NC Bill Posted April 29, 2018 Report Share Posted April 29, 2018 My temp readings on #1 are erratic. They go from ZERO to RED LINE but seldom are in line with normal #2. Usually the bar is just fluctuating back and forth or just blank. What 2 points is the probe connected to. I assume 1 is on the engine and the other on the back of the SKYVIEW. Any suggestion short of replacing the probe appreciated. Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted April 29, 2018 Report Share Posted April 29, 2018 Hi Bill, Which sensor are we talking about? Sounds like you're describing a CHT? Nothing on front right #1. Rear right #3 has EGT and CHT. left side #2 cyl. has CHT and left side rear #4 has EGT. If this is a CHT sensor that is either on #2 or #3 cyl. bottoms then just try giving the connector a good squeeze with a pair of pliers. The connector should not wiggle and flop easily. It should have some friction side to side. Quote Link to comment Share on other sites More sharing options...
ODowneyEng Posted May 1, 2018 Report Share Posted May 1, 2018 That solution worked for me recently. While at it, clean the voltage Regulator and secure with two wire ties. It is a matter of time before that beggar acts up too. Roger you are the man with the Midas touch. Quote Link to comment Share on other sites More sharing options...
NC Bill Posted May 2, 2018 Author Report Share Posted May 2, 2018 Sorry to say Roger, but tightening didn't solve the problem. Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted May 2, 2018 Report Share Posted May 2, 2018 It doesn't always solve the problem, but you have to start on the most common, cheap and easy solutions for the diagnostics and then work your way through and try not to skip around too much. You want to start at "A" then B<C<D and so on. If your diagnostics aren't complete and follow a logical pattern you may miss the cause. Follow that CHT wire and make sure it hasn't rubbed through against the engine somewhere or the connector at the probe isn't partially broken. Next it would be grounds through the system which are easy to check and even take a wire a try grounding the EMS on its frame. This complete ground check should take about 20 minutes. Tighten them all. Quote Link to comment Share on other sites More sharing options...
cdarza Posted September 4, 2020 Report Share Posted September 4, 2020 I replaced my old (fluctuating) CHT 1 1/4 gauge part N12116V300F020 with a UMA N12116U300F000 I thought it was gonna be a simple plug and play replacement but im now getting a 300F reading just a few mins after startup. Gonna go back to hangar tomorrow and try to figure this one out but any chance i replaced with the wrong incompatible part? Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted September 4, 2020 Report Share Posted September 4, 2020 Either it isn't compatible (not likely since FD has used UMA) or needs a resistor in line or check the wiring. Quote Link to comment Share on other sites More sharing options...
cdarza Posted September 5, 2020 Report Share Posted September 5, 2020 I tried the new CHT gauge to the oil temp line and same prob - 170 degrees (switch on without engine running) Am not good with electrical. Does this now sound like a resistor needs to be added then ? Sadly that would make the cht /oil temp not interchangeable (for testing purposes) Argh. Will reach out to FD or UMA but any other thoughts here are appreciated. Quote Link to comment Share on other sites More sharing options...
cdarza Posted September 10, 2020 Report Share Posted September 10, 2020 Update FYI. Got response from UMA. The new gauge i bought is not calibrated to the existing probe. Original from FD N12116V300F020 New part: N12116U300F000 The key difference is the V and the U .... ARGH!! Frustrating expensive mistake for people like me that are not very knowledgeable on this. Cheaper alternative is i shall like replace the probe to match the gauge. Quote Link to comment Share on other sites More sharing options...
cdarza Posted August 19, 2021 Report Share Posted August 19, 2021 Was having some elevated CHT gauge reading issues again - With Rogers guidance, i once again cleaned and tightened the grounds. Thus far ground run has been good. I did notice however when i turned off the Dynon 100/ transponder and radio, the CHT went down 5 to 7 degrees. (UMA Analogue gauges) Repeated this multiple times by switching the EFIS etc on then off and got the same results. You electrical geniuses will know whats going on - for me, its just another CT quirk :) Quote Link to comment Share on other sites More sharing options...
GlennM Posted August 19, 2021 Report Share Posted August 19, 2021 Grounding the EMS case to the main ground behind the panel solved years of issues I had with the oil temperature and CHTs. I would recommend looking for the ground wire or installing one because it worked so completely to fix my problems. Quote Link to comment Share on other sites More sharing options...
Anticept Posted August 27, 2021 Report Share Posted August 27, 2021 Dynon even recommends case grounding in the install manuals, and it's really irritating that this isn't done from factory. That said, I'd even say further that if the case itself isn't grounded internally, I'll fault dynon even more. Quote Link to comment Share on other sites More sharing options...
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