95 volvo 850 turbo vent solenoid and throttle plate location for evap leak smoke test

[legacyhunters]

I want to do an evap smoke test, this project keeps getting harder and harder.

First I can't even locate where the vent solenoid on the car is. One person on the autozone chat told me it was called the EGR vacuum valve. I want to be able to know what this part looks like before looking for it as well and no luck finding a picture.

I want to be able to close the vent solenoid with the volt meter (multi meter) to do the evap test, talks about it on this link http://www.thesmokemachine.com/TechTip% ... 06-06).pdf , on a side note how do I find out which wire is positive and negative (yes there is instructions in the link but its not exact, since I'm new to all of this)

also this other link The Trainer #8: Diagnosing EVAP Systems tells me that I should also close the throttle plate which I just found out today and never even heard of this part.

Thank you to all