NicoN Posted January 1, 2019 Report Share Posted January 1, 2019 Happy New Year to all Mooniacs! My 2019 started with a definitvely homemade problem! Today, we wanted to add a wire to one of the C/B. In contradiction this porcess was more complex than the Maintenance manual told us. My compagnion opened in addition one of the big round connectors on the back of the panel. Also he looked on the group of the switches where the master is. But there was no change in the wiring of the master switch. After adding the wire to the C/B nothing works ! We simply have no electrical power. Switching the master does nothing ! There is not even the typical sound of a relay (or solenoid - what's the difference?). There seems to be on relay in the right footspace and another two in the tailcone next to the battery case. The one on top of the battery case seems to control the ground power plug. Is the one behind the master relay? I am looking for some information how to track down the problem Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted January 1, 2019 Report Share Posted January 1, 2019 You probably broke the wire going to the aux bus. Check around the AUX CB. Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted January 1, 2019 Report Share Posted January 1, 2019 THE CBs are a big PITA. I have found the easiest way to work on them is to go big. Remove the panel nuts from all the CBs. Remove the screws from the gauges. Remove the screws from the top and bottom of the panel and remove the whole panel leaving the CBs hanging. It is easier than it sounds. 1 Quote Link to comment Share on other sites More sharing options...
NicoN Posted January 1, 2019 Author Report Share Posted January 1, 2019 Thank you for thequick answer! The AUX CB seems to be reachable pretty easy with removal of the glare-shield - right? Can I measure something at typicla places? 12V on the AUX Bus CB? Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted January 1, 2019 Report Share Posted January 1, 2019 3 minutes ago, NicoN said: Thank you for thequick answer! The AUX CB seems to be reachable pretty easy with removal of the glare-shield - right? Can I measure something at typicla places? 12V on the AUX Bus CB? Yes, it should be at the top of the panel. The master switch should ground the master solenoid coil, You should measure some voltage on the master switch when it is off. If you don't, check the inline fuse in the tail at the master solenoid. Quote Link to comment Share on other sites More sharing options...
Yetti Posted January 1, 2019 Report Share Posted January 1, 2019 The solenoid on the foot well in the engine compartment is the Starter solenoid. The Master is in the radio bay down low. The one on top of the battery case is the shore power. Quote Link to comment Share on other sites More sharing options...
carusoam Posted January 1, 2019 Report Share Posted January 1, 2019 Relay, contactor, and solenoid... often used interchangeably.... even though there are some small technical differences... Often Mooneys have at least two or three relays... Master Starter Avionics (wired in reverse operation for back-up) Battery selector (two battery system) Ground power plug (safety for reverse polarization) Any others? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
NicoN Posted January 1, 2019 Author Report Share Posted January 1, 2019 Thank you for all the tips Quote Link to comment Share on other sites More sharing options...
Mcstealth Posted January 4, 2019 Report Share Posted January 4, 2019 On 1/1/2019 at 4:37 PM, NicoN said: Thank you for all the tips Did you find it? The issue? Quote Link to comment Share on other sites More sharing options...
Yetti Posted January 4, 2019 Report Share Posted January 4, 2019 On 1/1/2019 at 2:20 PM, carusoam said: Relay, contactor, and solenoid... often used interchangeably.... even though there are some small technical differences... Often Mooneys have at least two or three relays... Master Starter Avionics (wired in reverse operation for back-up) Battery selector (two battery system) Ground power plug (safety for reverse polarization) Any others? Best regards, -a- Those are the big solenoids on the B+ side of things. There is a relay or 2 for the landing gear, One for the landing light next to the avionics. On the older radios there is a relay for the transmit side. 1 Quote Link to comment Share on other sites More sharing options...
NicoN Posted January 4, 2019 Author Report Share Posted January 4, 2019 @Mcstealth: Not yet. Too much to do at work and low temperature in the hangar. My greatest suspect is, that the MAster witch has some issue. We do not hear any sound from a clicking relay as we normally do. So, I think that my companion damaged something on the MASTER SW wiring. Yesterday I received a large format printing of the wiring scheme and I am studying it now. The printing qualitty i s not the best. AFAIK now, the MASTER SW has the function of connecting GND to a wire which leads to the coil of the master relay. The other side of the coil is permanently "hot" wired. Therefore grounding this wire should energize the master relay which does not happen at the moment. And I am not sure what the other two wires comoing from master do: One goes to the Voltage regulator, the other seems to go to Alternator, but on the Alternator side of the C/B. And in which position ? I will start another discussion on the wire naming system 1 Quote Link to comment Share on other sites More sharing options...
skykrawler Posted January 7, 2019 Report Share Posted January 7, 2019 Today, we wanted to add a wire to one of the C/B. My compagnion opened in addition one of the big round connectors on the back of the panel. You didn't say which circuit breaker you connected to and where the wire went. The cannon plug that was taken loose is likely to be the problem. Make sure it was re-connected correctly and completely screwed down. The short wires from the master switch go to a dedicated cannon plug - if that was disconnected and not reconnected you will have this problem. The wires on the master relay side of the master switch can be connected with a jumper and the master relay should come on. If not then it is NOT the master switch. Quote Link to comment Share on other sites More sharing options...
thinwing Posted January 7, 2019 Report Share Posted January 7, 2019 On 1/1/2019 at 11:31 AM, N201MKTurbo said: THE CBs are a big PITA. I have found the easiest way to work on them is to go big. Remove the panel nuts from all the CBs. Remove the screws from the gauges. Remove the screws from the top and bottom of the panel and remove the whole panel leaving the CBs hanging. It is easier than it sounds. This is very good advice...it sounds drastic but same time in the long run Quote Link to comment Share on other sites More sharing options...
NicoN Posted January 10, 2019 Author Report Share Posted January 10, 2019 Okay, power is back again. Studying the wire diagram turned out that it must have something to do with the master Switch. And that was the reason. Simply the wire to GND was missing. Re-connected it and anything is fine. 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted January 10, 2019 Report Share Posted January 10, 2019 Great follow up, NicoN... Inadequate grounds appear in odd places every now and then... That’s a big one! Thanks again for giving the update. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
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