KAP150 Lateral problem

[teethdoc]

KAP150 in an M20J MSE, passes test, will hold Alt but none of the lateral functions (HDG, NAV). The light comes on, but if you twist the HDG bug, nothing.  The airplane does not respond.  Sometimes it works, sometimes it doesn’t.

[LANCECASPER]

49 minutes ago, teethdoc said:

KAP150 in an M20J MSE, passes test, will hold Alt but none of the lateral functions (HDG, NAV). The light comes on, but if you twist the HDG bug, nothing.  The airplane does not respond.  Sometimes it works, sometimes it doesn’t.

@Jake@BevanAviation knows these autopilots well.

[Jake@BevanAviation]

Possible issue in the KC191 flight computer or roll servo.  If you can gain access to the roll servo and disconnect it from the ship you could monitor to drive command across pins D and L at the roll servo connector to the ship.  With a DC volt meter the AI spooled/level, the heading/course pointer under the lubber line, and the autopilot engaged in heading and AP engage modes you should see close to 0vdc.  Moving the heading bug left and right of the lubber line should create a increasing DC drive voltage.  Going one direction will be positive voltage and the other direction would be negative voltage.  This will check the drive voltage from the computer.  If you check Pins E to C this is the solenoid engage voltage. It will go positive and stay positive when the flight computer is engaged.

It would also be helpful if you could find out what servo version you have.  Some Mooney's have the KS-17X series of servos, other have the more common KS-27X series.  Both servo assemblies function exactly the same but the KS-17X have different parts and some a getting hard to find.    

[Fly Boomer]

2 hours ago, Jake@BevanAviation said:

It would also be helpful if you could find out what servo version you have.  Some Mooney's have the KS-17X series of servos, other have the more common KS-27X series.  Both servo assemblies function exactly the same but the KS-17X have different parts and some a getting hard to find. 

As an example, my trim servo is a KS-179 065-0052-14.  I see one at BAS including mounting bracket.  If it came out of something other than a Mooney, can my mechanic remove the bracket it's attached to, and install in my Mooney using my old bracket? 

[Jake@BevanAviation]

3 hours ago, Fly Boomer said:

As an example, my trim servo is a KS-179 065-0052-14.  I see one at BAS including mounting bracket.  If it came out of something other than a Mooney, can my mechanic remove the bracket it's attached to, and install in my Mooney using my old bracket? 

Yes, you would want to use the bracket that is in your aircraft for servo mounting.  Just be sure that the servo dash number matches the one you have.  Some servos are voltage specific 14 or 28.

[Pinecone]

FYI I have the KAP-150 parts from my plane.  Computer and servos. Make me an offer.