It may depend on your meter and how you're testing. Two quick hits from google:

Meter check of a diode : DIODES AND RECTIFIERS

Testing Diodes

I assume that the switches don't work when plugged in and you're now trying to isolate if it's the wiring or the bulb.

I'd put the meter in DC V and check across sockets 4 and 6 in the car. That doesn't help you at your desk though. Got a battery at your desk?

This DIY is also my catch-all for benefitting from someone else disassembling their dash: PeachPartsWiki: Replacing the A/C Evaporator

I'd guess the C124 connector is somewhere near the driver's right foot, based on the presence of numerous blue wires in that vicinity.