lagasse@biomed.UUCP (Robert C. Lagasse) (05/23/85)
Reply to Jim Seavey @ Pacific Bell , San Francisco:
Parts list for pressure switch installation:
1-Tee connector for 3/16" ID hose x 3/16" ID hose x 1/8" ID hose
1-24" lenght of 1/8" ID rubber hose (auto vacuum line)
2-Slide-on crimp terminals, female, 1/4"
1-lenght of 2 cond. wire from engine to dashboard (or single cond. if you
ground one side of the switch to the engine).
1-pressure switch , Herga model #6731-06 or #6731-10
Misc.- Piezo buzzer, 12v pilot light, crimp terminals, wire ties, etc.
For OMC: Find the 3/16" hose running to the water indicator (pisshole), cut
it near the indicator and insert the tee inline using the 3/16" ends. Next,
connect the 1/8" hose from the 1/8" tee connector to the input port on the
pressure switch. Mount the pressure switch up high so water will not try to
collect in it. The switch has a nylon body and is featherweight so you can
just glue it to something plastic with a good contact adhesive or
cyanoacrylate. The pressure switch has a recessed screw which provides a
nice linear adjustment. The switch which I used was the #6731-06 which has
a pressure range of 0.2-1.7 PSI. You might want to try #6731-10 which is
0.75-2 PSI as I did not get the full adjustment range I expected since the
engine idle pressure is higher than what I thought it would be. I will
probably change to the #6731-10 eventually. These switches have neoprene
diaphragms and the actual switching mechanism is a "microswitch" that has
SPDT (form C) contacts. Order the switch from:
Pres Air Trol
895 Mamaroneck Ave
Mamaronect, N.Y. 10543
(914)698-2026
Good Luck! Would like to hear about any results!
Bob Lagasse biomed whj12