EMS haywire on external power

dbiddle

New Member
Joined
May 2, 2006
Messages
7
D-180 EMS works fine on internal battery. Turn on external power and CHT's / EGT's go up 100-200 degrees, Fuel levels go to zero, oil pressure off the chart, oil temp down 50 degrees, amps go to 99. What can be checked? What might be wrong? EFIS side still working properly.
 

Dynon

Dynon Staff
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Jan 14, 2013
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14,232
Location
Woodinville, WA
New behavior or is this a new install (and has always worked that way). Off the cuff, either voltage is getting injected somewhere where it shouldn't on the EMS connector that's somehow related to ship's power. Possibly the fuel flow sensor if you're powering it from ship's power instead of the EMS's 12V output. If this is new behavior on an existing installation, has anything changed the aircraft recently?
 

dbiddle

New Member
Joined
May 2, 2006
Messages
7
I have been using the D-180 for several months, but RMI Amp sender would not work and MAP indication would jump around so i changed out from the Rocky Mountain amp sender to Dynon shunt and MAP sender to Dynon MAP. I re-checked the 37 pin connector and everything looks right. Have i reversed AMP + and AMP - ? Something with the MAP wiring? Which misswire would make this happen? Thank you for monitoring this forum and for any direction you can give me.
 

Dynon

Dynon Staff
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Jan 14, 2013
Messages
14,232
Location
Woodinville, WA
Is the amps shunt on the positive side of the electrical system? If not, that can mess readings up. Also, sometimes people get the A/B/C connections on the MAP sensor mixed up. That can mess up the 5V line, which is also an internal reference. That can also have odd effects on readings.
 
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