Perkins 4-107 Temp and Pressure Sending Units - Testing

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wndsnd

Veteran Member
Joined
Aug 19, 2012
Messages
31
Location
USA
Vessel Name
Largo
Vessel Make
Fales Caribe 30
How do I test the sending units for temperature and oil pressure? I gave the manuals a once over and do not see the procedure.

If it is a drawn out process, maybe someone could point me in the right direction. I am guessing it could be done with a multimeter checking resistance values, but I don't know how to do it.

Basically, I want to test my alarm system. I would like to be able to put it into alarm manually, from both the water temp, and the oil pressure.

Thanks
John
 
Last edited:
Thanks, It is probably easier to change out, but it would be nice to have a test procedure. Will a short to ground from the sensor work?
 
If you want to test the temperature alarm you will have to remove the temp sender and expose it to the temperature at which the alarm is supposed to go off.

If you want to test the pressure alarm you will have to T off the sender with a mechanical gauge and a bleed valve. Crack the bleed valve to reduce the pressure going to the pressure sensor and see what pressure the alarm sounds. The other way is to install the T with mechanical gauge and see what pressure the alarm stops sounding during a start.

Or, remove the pressure sensor, T it off to a mechanical gauge with a tubing connection and use a hand pump of some sort to apply air or oil pressure to see what pressure the switch opens or closes to sound the alarm.
 
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