65C_flier

Thanks @N201MKTurbo Both the radio and instrument dimmer knobs/circuits still work, except they no longer dim the glareshield lights. Do the glareshield lights have their own transistor? Do you know if it is located in the dimmer assembly?

Has anyone seen an issue where the glareshield lights don't dim or turn off? The other radio and instrument lights dim, but glareshield lights are on full bright regardless of dimmer position. 78 J. Glareshield lights used to work fine (dim with instrument dimmer) and this just started after a night flight.

Anyone know why the glareshield lights would get stuck on (78J)? I think the instrumemt dimmer that controls my glareshield lights has been on the way out for a while. On a recent night flight all panel lights were working (and dimming) properly, except the glareshield lights which were very dim. During taxi after landing the glareshield lights came on full bright and now they wont turn off even with both dimmers in the off position. Oddly, some of the other lights (flap indicator backlight) still dim. Internal failure of the dimmer switch? I will probably change the glareshield lights for an LED strip and replace the dimmer with a PWM dimmer eventually, but I'd like to do a quick fix on the existing lights if possible.

Good idea. I'll go and have a look on the weekend. Now I'm off to the schematics to find where the shunt lives.

It could be a natural engine freq, but it does it engine off as well. Very interested in hearing whether your ammeter needle has any slight oscillation before engine start. Regarding your issue I wouldn't have thought there would be a lot of current through the master or field wire? Isn't it just passing a voltage drop signal to the alternator to tell it to crank up amps to power the system demand?

My ammeter oscillates slightly (1/2 needle width or less) even with engine off and all systems (including strobes) off. Needle jumps wildly when systems are turned on (with and without engine running) before quickly settling to the slight oscillation. I have confirmed no voltage drop up to VR (engine off). I swapped VRs from my old Electrodelta to a Zeftronics and it still does the same slight oscillation with engine off and large jumps when systems are turned on, so I am thinking that it must either be: 1. Internal corrosion of the master (given I have cleaned/ tightened all 4 connectors which seemed to clean up the JPI voltage data. JPI data used to show lots of change from 13.8 to 14.2V before I cleaned switch so hopefully this fixed it, but I dont understand why slight needle oscillation persists) 2. Normal system behaviour. 3. The ammeter itself. I have looked at the connection and it isn't corroded. A bad ammeter also wouldn't cause the alternator to kick off in flight would it? I am paying close attention as I lost the alternator 2hrs into a 4hr flight recently. After the characteristic full scale ammeter fluctuations that started 1.5hrs into the flight the voltage dropped (alternator quit) and unlike previous times this had happened it didn't come back for most of the 2hr return flight (which was long enough that the Aspen efd1000 ran out of its backup battery...) Fortunately it was day VFR, but I want to be very sure I have fixed the problem before getting back into cross country night IFR. If anyone can confirm whether slight oscillation engine off is normal it would be greatly appreciated

@FlyBoyM20J Just wondering if people still see a slight oscillation of the ammeter even when the system is working properly (engine on and off)? I have had the intermittent full scale ammeter fluctuation in flight (including some flights where the alternator quits for varying lengths of time - sometimes automatically resets, other times it didnt). I have cleaned the master switch connectors, tightened the field wire post on the alternator (was a bit loose), checked alt field cb resistance, etc. EDM830 voltage data looks cleaner now and I haven't had the wild random fluctuations in flight, but the ammeter still oscillates very slightly (1/2 needle width) even before engine start. Ammeter also jumps / oscillates a lot when systems are turned on (with and without engine running). I would expect a bit of a response when a load is applied, but the jump and oscillation seems disproportionately large (3/4 scale with some overswings) when low power systems are turned on. Is that normal or a sign that I haven't solved my problem? 78J

@M20Doc Trying to figure out what torque to use on exhaust stud nuts. MM seems to say 100-110 in.lb, but are we saying it needs to be 204 in.lb?

