Polar Express lighting puzzle

Just a guess but this may be because the Z1000 output is AC whereas the PE wall wart output is DC.  The LED doesn’t see the correct polarity with the PE transformer while the LED sees the correct polarity for one half of the AC cycle with the Z1000.  If possible connect the Z1000 to the Fastrack to confirm this is the problem. 

Greg has your answer, it's designed to be an AC bulb and they didn't use a bridge rectifier, but just a diode.

Well guys , 

The headlight still works with the same type of LED .  ( I'll have to find the post that I showed a photo of one of these plug in  LEDs when I had one apart and show it on this thread . )

I think you have given me the answer though . 🤤

  Ill have to take the PE apart and solder the wires on the cab  light in reverse.

  I didn't think about the AC / DC because I never needed to care about polarity on the DCS .  I do remember using your rectifiers for the passenger cars John, and I had to make sure I soldered the the wires correctly for polarity.

 I  probably soldered the wires correctly by accident for the working headlight LED and not for the cab LED.

 I can't wait to get the  PE opened up again .    Still learning.🤔

Thanks  Greg and John.      

The  LEDs in question.

And there you have it.  That will work with only one polarity.

Yep John ,

You are indeed right  .   I'm getting to think I need to get the LOTTERY numbers I need so I can pay for your tuition at MIT .🏛🤓

Really though , you and Greg , have put me on the right track again.    Thank you.

Judy's  PE. Will now be more fun for her at Christmas .

Our  LADY QUEEN of VICTORY , pray for us.