Hi, Did you finally fix your cat F30? Mine does the same--moves very slow and does not pull in the high speed contact. Battery is new. Thank you for any info.

would you know what the reason is for a code A ,is on a cat f30 machine I have no info on this machine my truck moves very slow and does not pull in the high speed contact.

made a mistake. i told you to check pin P2-6 this is not, the correct is P2-15.(B- to line coil)
and Sorry about my english...

assumming that all the wires are connected at their right place. i still think the card is not doing its job, since it is cutting the volt. to contactor coil (B-) and not displaying a failure code.
the card is working even if line contactor is out, for me is a normal "behavior "cause card and input devices are on by key sw.(key sw. is connected before contacts of cont.line). dO you have the wiring diag.?
if not, a can try to scan it for you. So you make sure about wiring

Blown out the motors with air hose. The resistance from frame to motor leads 1.2 megaohm. Also 1.2 megaohm from heat sink to frame. Battery voltage at rest is 38.4 volts. I have the lift on trailer in my garage and cannot extend the mast fully. I have the lift jacked up so the the drive spin freely. The voltage at the fuses with accelerator at maximum is 35.4 volts. I disconnected all the connectors from the controller board and sprayed them with contact cleaner. No help, problem still there.

One interesting item is the controller board stills works after it drops the main relay. The motor relay will still energize when you press the accelerator and if you hold it at max the bypass relay will energize about a second later. The motors are not turning because the main relay is not energized.

-MAY-be... have you blown the brush dust out of the drive motors? and checked for shorts to frame on all the power cables and controller heat sinks?
what is battery voltage at rest, -and- when you dead head the lift all the way up, what does the voltage with a load drop to?

Connections to relay are good. When it stops the pin on the controller boards goes to 36v, when running the pin is 0.9v. Battery voltage at the fuses is 36.4v with motor running. The lift sat outside in the weather for several years. The problem is getting less repeatable with time. So maybe the current in the drive motors is fluctuating and the scr circuit is detecting this and feeding the info back to the controller board. As I run the motors more the brushes make better contact and problem happens less. It only does in the slow speed mode. It never stops when the bypass relay is energized.

cheking first the wires from locgic card to contactor coil

i would make sure to have a good battery (doing a relife test). contactor coil (doing a pulling test) and also check the driver output from logic card, directly from pin p2-6 by using a voltmeter.

No the dash readout still reads 9. The line controller relay opens and you have to turn off and back on to reset.

don't you get a code on the dash when it stops running?