That is interesting and sounds kind of new.  I struggled with this situation in my 250 for a few years until I finally replaced the conduits but your situation as described has a new wrinkle.

Generally, high friction on the way down causes the gear motor to slow down, which causes the breaker to heat up, and if it takes too long it will pop the breaker stopping the gear.

What you describe is it just not even twitching or trying to come down. 

It worked fine on the gear swing, and you didn't need to reset the breaker?

William,

Correct.  It worked fine on gear swing but once I got up in the air, nothing.

I ran through some debugging while letting the autopilot fly it.  

Pulled and reset the breaker, etc.  Got slow to lower aerodynamic load, nothing.

No indication on the amp meter(digital) that the motor is even trying to run.  

No change of light to transition.  Nothing happens when putting the switch in the down position.

I have fairly new conduits (replaced within the last 200 hrs.).  And the gear was working fine until I had a hard landing that compressed the front gear enough that forced me to replace seals.  (Bad day, don't ask)

I'm thinking it is a down limit switch that may be stuck closed not allowing the motor to run.  But that is just a guess from doing some reading and looking at systems.  

Yes, I think you are on the right track.  From that description it does sound like the squat switch / wiring is failing in some manner.  Those are in a SWAMP spot and it is very plausible.   I'd check the wiring in that location first as that is more likely to fail.

However, the squat switch is there to prevent the gear from going up.  Generally, the system is set up to allow the gear to go down if something fails open.  Well, this is interesting and I am off to go look at schematics!

Matt Kurke at ComancheGear has some very nice kits if you decide to replace the switch and harness wiring.  If you do decide to replace one of them go ahead and replace all of them.  If one went the others are not far behind.

What is the serial number of the aircraft?  There are three wiring diagrams and it might be relevant?

http://comanchegear.com/wiring%20diagrams.php

@williamh, 

Mine is 24-2242.

Thanks for the info.

I've had variations of problems on landing gear. The conduit replacement is germane since worn / gripping conduits drag on the cable and cause resistance, causing the breaker to pop.

On my P30, 30-588, I gradually developed a problem which was the devil to diagnose, of my gear not going up. It's a simple system, but trial and error really with intermittent problems. I did replace the squat switch, but the problem continued, and I eventually replaced the landing gear switch, and this seems to have solved the problem. 

William's analysis is really helpful, and while your issue could be the squat switch, it might also be the gear switch. 

Your mention of getting the up light and down light is helpful, but the display of these lights is merely an indication that the squat switches have been depressed. Your issue is one of continuity around the switches, so I would encourage you (or your mechanic) to get a voltmeter and check either side of the squat switch and the appropriate wires on the gear switch. You aren't popping the breaker so it isn't a hardware problem, so it's most likely a switch, but determining which one is simple enough if you can get to the poles and get a wire on there that you connect to a meter.

Pat

So, your serial number matches figure 9-85.  From that it would appear that the safety switch does affect the gear going up or down (I would not have done that if it was my design but Mr Piper was not familiar with FMEA.) 

Therefore, if it was failed in the open position on the way down, it would only affect the gear it or the wiring was subject to a wind-storm in a flying airplane, which could be the case as you state it works normally on a gear swing.  It should also affect the gear going up but this is probably one of those escalating reliability things.  It will only fail sometimes - at first.

The gear limit switches all have to be open before the gear switch loses power.  So if the gear is headed down you would need three identical failures in three different places, all in the same subtle only-in-flight manner.  I think you can discount the gear limit switches.  You also mentioned that the gear lights work properly and they go through the gear limit switches so again those are likely ok.

The motor arm switch isn't a factor as it is not in the circuit when the gear switch is selected down.

And lastly, the gear selector switch could also be an issue - but it works on jacks and the switch isn't being thumped around in the wind in flight either, so that is unlikely.

I'd focus on the squat switch and its associated wiring.  It doesn't affect the lights and it is the only single point of failure that affects the gear coming down that is out in the SWAMP.

Again, though, if that wiring and switch is in bad shape:  just replace all of them.  It is only about one AMU for the lot and the peace of mind is well worth it.  Especially if you went to the trouble of replacing the conduits a few years ago.

As a post-script - you could also check the ground on the motor solenoid.  Almost all "haunted" electric systems I have ever dealt with involved a bad ground connection somewhere.  There is also one on the selector switch but it is unpleasant to get at and I would only go back there as a last resort.

William,

Wow, great analysis.

My mechanic, who is also the previous owner, and I went up to the airport where the plane is currently and got it ready to ferry back to our home airport.  Fixed gear version!  Gear locked down.  Once we get her home and up on jacks, we will start diagnosing the problem.  Your write-up will give us a place to start.  

Thank you so much.