1973 Chieftain Voltage Limiter

[Ryguy]

We were chasing a problem with the auxiliary fuel tank gauge and something happened to the voltage limiter.  Before the failure, checking output side caused test probe to flash and all other gauges worked.  Took dash screws out to be able to see some wiring better (batteries disconnected), reconnected batteries and ended up with a blown fuse for gauges.  Replaced fuse and gauges peg out.  I now have 11.8 volts in and out, test probe won't flash.  Found a part number on here and got a new one from NAPA.  It does the same thing.  In addition, I tried using the test probe to ground the housing and it lights the probe (probe grounded to steering column bolt).  Not sure if I'm fully understanding how it should work or what.  Would appreciate some guidance.  Thanks!!