[cessnadriver]

CJORDAN.
Yes the up locks are in series so if one of the switches don't close the "cycle" is not completed and you'll not get the green light and or doors closed. I assume you have electric/hydraulic pump so the pump will continue due to the incomplete gear cycle. My 65 C337 has a mechanical pump and the only way you know the system is STILL pressurize is the handle does not return to neutral and if allowed to continue you'll smell over heated hydraulic fluid. As an A&P mechanic I installed extra wires (parallel) to each of the up lock switches ran those wires to three small switches that I can plug in from the cockpit and check each up lock switch individually, by isolating it (close). Works GREAT and no need to worry about doing a FAA Form 337 since it's only used as a testing device. I did log the wire modification in maintenance log book, as a owner produced part if asked by FAA, which will have to be remover prior to sell my airplane.
Hope this helps.
Regards, BILLS.
C337 owner, pilot, A&P mechanic.