Hi all;
	I was doing some work on the bus over the weekend and noticed a 
little module mounted to the top of the engine compartment.  It has a two 
pronged electrical connection and what looks like vacuum hook ups coming 
out of either end.  the small can shaped module is mounted to the drivers 
side bolt that affixes the heater blower to the center of the top of the 
engine compartment.  tied off near the object is a wire that has the female 
end of the electrical connection.  the other end of that wire goes into 
the test block on the passanger side of the engine compartment with all 
the other wires.
	Can anyone tell me what this thing is, how to hook it up, and if 
it is all that important?
All idea's are apreciated.
thanks.
Ed.