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.