Thread: Dynon interesting happening...

I have a customer with a fairly new CTLS. During a flight some very strange things started happening with the Dynon Engine monitor. A while after takeoff, the customer noticed that the engine readings started becoming erratic, and the master caution light would start flashing on and off. The main instruments were fuel pressure, oil temp and pressure.

In addition, there was oil coming down the left side of the cowl. We got the plane back in the shop and found that the magnetic plug was leaking. We replaced it with the new hex head style, torqued and safety wired it, cleaned up the oil mess and sent him on his way.

Soon thereafter he was back still with the erratic instruments. We cleaned the engine again, concentrating on the radiator, confirmed that the leak was stopped, cleaned the oil pressure sender, and again sent him on his way.

Better, but no cigar! Not to be out-smarted by a Dynon, I traced every sender, and found the oil temp sender wire was a bit corroded, and the fuel pressure sender a bit loose. Fixed both and ran up the engine and it all seemed better. OK time to fly. I flew the plane for an hour and all was steady, and accurate.

Summation: It seems that the Dynon has a common grounding system, and when the oil from the magnetic plug got on the oil pressure sender, it "stressed" the other two items in the indicating system, sending them into their fit. All clean and tight and all is well. So, if you have erratic indications on your Dynon, check every sender in the system.

Happy flying.

A few months ago my factory "steam gauge" CHT started giving nonsense readings and going into the red as soon as I advanced the throttle a little. I called Tom Dunham and he advised removing the connector from the sensor, tightening it up with a pair of pliers and reinstalling it. Problem went away and stayed away. I've never liked those style wire connectors, not on industrial electronics and especially not on airplanes.

Kind -of along the same lines, I was enroute from Cheyenne to Afton and my Flydat started reading all over the place. The oil temp was all over the place. I contunied the flight based on CHT and oil temp were good. What it came down to was poor connection at the probe.

Just out of annual, our Dynon EMS started giving erratic ammeter readings. The graphic indicator is NEVER steady, but bounces around continuously in the green and into the yellow both high and low. The alarm goes off FREQUENTLY, primarily with "Low current alarm" messages, but maybe 1 time in 10, or so, it goes off with the "High current alarm" message! What does that sound like to you? You might wonder why we haven't simply taken it back to the CT Service Center which did the annual, but it's a long way from where the a/c is based, and this just happened. I flew a long x-c last weekend (5+ hours each way) and those alarms were going off AT LEAST 20 times per hour. BTW, in the course of the annual, the engine and all accessories were removed and re-installed in connection with installation of the firewall blanket. Does this sound like loose wires or defective senders , or what? We'll appreciate any thoughts you have to offer.
Thanks.

About 10,000 years ago I used to be an electronic technician, and I know Zip about Dynon products.....but on first glance, you have a loose wire. If it was a bad sender, you'd likely get an incorrect reading most all of the time but instead, you get a bad reading some of the time.

Originally Posted by CT Newbie

erratic ammeter readings. The graphic indicator is NEVER steady, but bounces around continuously in the green and into the yellow both high and low. We'll appreciate any thoughts you have to offer.
Thanks.

I had a StingSport in with these symptoms - I found the battery was internally shorted. I replaced the Battery and the charging system returned to normal. The customer keeps the battery constantly plugged into a "Battery Minder" as he is an infrequent flyer.

Originally Posted by CT Newbie

Just out of annual, our Dynon EMS started giving erratic ammeter readings. The graphic indicator is NEVER steady, but bounces around continuously in the green and into the yellow both high and low. The alarm goes off FREQUENTLY, primarily with "Low current alarm" messages, but maybe 1 time in 10, or so, it goes off with the "High current alarm" message! What does that sound like to you? You might wonder why we haven't simply taken it back to the CT Service Center which did the annual, but it's a long way from where the a/c is based, and this just happened. I flew a long x-c last weekend (5+ hours each way) and those alarms were going off AT LEAST 20 times per hour. BTW, in the course of the annual, the engine and all accessories were removed and re-installed in connection with installation of the firewall blanket. Does this sound like loose wires or defective senders , or what? We'll appreciate any thoughts you have to offer.
Thanks.

I had this problem, too. Lockwood replaced a fuse and the problem went away. You can try searching this forum for which fuse. I can't remember.

Glenn,

Was the system like this before the firewall blanket? If it wasn't then it sounds like a bad ground. That's where I would start is all the grounds.

The fluctuations started after a year of ownership. My CT had the firewall blanket installed from the factory. so the fluctuation was after. I searched and found they replaced the Dynon ammeter fuse. No problems since then, which is over a year. I am not sure about CT Newbie's fluctuation, though.

I would look at my ground wire attachment points and put a wrench on them no matter what to check for snugness. Then all my fuses. I would bet it's a connection and wiring ghost are the hardest to find sometimes. A wire may have become pinched some where? You just never know for sure.