gras747 Posted October 2, 2023 Report Share Posted October 2, 2023 Amps spike to the redline and cause engine warning then immediately return to normal. No breakers tripped No smoke Anyone? Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted October 2, 2023 Report Share Posted October 2, 2023 Check you grounds, and clean the connections on the shunt. Quote Link to comment Share on other sites More sharing options...
gras747 Posted October 2, 2023 Author Report Share Posted October 2, 2023 Thank you Will do Quote Link to comment Share on other sites More sharing options...
Garrett Gee Posted October 2, 2023 Report Share Posted October 2, 2023 4 hours ago, Tom Baker said: Check you grounds, and clean the connections on the shunt. Second this. This seems to happen to me about every 12-18 months, and cleaning the small wires to the shunt and hitting them with a little dielectric grease has always worked for me. Quote Link to comment Share on other sites More sharing options...
cdarza Posted October 3, 2023 Report Share Posted October 3, 2023 Every now and then the grounds/connectors need to be inspected and cleaned. I recently have the CHT/OIL temps going from green to red when i PTT. Usually the cleaning keeps this from happening for about a year. Quote Link to comment Share on other sites More sharing options...
Animosity2k Posted October 10, 2023 Report Share Posted October 10, 2023 On 10/2/2023 at 7:38 PM, garrettgee2001 said: Second this. This seems to happen to me about every 12-18 months, and cleaning the small wires to the shunt and hitting them with a little dielectric grease has always worked for me. What is a shunt? Quote Link to comment Share on other sites More sharing options...
Anticept Posted October 10, 2023 Report Share Posted October 10, 2023 A super low resistance bridge. It causes a tiny bit of the electrical flow to go into an ammeter without actually splicing it directly into the wire. They look like this: Below is the "water analogy" and a simplified electrical schematic: Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted October 11, 2023 Report Share Posted October 11, 2023 I've had amp spikes in the past. I was told by Dynon to remove the 4 wires and clean them with a scotchbrite pad. Then apply a tad of dielectric grease on the terminals and re-attach them. It only took a few minutes. Most of the shunts were behind the pilot side panel on the back wall. Quote Link to comment Share on other sites More sharing options...
gras747 Posted October 12, 2023 Author Report Share Posted October 12, 2023 I cleaned the 4 shunt connections and flew for 2 hours with no problems then the GREMLINS came back to haunt. Both ammeter leads to the shunt have fuse holders that I cleaned the fuses also. Why are these neccesary ? I also cleaned all the stab connectors on the terminal block on the firewall behind the RH panel. I don't have a schematic (any help there???) but do I need to start at the battery negative terminal on the engine side of the firewall and clean and treat every connection? Yikes! Quote Link to comment Share on other sites More sharing options...
gras747 Posted October 12, 2023 Author Report Share Posted October 12, 2023 In re-reading my post I think I know that these fuses are to protect the Dynon ammeter in case there was some kind of surge of current from the shunt. IE a failed shunt Quote Link to comment Share on other sites More sharing options...
FredG Posted October 13, 2023 Report Share Posted October 13, 2023 Those fuses prevent the ammeter sense wires from burning up if one were to short to ground (should the insulation abrade) or if either wire came loose from the plug into the Dynon and shorted to ground. There is no other protection for them. Quote Link to comment Share on other sites More sharing options...
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