Michael Benno

I am getting ready to reconnect my tank vent. It was mysteriously cut by one of the PO's (see post https://rennlist.com/forums/928-foru...nected-to.html)

I have a new connector thanks to Roger, now I just need to figure out which side the red wire connects to. Since there is + and - going to this device, I am concerned if I connect it incorrectly it will work opposite to the intended function.

Here is a pic what my current situation:


Does the red go in the left or the right position?

Here is a diagram showing the tank vent solenoid valve system


Here is the wiring diagram (no help)



Your heal is greatly appreciated.
88 S4

RFJ

wow why would anybody do that?even a po?

FLYVMO

It may be an optical illusion, but I would be even more worried about the area circled in red. Looks like the bolt is rubbing on the fuel line.

Cheers!
Carl

Michael Benno

Good catch. since taking this photo I have shortened that bolt and replaced the fuel line.

Still hoping Ing some can let know which post the wires go to.

G.P.

Michael,
You could try disconnecting the solenoid and blow air through it to see how it operates without power connected, then connect 12V to the terminals and see what happens. You can then reverse the polarity to see if there is any difference.
I think these solenoid's are normally closed (cannot blow air through without power being connected) and open when it receives power from whatever relay drives it (probably an impulse, not steady power). It could be the opposite.
It's also possible that the polarity does not matter. Doing a 'bench test' as described above will confirm this.
I found that my solenoid was clogged with carbon particles from the carbon filter in the guard (fender) because the vacuum unit between the solenoid and charcoal canister needed to be replaced.

Schocki

Polarity does not matter in this case. As soon as current flows through the solenoid it will create a magnetic field and close the valve.

Michael Benno

As I am updating this post I am seeing Schocki's comment :banged: Duh, of course you are correct. I didn't see your post but figured it out by pulling the valve and testing it's function with a 9v. Open with no voltage. closed with voltage.

I spliced in the replacement connector supplied by 928srus buttoned everything up. So thanks for all your help everyone. That is one less PO mystery mod resolved. Now on to the next one....

Spider4me

Great Blog site as well. Very helpful!