I can confirm that I have a similar problem (or I'm hoping I HAD!)
For some time I have had an intermittent similar problem. The trim will
always go nose up no problem but should I go a LED bar too far it won't
reverse until I take it full nose up (huge control stick forces) then it
usually but sometimes only after about a minute will return. I suspected
the servo motor which since my Kit No. is 337 I guess will be the old
one. I had lots of written exchanges with the Ray Allen Co. resulting in
my sending it back for check over since they had concluded that an "end
or limiter switch wasn't allowing the reversing of the motor. I
returned it to them unfortunately they had a bad day when they received
it and didn't link my motor with my communications but checked it out
and found no fault.
I refitted it and when plugging my connectors at the panel back together
I discovered an internally broken or badly crimped wire.
I remade the wire connection and "hey presto". After two years it seemed
However since then the problem has again returned and I have not been
able to get it to repeat on demand. The last time I flew I did my
pre-flight checks and I trimmed up a couple of LED bars and it wouldn't
return, pulled off the ramp and sat operating both the control on the
stick and the one on the panel. After about 10 minutes of multiple
switching it came back to life. I flew my mission ensuring not to trim
too far nose up, and on the return leg repeatedly trimmed nose up then
nose down without problem.
I have again checked all my connectors and stood for an hour trying to
reproduce the problem to no avail. I'm wondering if it is the relay
If you manage to isolate your problem would you be good enough to let me
Bob Harrison G-PTAG
I posted a similar message on the Aeroelectric board. I am having
intermittent problems with my electric trim. Sometimes when I need to
slow and trim the aircraft for landing the trim motor won't actuate. I
initially suspected the down trim button, but once I had it not wanting
to respond to an "UP" button press as well.
I have wriggled wires, plugs and un plugged terminations and driven the
servo to the end stops but I haven't been able to duplicate the problem
on the ground. I am starting to suspect the servo and I am thinking it
might be having trouble reversing direction with air loads.
I'd be interested in anyone's ideas for trouble shooting. I have a 4 way
trim switch with a Ray Allen relay deck driving an older MAC servo unit.
One last question, can any one tell me the new part number for the servo