New EGTs odd

[SammyQ2]

I just changed out all my EGTs & CHTs with new probes. Everything seems fine EXCEPT, when I switch on the D180 EGTs 2, 3, & 4 read room temp. EGT#1 reads -99. Is that normal? Since I'm in the middle of my annual, I haven't run the engine yet, with the new probes.

I double and triple checked the wiring.

Thanks.

 

[dynonsupport]

No. It should read ambient if connected. What you're seeing is normal for a disconnected or failed probe, though. Or maybe a broken wire.

 

[SammyQ2]

What would be a proper check of the EGT? An ohmmeter value?

 

[dynonsupport]

-99 usually means one or both wires are no longer connected to the EMS.

First check the two wires going to the EGT probe with an ohmmeter. It should read basically zero. All you're looking for is good continuity across the EGT probe (they aren't resistive devices).

If the EGT reads good on an ohmmeter, you need to chase the rest of the wiring up to the back of the EMS. You can also swap two EGT probes to help chase the problem.

 

[jakej]

If the solution is at the Dsub end then this is a common problem - ie the pins , especially 13 & 25 in your case, can retract just by moving the wiring loom. Remove the connector and flex the wiring loom while watching the pins, you'll see what I mean.

Jake J