M20J Flaps Circuit Breaker Popped

[DPM20J]

I flew back from Wagner, SD in moderate to occasional severe (for me) turbulence yesterday.  I landed with full flaps and retracted flaps at landing.  When I was parking plane, noticed flaps still down.  Figuring I forgot to retract, I turned on Master and tried raising.  Nothing.  I looked and discovered Flaps circuit breaker popped.  Reset breaker with Master off and it stayed in.  As soon as Master turned on, it popped.  I also tried it this morning, same result.  No previous flap issues.

Where do I start?  My plane is parked outside in Tower, MN (12D).  It's supposed to be relatively warm Friday/Saturday.  It would be nice to get it figured out, if possible.

Any help appreciated!

[Oscar Avalle]

I had a similar problem with my circuit breaker panel. Turbulence had moved a a lose connection in the panel and it touched another cable and that made the beaker pop


Sent from my iPhone using Tapatalk Pro

[AnAngryGoose]

Start by disconnect the flap motors, one at a time, and see if it pops. The motor could be shorted internally causing it to pop.

If that isn't it, try physically chasing the wire leaving the breaker to any point where it may be chafing and shorting to ground. Also check and be sure all connections on breakers are tight.

I'll try to find a diagram to help more.

Edited October 18, 2022 by AnAngryGoose

[larryb]

There is only one flap motor.

I had the same symptoms, popping the CB when trying to lower flaps. For me the problem was the relays. There are two relays on the flap control circuit board located above the belly panel. There are also some limit switches that control the circuit. There are several versions depending on year. A person skilled in electronics could replace the relays as a component level repair. The boards from Mooney are very expensive if they are even available. There are a number of threads on MS discussing this issue.

[DPM20J]

When I was briefly diagnosing, I believe the breaker pops when the Master is turned on, without the flap switch engaged.  Wouldn't that point to a hot wire in the flap circuit grounding issue rather than the actual flap motor?

[carusoam]

The wiring diagrams are in the service manual…

The service manual is free from your favorite MSC… electronic copies…

Some service manuals are available in the download section…

Flap relay switches get plenty of discussion… usually they stop working properly after a couple of thousand hours and they are expensive to replace… they also behave like limit switches when working properly…

I don’t recall any common issues causing the flap CB to open… 

There have been a few CBs opened… just for having stuff fall across wire connections behind the panel…

Good luck with the chase!

 

PP thoughts only, not a mechanic…

Best regards,

-a-

[A64Pilot]

On 10/18/2022 at 7:45 PM, DPM20J said:

When I was briefly diagnosing, I believe the breaker pops when the Master is turned on, without the flap switch engaged.  Wouldn't that point to a hot wire in the flap circuit grounding issue rather than the actual flap motor?

Or a stuck relay maybe?