4RJN Posted July 4, 2021 Report Posted July 4, 2021 Hi I just purchased this plane a few months ago and I cannot figure out where the problem is. The plane is a 2006 CTSW with Dynon D100 and D120. Briefly the engine warning light comes on after different amounts of flying times and conditions. It seems very random. The sensors that trigger the warning are BOTH CHT sensors and Engine oil Sensor showing high temps in the red for a brief second at exactly the same time and then return to normal. We have cleaned the connections on all sensors, all ground wires, connection to the back of the D120, and visually inspected all wire looms. Any suggestions would be appreciated. I am attaching short video to see the issue. warning light ctsw.mp4 Quote
4RJN Posted July 5, 2021 Author Report Posted July 5, 2021 My understanding of the gauges would be that in order to peg them to full RED they would be shorted to ground. If they are loosing a grounding connection wouldn't the CHT and Oil Temp go to zero? Quote
Madhatter Posted July 5, 2021 Report Posted July 5, 2021 Roger is absolutely 100% correct. I've been working with avionics for over 40 yrs, any partial grounds will screw the whole system up. I hate all the spade and butt connectors in the CT, they all have a potential for resistance, these I've changed in mine. Grounds are just as important as A+. Tighten everything. Quote
GlennM Posted July 6, 2021 Report Posted July 6, 2021 Is the Dynon EMS case grounded to the main ground mounted to the cockpit side of the firewall? I had to add a wire. It solved my oil temperature bounce. Quote
Anticept Posted July 6, 2021 Report Posted July 6, 2021 On 7/4/2021 at 8:26 PM, Roger Lee said: Go to these sensors in the engine compartment and if the wire connector moves easily squeeze it with a pair of pliers to tighten them. Also you probably need to tighten the ground and that's the bolt on the top right side up above the white engine mount that goes through the firewall. There are 5 grounds that emanate from the battery terminal. Tighten those too. Call me for a more detailed explanation. If this is a CT still with the old style firewall protector, then their grounding bus bars may also be loose. I was chasing down issues on an 08 CTLS for months, and finally found that the screws were not tight. Those vibrations cause all these subtle problems such as alarms as shown. Quote
4RJN Posted July 7, 2021 Author Report Posted July 7, 2021 Thanks for the input so far. I will continue to chase down the issue as these have not resolved the problem. Quote
Anticept Posted July 13, 2021 Report Posted July 13, 2021 Also if you know how to, do voltage drop tests. It is the only electrical test that can't lie. Quote
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