dwanzor Posted January 29 Report Posted January 29 Recently took my new to me J model into Bevan Avionics in Wichita, KS for a transponder upgrade and asked them to troubleshoot a minor autopilot issue. Then ended up swapping my KAP computer. That fixed the original issue, however, a new issue has popped up which they have traced back to the manual electric trim switch on the yoke. Some malfunction within this switch is causing the autopilot to disconnect in flight at different intervals. They would like to replace this switch. A new part from Honeywell is $3k+ and is not available until at least October 2025. I see a couple on Ebay for around $300, but before rolling the dice on an Ebay part, I thought I would check here to see if anyone had one due to a recent autopilot upgrade. My understanding is that this trim switch will usually get replaced during an autopilot upgrade. I have the KAP 150 autopilot, but I think the Bendix King trim switch could be somewhat more universal than that. It is a split switch, left side is smaller. If anyone has one, or can point me to a good source, I would appreciate it. Quote
mike_elliott Posted January 29 Report Posted January 29 I have one from a J that was pulled when AP was changed out a number of years ago. I also have the elusive vaccum switch for the KI256. DM me if interested Edit, just checked it with a multimeter, works ok. Quote
IvanP Posted January 29 Report Posted January 29 If you cannot find replacement for reasonable price, the switch can be rebuilt. There are 3 microswitches tied together in the contraption. These can be sourced from Mouser and other places relatively cheap. The wiring is somewhat confusing, but with a bit of patience and some soldering skill, you can do it yourself. I did it couple of years ago, but cannot recall the price of the individual switches. At that time, new switch was listed at Textron for about $1,200 if I recall correctly. The images are of switch installed in Bravo with KFC 150 A/P, but I believe that the yoke trim switch is identical to that used by KAP. 3 Quote
carusoam Posted January 29 Report Posted January 29 6 hours ago, dwanzor said: Recently took my new to me J model into Bevan Avionics in Wichita, KS for a transponder upgrade and asked them to troubleshoot a minor autopilot issue. Then ended up swapping my KAP computer. That fixed the original issue, however, a new issue has popped up which they have traced back to the manual electric trim switch on the yoke. Some malfunction within this switch is causing the autopilot to disconnect in flight at different intervals. They would like to replace this switch. A new part from Honeywell is $3k+ and is not available until at least October 2025. I see a couple on Ebay for around $300, but before rolling the dice on an Ebay part, I thought I would check here to see if anyone had one due to a recent autopilot upgrade. My understanding is that this trim switch will usually get replaced during an autopilot upgrade. I have the KAP 150 autopilot, but I think the Bendix King trim switch could be somewhat more universal than that. It is a split switch, left side is smaller. If anyone has one, or can point me to a good source, I would appreciate it. good news… find the threads regarding the microswitches that get actuated by the physical switch… swapping out the microswitches is a much lower cost. PP thoughts only, from an ancient memory… hoping this memory is still intact. best regards, -a- 1 Quote
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