LM3-S voltage issues, then motor overload -- why?

[ON28]

Today ran my trusty Atlas GP-7 with an LM3-S and KA-3, when voltage suddenly decreased, eventually down to 3 and change, so I shut down. Found a screwdriver partially on the rails, though the PSX circuit breaker did not trip. Restarted and the loco ran a bit, but again showed fluctuating voltage up and down, then to 3 and change again. I tried auto-resetting max motor current (530 Mah) and it reset to 630. Tried to run and got a Motor Overload alert. I ran other locos and had no problem, though this same situation weeks earlier occurred with a Kato F3/LM3/KA4 after it ran on underpowered track, which I have yet to fully investigate. Any suggestions here? Are my modules damaged, or can they be reset? Thanks!

[William Brillinger]

Can you take the KA out and try it again?

[Alan]

Also put a voltmeter across the rails near the loco when it is running correctly and again when it is running incorrectly. Reading same voltage as shown on LM both times?

[ON28]

Turns out a quick look under the hood revealed one wire to the KA had come unsoldered. Fixed it, and added heat shrink to secure. The auto-test set voltage at 550 ma and the unit was released back into revenue service! Thanks to all for the help!