I generally agree; why fix it if it aint broke? My reason is that I am having fluctuating ammeter (as described in the DMax article) on a 78J, but it hasn't been fixed by cleaning the master switch contacts. We have also checked the recently overhauled Prestolite alternator (voltages / resistances across alternator and CBs are good), field wiring, earth, etc all look good. Electrodelta VR seems to be regulating properly (although could have an intermittent internal fault I guess), so we are considering replacing the master switch (in case of internal corrosion). If a split master is (or can be) approved it might be a cheaper option and have added functionality (albeit, not required functionality) Something like this https://lasar.com/switches/master-switch-688-169 vs something like this https://lasar.com/switches/rocker-switch-master-switch-circuit-breaker-880052-501

+1. Just giving this old post a bump to get people's thoughts on replacing the Mooney 2 pole single throw with a split switch. Apart from the added benefit of being able to control the alt separately, they seem a whole lot cheaper. Thanks.

The Dukes air switch on my 65C was 3203-00. It was adjustable by screwing the switch in/out (remember to loosen the grub screw). Later models had a different part number i believe.

Thanks gents.

Brad, My J has a Shadin FF tx with a bracket off of the sump similar to Skip's schematic (although mine is installed wires up). We are replacing it as part of a JPI EDM830 install and I'd like to use the firesleeve per JPI instructions, but it doesn't seem possible with that bracket. Does your install use a firesleeve?

Will do. Looking for a J diameter.

Hi all, can somebody please tell me the diameter of the control shaft (that the yoke bolts on to). I want to buy a collar for mounting my iPad, but my J is a few hours away at the moment.

The sensorcon has a replaceable battery (at least mine does).

I ran into @DanM20C at the Mooney tent at Oshkosh last week and he very helpfully calibrated my Sensorcon (by the way thanks Dan!). My CO level has always been around 10-40PPM on the ground and less than 10 in flight, but on the flight out of OSH the Sensorcon triggered the 35PPM alarm a few times (max of low 40s). I assumed it was related to the calibration until the next flight when the same thing happened, but this time my Sentry also triggered (inbuilt CO monitor that interfaces with Foreflight, but no PPM reading). I did some troubleshooting with cabin heat, cowl flaps, etc and there was no clear trend. As soon as I got home I did the trusty shop vac in the exhaust and soap water spray trick. Sure enough 2 of the ball joints have pretty good leaks. Time for some exhaust maintenance and resealing the cabin! Highly recommend carrying a CO monitor and keeping it calibrated.

@Bob_Belville I have been watching this closely as I plan to do a similar trip before Osh. Currently planning KDSM, KRAP (although I'll have a look at KCUT now) then into KWYS. We are currently thinking about going into KWYS from the north (via KBIL) and out west-to-east through the park to KCOD, depending on the wx. I'm still trying to figure out the KCOD to KMSN bit. If your trip is organized as well as you and Nancy organized the MAG clinic I might need to scrap my plans and just copy what you do! @Skates97 thanks for the pics and tips. We will plan to follow the main road as you suggest. Any other tips / advice would be very welcome.

Thanks. That is what I thought from the wiring diagram, but I just wanted to make sure. I guess I'll be installing a post light.

Hi all, Is there supposed to be in-built lighting for the gauges in the standard Garwin 6-pack engine instrument cluster on a 65C? My instrument lights have been modified with LED bezels by a previous owner, but the engine instruments have no lighting and the overhead flood lights have been removed.

I had an over voltage light coming on intermittently. After replacing the zeftronics (and not fixing the problem) we found it was a frayed field wire on the alternator.

No, hoping to get it adjusted

I had the exact same issue last week. After the IFR recert the gear wouldn't come up until 97mph (up from 85mph before recert). I also have the Dukes 3203-00 and came to the same conclusion that it was the issue. During troubleshooting it retracted at 87mph at 3000ft, but is solid at 97 during takeoff...

Hi all, I'm also looking for #106. Any PMs would be appreciated.

Now I am confused! I can not find a pilot valve anywhere in my PC system (65C with electric yoke button mod). Does the electric yoke switch with solenoid (part number 4085) replace the pneumatic pilot valve?