J.P. Instruments » Carb Probe

Carb Probe

EDM-700/800 PIN ASSIGNMENTS:
yel 1, red 2, OIL
yel 3, red 4, IND
yel 5, red 6, CARB (or CDT)
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
wht 24 , RS-232 data port
blk 25, Engine ground.   ** ( Pin # 11 not used.)

EDM-760 PIN ASSIGNMENTS:
yel 1, red 2, Left TIT (or CARB)
     * (See Pilot’s Guide under “Changing the Alarm Limits”)
yel 3, red 4, Left OIL or TIT2
yel 5, red 6, OAT
yel 9, red 10, Right TIT (or CARB) * (See Pilot’s Guide under “Changing the Alarm Limits”)

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 )

Check for copper wire substituted for thermocouple wire. Check at ambient and test by putting probe in boiling water – should read ~212 F (100 C).

Connect Carb probe to pins #5 and  #6, NOT pins #3 and #4 on the P1 connector. [The Install Manual designates pins 5 and 6 under ‘CDT’.] Now Power back up. If it now reads ‘CRB’, but is giving an ‘Open Probe’ message for the ‘IAT’, then the EDM will need to be ‘Reset’. After resetting, be sure to power off and then power back up.

If IAT probe is connected (pins 3 & 4) and if a probe is connected to pins 5 & 6 the unit will display CDT. If only using pins 5 & 6, CRB will be displayed. TIT is irrelevant.

The wires are reversed. Yellow needs to be joined to yellow, red to red.

Could be a length of regular copper wire between connections.

The Carburetor Temperature Probe (CRB) probe, is installed in the Carburetor throat. The CRB probe has a captive 1/4-24 boss that is screwed into the carburetor throat.

Above or below the throttle butterfly on SOME carburetors. ‘Marvel’ carburetors have a 1/4-24 threaded plug in the neck. Remove and place the probe in that location.

The Carburetor Temperature Probe (CRB) probe, is installed in the Carburetor throat. The CRB probe has a captive 1/4-24 boss that is screwed into the carburetor throat.

Use the J1 connector harness and insert the yellow wire into the connector pin 5 and the red wire into pin 6. All wiring must be type K thermocouple wire. Do not splice ordinary copper wire in any temperature probe circuits.