How to diagnose the ACCII?
 

How can you check in the junkyard if the ACCII you just found work or not?

I found one yesterday in a yard inside a 1980 300sd, it was the first time i found one without cracks.

Same question for the corresponding amplifier under the dash.

I'll need to review the manual when I get home... but you need to apply 12V's to 2 of the pins to allow the valve to fully open with a "clunk noise" then reversing the polarity closes it, another pin put it halph way in between. I'll see if I can dig up the George Murphy document tonight.