attached. (note: the pic is too big for uploading and I don't have the time to resize it right now. The solenoid is small - about 5/8" x 1.5" by 2") I should have taken a wider view to show the filter bowls and tubing. This little solenoid caused me quite a bit of confusion but I finally figured it out. It is just below the manifold switch on the outlet side of my Racor
filters. It was wired to the old Halon/Engine shutdown alarm
system. It was designed to shut off the fuel (diesel) if the alarm
went off (high temp from fire). It has three ports
and you can put tubes in it to do what you want. Mine was plumbed as normally open but could have been plumbed as normally closed, i.e. closed when 12vdc present and open with no power. It could have been done the opposite.
The whole thing must have provided the PO with some safety
peace of mind but I looked at the mess as overly complicated and I ripped everything out except the solenoid which will be a future project
. I contacted the manufacturer and found out that is is very unlikely to fail and go to closed from open.
So the purpose was to shut off the fuel to the main engine or the genset if there was a fire.