Rotorhead Posted April 30, 2022 Report Share Posted April 30, 2022 (edited) Hey all, When flying around, it seems as though the cluster gauges are not reading correctly. Only saying so since when I press on the panel, all the instruments change the reading and read more closely to the JPI 730 onboard. Tried looking for any loose grounds but couldn't find a smoking bullet yet. The picture is behind the gauge cluster and just want to ensure it isn't missing a ground that some others may have hooked up. There are 2 ground straps on each end attached to the aluminum top panel though. Let me know what your thoughts are. Edited April 30, 2022 by Rotorhead 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 30, 2022 Report Share Posted April 30, 2022 Cluster gauge gets grounded to the panel as well… Have checked its connection? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
PT20J Posted April 30, 2022 Report Share Posted April 30, 2022 If it is grounded to the panel, make sure that the panel is grounded to the airframe. There should be a little copper strap that bridges at least one of the panel LORD shock mounts. 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 1, 2022 Report Share Posted May 1, 2022 +1 for checking ground straps…. Know that some Mooney panels use rubber mounts that can often inhibit grounding… -a- Quote Link to comment Share on other sites More sharing options...
Rotorhead Posted August 1, 2022 Author Report Share Posted August 1, 2022 I've tried temporarily grounding the whole cluster gauge unit directly to the grounding panel with no real difference. I used one of the posts as circled and thought that would be a secure and solid grounding point. Am I missing something here? Quote Link to comment Share on other sites More sharing options...
201Mooniac Posted August 1, 2022 Report Share Posted August 1, 2022 If it is like on my 1980 M20J, those aren't grounding posts, they are terminals for lighting. If you look under the tab you will see a hole for a light bulb for each of the gauges. If you install light bulbs, you can daisy chain wire those terminals to provide power for the bulbs. 2 Quote Link to comment Share on other sites More sharing options...
Rotorhead Posted August 1, 2022 Author Report Share Posted August 1, 2022 18 minutes ago, 201Mooniac said: If it is like on my 1980 M20J, those aren't grounding posts, they are terminals for lighting. If you look under the tab you will see a hole for a light bulb for each of the gauges. If you install light bulbs, you can daisy chain wire those terminals to provide power for the bulbs. Well be damn I had no idea. May try out the lights once this ground issue is figured out. Appreciate the insight! Quote Link to comment Share on other sites More sharing options...
carusoam Posted August 1, 2022 Report Share Posted August 1, 2022 Connecting wires randomly to things that look familiar may not work out very well…. This is why we have actual mechanics and avionics people… You might want to use a volt meter and continuity tester prior to seeing sparks fly… If you haven’t found the ground strap yet… that could be a hint you are chasing the right thing… But, embarking on an electrical solution without the proper tools can lead to crummy results… PP thoughts only, not an electrician… Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Rotorhead Posted August 1, 2022 Author Report Share Posted August 1, 2022 (edited) I tested for continuity and ground prior to "randomly" putting a test wire on to that post. New Lord mounts that connect to the ground strap are on back order unfortunately. Edited August 1, 2022 by Rotorhead 1 Quote Link to comment Share on other sites More sharing options...
chriscalandro Posted August 1, 2022 Report Share Posted August 1, 2022 That doesn’t sound like a thing a ground would do. it sounds like a thing pressing on a gauge and effecting it’s inner springs and mechanisms would do. Quote Link to comment Share on other sites More sharing options...
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