4:1 9V Connection to StompSwitch

[JamesMc]

I recently completed building the 4:1 compressor.  I tested it and everything is working fine.  When the enclosure came in on Friday, I boxed it up using the 3PDT #4 with trimmer.  I have used these switch boards with all of my builds so far with great success.  However, on the 4:1, the LED was really dim no matter how I adjusted the trimmer.  In fact, adjusting the trimmer didn't make any difference at all.  So I took it back out of the box and hooked it up to the bench power supply.  The LED flashed a couple of times then went off completely.  I induced a small voltage across the LED leads with my DMM and it still works, so I hadn't burned it out.  Check, trace, check, trace, etc.  No luck.  I finally started checking voltages when I noticed that I had a good 9.2V at the input connections at the board, but only about 4.3V at the 9V+/- pins at the bottom of the board, the ones that go to the switch.  If I checked from the +9V pin at the bottom to the GND pin at the top, I got a full 9V, but when the neg pin at the bottom of the board is in the equation, I get really strange reading, anywhere from 4.3V to 1.8V.
I removed the stomp switch completely and re-connected the board to my test rig, and the effect part works just fine, but the only way I can get an LED to work is by connecting the negative side of the circuit to the negative pin at the top of the board.  For now I'm going to use another stomp switch and skip the #4 board this time.  The effect and the bypass LED will work that way,  But I would still like to understand what is going on.
I'm stumped and any help in understanding what is going on is greatly appreciated.