J.P. Instruments » OIL Probe

OIL Probe

Check that thermocouple wire is used between probe and EDM, and not spliced with copper wire. Check reading with engine cold. Check reading in boiling water (212F).

Check wire – insulation broken through – picking up outside voltage. [K-type has only mV signal]

The Oil Probe – p/n 400505 L/C comes in one size: 1/8″ NPT. Continental engines may require a ‘brass’ oil probe adapter. These come in: 1/4″ OD tapered, 3/8″ OD tapered, and 5/8″ OD straight not tapered with 1/8″ ID NPT. JPI has only one Oil probe collar adapter (p/n 400503). This comes in: 5/8″ OD straight not tapered with 1/8″ ID NPT — Cost is: $40.00 [ Contact the Sales Department at 800-345-4574 ]

** We also have a 5/8″-18 NT Oil Probe – p/n 400509 that can be used with EDM’s and Vision Micro units.

EDM-700/800 Pin assignments( 4 or 6 cylinder ):
yel 1, red 2, OIL
yel 3, red 4, IAT (or ‘CARB’ if EDM is for a 7/8/9 cylinder engine.)
yel 5, red 6, CARB (or ‘CDT’ if ‘IAT’ installed)
yel 14, red 15, OAT
yel 16, red 17, TIT
yel 18, red 19, TIT-2 (2nd TIT)
gry 12, Remote alarm (Sinks to ground)
red 13, + Power(Red)
wht 24 , RS-232 data port
blk 25, Engine ground.(Black) ** ( Pin # 11 not used -not used.)

EDM-760 Pin assignments:
yel 1, red 2, Left TIT (or CARB )
yel 3, red 4, Left OIL (or TIT2)
yel 5, red 6, OAT
yel 9, red 10, Right TIT (or CARB )
yel 11, red 12, Right OIL (or TIT2)
gray 7, , Remote alarm ( sinks to ground)
red 8, , + Power(Red)
wht 13 , , RS-232 Data Port Signal
blk 15, , Engine ground(Black) ****(pin#14 NOT USED )

• Temperature may be different from factory gauge because of different location on the engine.

• Check reading with engine cold. Should read close to ambient.

• Check reading by dipping probe into boiling water; should read 212°F or 100°C.

• Check that thermocouple wire is used between probe and EDM, and not spliced copper wire.

• Compare reading to aircraft’s oil gauge. If the readings go very high, the display will blank out.

• Check for a bent or recessed pin on the rear P1 connector.

• Check crimps between probe and harness.