without any locos or cars with lights on the track, the ammeter should indicate zero. if it doesn’t, there’s a low level short in the trackwork that needs to be tracked down and fixed.
if it is the loco, which he said runs at low speed, then you might expect it to indicate close to shutdown current before increasing the speed and seeing the PowerCab shut down. this would suggest there’s a problem with the loco. most HO locos don’t draw more than 1A
if it indicates relatively little current, 0.2A, just before increasing the speed and causing the PowerCab to shutdown, it may be due to a faulty power supply that isn’t supplying whatever the PowerCab is rated at (~1.3A). the power supply voltage is dropping at a relatively low current causing the PowerCab to shutdown because of insufficient votlage, not excessive current
Wow, two pages of speculation over six days and the OP still hasn’t confirmed that the original power supply is working properly (supplying the correct voltage/current under load.)
Until he does, all this speculation is nothing but, well, speculation!
And there are at least a few reports from PowerCab users on the NCE list on groups.io about having to use “other” power supplies after the one that came with their now-out-of-warranty PowerCab has died. Since NCE doesn’t make those power supplies available separately, those out-of-warranty PowerCab users really have no other choice. And since the OP stated he’s still on the 1.28C firmware, we can be pretty sure (Yeah, I know - More speculation!) his PowerCab is out of warranty…
You are both correct, the P114 is readily available. I was apparently going on unverified information, which I should not have done.
However, the two replies to my post seem to have completely missed or ignored the main point - Regardless of whether or not a replacement is available, until the OP confirms that his existing power supply has been tested to be operating correctly under load, all else is merely speculation.