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 )

Check voltage on pin #5 of the FF pig tail – should be around 12v. Also check the voltage on pin # 4(signal) should be around 5v. If this checks out OK, but his voltage on the red wire out at the transducer end is low or next to zero, then his FF harness is grounding out somewhere between the EDM , wing, or engine. If he sees 12v on the short FF harness off the EDM in the cockpit, but plugs into this the FF harness from the engine -either one or both that goes out to the transducers on his left or right engines, and the voltage drops on that red wire down to zero, then he has a short. The insulation on the red wire could be shaved off durning the install or vibration, and making wire-to-metal contact – grounding out.

Can call for the FF Tester. This costs $35.00 and will check the harness and EDM for correct operation. Please call the Sales Department at: 800-345-4574.

It is better if the EDM is grounded at the engine case(not in the instrument panel). Do not use panel ground, battery ground, or airframe ground. Airframe ground can vary from engine ground by 1/4v. This could cause the EDM to show too ‘High’ or ‘Low’, EGT, CHT temps. Or show ‘Unsteady’ readings. This is easier said than done on a twin. So If grounded to the panel, to check if this ground is OK, use a digital voltmeter to measure the difference between the EDM ground and the engine block ground. If the difference is greater than 0.5 volts with the alternator charging, then remove the EDM ground (black wire) from instrument panel and connect it directly to the engine block ground or other ground point.

EDM-760 needs 11.5v for the display to come up. Less than 11.5v you will see only “JPI”.

EDM-760 Pin assignments on P3 connector:
yel 1, red 2, Left TIT
yel 3, red 4, Left OIL or TIT2
yel 5, red 6, OAT
yel 9, red 10, Right TIT
yel 11, red 12, Right OIL or TIT2
gray 7, , Remote alarm ( sinks to ground)
red 8, , + Power
wht 13 , , RS-232 data port
blk 15, , Engine ground ****(pin#14 NOT USED )

1. Go to pilot program mode (Hold both buttons to see PROGRAM).
2.Tap STEP until you see DUMP? N.
3. Hold both buttons until you see ‘RCRD TIME 6 SEC’. Tap the LF to change recording rate.
4. Tap STEP and you will see ‘MNTH’. Use the LF button to change.
5. Tap STEP to set ‘DAY’, LF to change.
6. Repeat for ‘YEAR’, ‘HOUR’, ‘MIN’.
7. Tap STEP and see aircraft ‘N’ number, or EDM serial number.
8. To change or add ‘N’ number, hold both buttons until the first character flashes, use LF to change. Tap STEP to move to the next character. LF to change. To exit, hold both buttons down until you see ‘END Y’.
9. Tap STEP to exit, and then power off the EDM.

Swap connectors for ‘Left’ and ‘Right’ engine to see if the problem moves to the other side of the display. If it does, check wiring and crimps. If not and stays on same side, then send in EDM for repair. Visit: https://www.jpinstruments.com/jpirma/for a RMA number and shipping instructions before shipping.

Last item on FAC LIM menu (see Pilots Guide) adjusts the light level. Ex: ‘MIN DISP BRT 12’. Can be set from 0 to 31.

Here are some ballpark numbers: ( remember each aircraft is different.)

For an EDM-760 it takes about 30 hours; add 6 -10 hours for fuel flow.

* Times will vary with each aircraft. *