OEM knock sensor test help please
 

i am really scratching my head reading and re-reading the shop manual on what should be a very simple test proceedure:

here's the manual:

Knock Sensor inspection (on vehicle)

1. connect voltmeter(-) terminal to the MEN terminal of the data link connector.
2. connect the data link connector terminals TEN and GND by using a jumper wire.
3. turn ign switch on.
4. lightly tap on the engine hanger with a hammer.
5. verify voltmeter indicator moves.
6. turn ign switch to off.

i get nothing on the voltmeter.... but doesn't the voltmeter positive lead need to be connected somewhere????

i have gone thru two knock sensors in a short period of time. any ideas?

thanks for any help.

howard coleman