Red light stays on aftr gear goes up and locks

[scott]

Hello,

I see a similar post on this site is up on this same problem.  I have a PA31-350 1974 and the red gear light stays on after the the gear is raised and locked.  But the main gear doors stay down and don't allow the the  gear up cycle to complete  The extension (gear down) cycle of the gear works flawlessly.  Similar problem to the other thread but adding Hydro fluid did not help. 

The gear up limit switches appear to mechanically work correctly.  We also tried to check the continuity of the switches and think they are working correctly (1CH21-4 micro switches).  Since there are 6 wires coming out and the schematic shows which wires match it appears that the electrical portion on the insides of the switched are good but were not sure because we cant find any specifications on what the wires should ring out to.  We bought extra switches to compare; still sort of inconclusive.  The wiring all "looks" intact via visual inspection.  We have been trouble shooting this issue for a couple days with no luck.

My A&P is admittedly not an expert on Navajo landing gear and I don't know of any locally (St. Louis Missouri (1H0)) that can help.

My question is, is there a systematic procedure to follow to trouble shoot the problem or do you know someone I can contact? 

Any ideas or comments are welcome.

Scott

[scott]

Think the problem is solved. After quite a bit of trouble shooting, we found a bad solenoid switch on the power pack. Ordered a new one and will install and see what happens.

[klausnw]

I wish there was a simple common gear door troubleshooting procedure. Many times the wheel/door sequence would go wrong and the plane would be seen with the wheel outside the wheel well. The best fix to your problem is discussed here:

pa31typeclub.proboards.com/thread/19/arc-inboard-mlg-door-removal

[scott]

Thank you sir. I will read it now.

[ronnie27478]

Jul 24, 2019 14:03:41 GMT -9 scott said:

Think the problem is solved. After quite a bit of trouble shooting, we found a bad solenoid switch on the power pack. Ordered a new one and will install and see what happens.

I just had a similar issue with my Navajo.  During run-up, the gear handle would not move from the down position back to the center (neutral) position as per the checklist procedure.  After shutdown, the gear doors were down and an observer told me they dropped down as soon as I started the first engine.  I found the Landing Gear Safety circuit breaker popped.  After looking at maintenance manual a bit, it appears that maybe the power pack solenoid is bad.  I disconnected the electrical cable from the power pack and the circuit breaker no longer popped when the master was turned on.  I reattached the electrical connector to the power pack and the circuit breaker popped.  Other than the micro switch in the power pack, I can't see any other electrical components in the power pack.

Where did you find a solenoid part number?
    UPDATE:  I found this in the IPC.
    My Power Pack Assembly
is the Wiebel 2135-1
(WTC22135-1), Piper PN 481 171

    This uses Solenoid assembly
 Wiebel Tool Co PN 2135015-1
, Piper PN 762 310

     I've not contacted Piper yet, but so far I have not been able to find a source for just the solenoid, only the complete power pack.  Any suggestions?

Where you able to replace the solenoid without removing the power pack from the airplane?
Any idea as to the proper resistance reading for a good solenoid?

If a field replacement of the solenoid was not possible, who did you use to repair the power pack?
    UPDATE: Looks like PowerPacksPlus.com is a re-builder of these.

Piper Lists the Ozone OAS2930-7, Piper PN 481 166  or 757 457 as alternate parts.  Has anyone switched from the Wiebel unit to the Ozone unit?  Just wondering if there are any issues such a hydraulic lines which have to be moved or modified.

Your help is greatly appreciated. 

Ronnie

[ronnie27478]

UPDATE: There is a 35uF 50V electrolytic capacitor across the solenoid.

My Power Pack Assembly is the Wiebel 2135-1, Piper PN 481 171.


The capacitor was shorted. Replacing the capacitor solved the problem.

Ronnie

[AVAIR]

Hi,
Having same problem but only in flight...Gear cycles perfectly on jacks and fails to close main gear doors in flight...
Any ideas?