we are measuring the voltage of the wire/plug that sits on top of the vapor canister with a multimeter...the meter stays at zero like the wire is dead...my hubby says that we have to turn the ignition on first and then measure the voltage but i say we dont have to...who is right?

thank you

 

I believe you have to turn the ignition on to activate the solenoid, to open the valve so the engine pulled the vapors to the engine to burn them off when started.


See diagram

 

hello

thank you for the note back.....to measure the volts on the plug that plugs into the purge solenoid canister.....we put the positive probe on the green wire connector inside the plug (i traced that and it goes back to a relay on the firewall) and then we put the black test lead on a metal body part....the ignition was already on but nothing is registering on the multimeter we have it on the 20 volts lowest setting...did we do this right?

thnk you

thank you

 

I am curious of this as well. Power would only be applied when the computer told the purge valve to open, but what circumstance is that?

 

According to the diagram above, you should have a pnk/blk wire which should have battery voltage with the key "on" (run position). That supplies power to the solenoid for the canister purge. The power then goes through the coil of the solenoid to the grn/yel wire and on to the ECM which grounds the wire to turn the coil on. If you have the connector unplugged from the solenoid, you will not have any voltage on the grn/yel wire, only the pnk/blk. You can either use an ohm meter to see if the solenoid is "open" or easier yet is to plug it back in and see if you get voltage at the grn/yel wire. Do both tests to be sure but I would guess the solenoid is bad. HTH!