voltage drops to only 24.6 or so.testing done with tires off ground so system is not under heavy stress.
pulled the 2 top brushes on left motor and they still have 7.5mm before reaching wear mark so they are worn about 5mm from new.will jack up and try to get to the bottom ones as well and order new springs just in case they are weak.springs check out ok but??
good thing i like this lift cause it's driving me NUTS.
may try another commutation capacitor if i can find something with similar specs.
[email address removed]

What are your battery voltage dropping to when you are trying to accelerate? I live in NE Alabama. Post your e-mail.

replaced all 4 microswitches on steering as 1 had fluctuating resistance.didn't cure anything. accel unit and ouput voltage checks out against manual going smoothly from 1.2 to 8.98 volts.checked contactor detecting circuit and get 26.1v on all 4 contacts.checked mps and seems i may have a problem there but not sure.if testing with motors not spinning(since the thing mostly won't run) voltage stays at 8.89v or so.got motors to spin a bit and voltage goes from 2.23 to 5volts depending on accel position(factory says 10v released and 1v wot). but then contactors drop out if volts go too high or too low so i try to hold accel pedal at same speed.sometimes it'll run and sometimes it drops after a few seconds.resetting f/r switch works but only if i throw it in opposite direction.switching from eco to power trips it but going from power to eco doesn't most of the time.there is no steady behavior.
there is a sweet spot on accel pedal where the motors will run but not all the time.
if pedal is barely pushed so only the microswitch clicks the motors will hum a bit longer before contactor drops out.the more gas the quicker the drop out.had it running on blocks for about 8mn and nothing seems to get overly hot so not sure what to do next!!
where are you in alabama?

If you have a service manual perform the accelerator unit inspection and performance check.

removed accel unit from pedal. microswitch was misadjusted and did not interupt contact.readjusted it and now clicks at first touch of pedal and hum is gone in forward or reverse.
hum starts when pedal is first touched but then contactors drop out within 1/4 second so still no go.
doesn't look like accel unit was ever tempered with as white paint on screws still intact on circuit board and microswitch.

will put it back on blocks weather allowing tomorrow and run all the tests following service book.

yeap.and when truck runs,the motors do as they are supposed to..reversing or slowing down depending on steering angle.
also tried it while driving and you can feel it as well.
it did drop out a few times when hitting the first step on the steer cam.resetting the f/r lever got it going again.as usual these drop outs happen occasionally assuming the truck even runs.
went out to try to get it to move again and still no luck but tomorrow is another day?

One more thing..........did you block the lift up and check the rotation of of drive motors as i posted earlier?

sure did and they all check out good going from o to infinite upon closing and opening but will check them again along with accel unit( thought i heard the microswitch in it once but not too sure)

Did you ohm the switches out on the cam? To make sure they are closing and releasing?

yes,the steering pump is still not connected at the relay so it doesn't drain power while i'm testing things and makes it easier to track other noises.
the thing is that, it always hums whether it runs correctly or not so had no way of knowing if it was correct behavior seeing it's my first foray into the electric forklift world.
i'll test the accel unit for proper operation now that i have a service manual and report back.you mentioned a trick to adjusting this a while back?
you are correct in that checking main drive motors is a pain.had to remove the tilt cylinder and steering pump assembly to get to motor shrouds
did check the 4 steering cam microswitches a while back and all operated normally(closing and opening as cam pushes or releases them).
stay tuned.

It should not be humming when just simply selecting f or r. I would check my accel pedal adjustment external stops. This unit has an electric motor for steering so this rules out pump hum. The hum you hear is probably the scr that is cutting on when you are selecting travel direction and should not be heard unless you are depressing the accel pedal. Try and adjust the release stop for the accel pedal to get the scr hum out. The steer cam has several micro switches and these should be checked for proper operation.

finally an update.checked brushes for arcing and general shape.lenght is within tolerance with minor variations on different brushes(+/_ 1mm) and no arcing when running.powering truck with a decent battery now.voltage doesn't drop to below 24v when under drive load.
sometimes and as before when turning sharply left or right(when steering switches are activated by steering cam) the drive motors will drop out.resetting the f/r switch will get things going again.drove it 3 blocks and all was good then parked it.the next day contactors drop out again at slightest touch of pedal.25.7v on battery so not a charge issue.will be looking at contactor detecting unit for proper voltage tomorrow.
is this truck supposed to hum(fairly loudly) when f/r switch is engaged and the pedal is not depressed?
if only i could find a SCC-02C EVS analyzer:(

And i hope this is a 3 wheeler LOL

One other thought you might want to try and this involves jacking unit up and blocking unit to get drive tires off ground. Remove floor board and check if your motor brushes for drive tires ( 2 ) are good and not arching. they are a pain as the motors are stack one on top of other.Sometimes they will not make commutator contact and drop contactors out. Batteries are a problem also as you are not getting but only 5 minutes run time and will travel no faster than walking speed. Best to also get steer tire off ground and run lift while turning left and right. When turning right while sitting on lift, the right drive tire should slow down and at almost lock, it should turn backwards. Same is true when turning left.....left should slow and at lock turn backwards. As i said check yer brushes and let me know what you find out.