Ahhh the ole code 24

"-24" means there is an open circuit in the main drive circuit when it should be closed (voltage at T2 is less than 88% or something like that).

So basically the question you ask is "is this happening in both directions?"
no one direction only- most likely the F&R contacts have an issue (burnt, welded), less likely but I have run into it: the card has a bad track for a direction (when the contactor won't operate). To determine which is the case an easy test is to swap wires 27 & 23 at PB4 & PB5. This will cause the truck to operate in the opposite direction selected so lift up your drive wheels. If the problem stays in the same wheel direction, the issue is the contactors or the associated wiring. If the problem changes wheel direction, the card is bad. To get the EV100 pin release tool order an A B Y or Z plug kit, they all come with the tool.

Yes the problem is in both directions - Check for an open motor circuit. Check your brushes, connections at the motor, the heavy connections on the control panel (contactors), also a culprit often overlooked is the RB contactor (regen). It must be closed while in normal driving operation. Check it for proper operation and that the tips aren't badly burnt as they do get a walloping.

Those TCMs, aren't they fitted with EVT100 panels (transistorized version of the EV100)? Not that it matters for this code but for others it certainly would.

the pot most likely didn't have anything to do with it, and it is actually my W.A.G. that your problem is related to the guide pin in the bottom of the armature of the forward contactor, and it causes an intermittent bad connection in the "at rest" position of the forward contactor when you try and drive in rev, the fact that the connection takes longer to "make" than it should is where the code 24 is caused. it could be in a bunch of places in that circuit, that is just a w.a.g. with some experience behind the guess

Hi,
Thanks for the input I replaced the contactor and will just wait and see if that fixes it. What I can't understand though is how adjusting the accell pot made it go away last time since the pot should have nothing to do with the T2 voltage.

Being intermittent does make it sound like the contactors.

Also, bad drive motor brushes can give you this code but usually the problem keeps getting worse until it's happening almost all the time.

replace the directional contactors, and check all power cables for acid damage, replace any cables that the insulation is not perfect.