No errors but no go

I have a 2002 Gem that I bought a little over a year ago with about 700 miles on it. I installed new gel batteries and a Delta-Q charger and have had over 1,000 trouble-free miles as a daily driver. Came to a stop sign this week and it just quit. Wouldn’t move (well, until I pushed it out of the street) and didn’t make a sound. The display works and there are no error codes. I have the Repair and Maintenance-Service Manual and I’ve gone through the checklist for the Drive and Power System Troubleshooting. When I turn the key on I get the expected -04 error which goes off when I release the handbrake. I hear the expected “Clunk”. With no error codes, I ran the following steps with a volt meter. At steps 4 and 5 I get 78V. At step 6 I get 76V. At step 6 at the Motor Controller B+ connection I get 77V. The chart tells me this means I need to replace the controller. Before spending a lot of money, I’d like to consult the experts here to confirm I’m testing correctly. The connection at the top right of the controller is labeled B- on the cable. I am assuming the connection on the left is B+ but I’d like to confirm as it isn’t labeled. Also, are there any further tests I can do to confirm I really need a controller? I’d hate to replace it and still have a problem.

Does anyone recommend smacking the side of the motor with a hammer to see if a stuck brush falls back into place?

Unlike later model motors which have a removable venting band so you can see and service the brushes, the earlier model motors are a bit of a PIA to deal with.

Also, has anyone used an Ohm meter to measure continuity through the brushes to verify none are stuck?

FYI, I had a car many years ago which would not turn over the starter motor every now and then. But an old ax handle and a 5lbs sledge hammer got me back on the road many times. Also loved the looks when people would see me whacking what they thought was my engine.

I highly recommend driving over the top of 00-04 gems with a bulldozer

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Yeah, that was funny the first dozen times. Not so much anymore.

I would imagine something like stuck brushes in the motor would at least make a sound. No? I get nothing, as if something just came disconnected. If that something is a failed component inside the controller, then I’ll deal with that. Just want some kind of verification if possible.

Most controller problems set a fault code.

Ohm out motor.

Check wires at controller, but first clean and lube them as per ge manual.

Pins to measure.
1 and 2 need b+

Then check forward or reverse wire for b+
All are active high iirc.

The start switch p 3 when pressing throttle.

From memory. Look up the pin numbers.
Chack in circuit by piercing insulation near controller.

That’s just like, your opinion man…