

Thanks again guys for your help. After checking most of the wires for continuity and short to chassis which turned out negative, I started to check voltages across L terminals. With Key ON & Seat ON, I got battery voltage (around 50V) on L3, L5 & L7. With Monotrol at beginning of FW position, I measured 50V on L9 and zero volts on L10. With Monotrol at beginning of Reverse position, I get full 50V on L10 but also partial (about 10V) on terminal L9! Could the FW/R DPST switch somehow "leak" the voltage from contact to contact? Would it be safe for the EV-1 controller to disconnect wire 6 (FW control from L9) and try the reverse motion?

A Hyster with a Monotrol is is wired different than the schematic in the GE manual because it uses just the one directional switch that has one circuit NC and one NO. That's what the 7-1 wires on L5 are doing. L5 is the circuit that turns on the card. A Hyster schematic would sure help. I would check to see if you are loosing + battery voltage at L5 when it acts up.

hi Rhopac
well there is the PMTD
that is the only other component that is associated with all the other components in the circuit.
being that the truck is pulsating or surging when accelerated at the point or after the 1A switch is made tells me either the reverse circuit has an issue in the main fwd/rev contactors or the PMTD.

Since you replaced the 1A driver that rules that out, but actually if it goes into 1A in forward that ruled that out already.

i would pay attention to the PMTD and the fwd/rev contactors and coils.
If you want some basic EV1 troubleshooting help you can go to:
h t t p://w w w.fsip.biz/Documents/EV1.pdf
^^^ remove the spaces i added so this url would post ^^^

There are troubleshooting charts and diagrams that should help alot. Check tables 1H symptoms and Table 3, they cover these type issues with 1A problems.

Yes, as long as you don't activate 1A switch, you can move the forklift in reverse and as long as you are smooth on the pedal, it smoothly speeds up in reverse to the point of activating the 1A switch then it start pulsating like on/off but reverse contactor stays ON at all time, no sparks. I'm not sure if I have correct schematic for E30BS but I can't trace the wire #15 (common for both contacts of directional switch) to EV-1. My Diagram is showing L5 to #15 connection but in reality, L5 terminal has two 7-1 wires on it, non of which has any relation to #15 at the switch when checked with an ohm meter. When I put the meter across #15 and #8 of the switch and press FW (NC contact, meter needle drops but not all the way to infinity resistance). Switch checks out fine.
You are also correct on 1AD, just replaced it with new one and same thing is happening.
Thanks again, mrfixit.

Describe a little better how the machine reacts as you go in reverse. Does it operate correctly as long as the 1A switch is not activated? Once you floor it and activate the 1A switch what happens? When it is jerking, is the reverse contactor chattering on and off? Is the 1A contactor doing anything? The PMTD, HMD, and 1AD are all working OK in forward so it rules them out.

I checked the EV-1 settings and they are pretty much as listed, C/L was at 7 and 1A time was at 6.
Mr. Fix it, thanks for pointing me to the Monotrol switch. I found wires rubbing against the hydraulic tank as the pedal moves and insulation scraped off from wire 15 (L5) common of the directional switch, which I fixed. Paint of the tank was rubbed off also in that spot so there could of been short to chassis on L5.
Schematic shows both contacts of this switch NO but I believe the reverse contact is NC. After pushing the pedal to FW direction, this contact between wire 15 & 8 drops but I can see 200K residual resistance on my analog and digital meter.
I will remove the switch to check without wires connected.
This is probably the resistance swoop223 is talking about.
Could PMTD, HMD or 1AD be the problem or is it in the EV-1 board between L5 and L10? I will disconnect these wires and check continuity.
How can I upload or attach electrical diagram/schematic to this reply?
Thanks to both of you for your help. Bernard

check the potentiometer voltage when pressing the pedal in reverse.

the 1A contactor does not activate until the voltage reaches 0.5v.
make sure it achieves this voltage in both forward and reverse.

you may have some resistance in the reverse control circuit that is keeping it from achieving it's required voltage to allow 1A to pull in.

a simple adjustment to the C/A setting may help this out, it should be set to 9, if not then adjust it to 9.

the rapid tune up settings are as follows
creep: 7
C/A: 9
C/L: 6 (this is set at factory and should not need adj)
1A time: 7
1A DO: 3
Plug: 5
FWPU: --
FWDO: --

Sounds like the Monotrol petal has a problem. Did you check the switch on it and make sure it is adjusted properly? Also check the wiring to the Monotrol that has to move as the petal is pressed. I don't think there is a problem with the EV1 if forward is working ok.