PS-3 Quirk

Seems all transformers don't run everything ... well.

I have noticed differences in conventional with conventional engines.

Some transformer will only run the engine and do nothing else or have quirks.

Depends on the match-up ...

A KW runs PS-3 in DCS mode with no problems.  I've never run one in conventional mode.

What version TIU is he using?  Are you sure the contacts inside the KW are correct?  Did you change the whistle rectifier in the KW and, if so, recheck the wiring.

Apparently the PS3 engine is detecting a DC offset on the track voltage during a direction change or throttle closure.  You could confirm this by putting a meter in DC-Voltage mode across the track and note the DC voltage (and polarity) under these conditions.  As some power sources require a minimum load to "behave" properly it seems like a light bulb (or lighted lock-on) is an expedient solution.  As opposed to, say, trying to modify each PS3 engine.  During the direction change or throttle closure, the PS3 reverts to its on-board supercapacitor for power and hence the load may drop below whatever minimum the transformer needs to behave.

Thanks for the replies! The loco owner doesn't use DCS, he uses the KW with a bell button from a T-1. I didn't find any DC current showing on the track when activating the direction button, and there is no AC voltage at all when the direction button is pushed.