An ohm check is always done with all power removed!!

The ohm meter actually supplies a small voltage (from its built-in battery) and measures how much current flows through the circuit:
Resistance (ohms) = Voltage (volts) divided by Current (amps)

Voltage and current measurements, on the other hand, has to be done with power on.

Hope this helps (don't want you to fry your multimeter).

Finn

Marvin Kaye wrote:

Posted for "sqpilot@earthlink" <sqpilot@earthlink.net>:

Yes, Ed....my injectors are also fired by grounding. Don't know if it goes
through a resistor. Just read the manual that says the injectors are fired
by grounding to earth, and that the wiring is not polarity dependent, ie
either wire can go to either terminal on the injector.  Unfortunately, I am
electrically challenged. (I can, however turn on a lightswitch and operate a
radio and a television). Regarding the ohm check....should this be done with
the ignition on or off, or should it be done with the engine running?  I was
thinking that if I disconnect the fuel pump wire so that the engine cannor
start, possibly turning it over and listening to the injectors would tell me
if they are clicking?  Or might this be too diffucult to hear? Thanks for
any and all suggestions on how to check this out.  Paul Conner

 Not familiar with your EFI system, but most
of them turn on the injector by grounding one  lead of an injector through

a

transistor.  So I would check with an ohm meter each pin of that suspect
injector connector and see if one of them is grounded.  Check the "good"
connector to verify that neither side is grounded.

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