hello guys. planning to put in a tachometer on my truck but i need to check first if the sensor on the pump is good.

here's the sensor: borrowed this pic from a site. i just forgot the name of the site. anyway credits to the owner of the pic.
http://cdalejef.smugmug.com/Trucks/M...t1748115-L.jpg

can it be tested with a handy multimeter (resistance/continuity, etc. tests)??? if yes, should the engine be running or not when testing the sensor?

say, if the sensor is good, what specific type of tachometer should it be hooked up with?

thanks for your replies.