RV-12, S/N 120147 with D-180, 360 hours, flying 5 years:
Depression of trim switch up or down does not actuate the servo and does not yield a voltage signal on either the white or white/red wires at the spade connectors at the servo. A continuity check on these individual wires from the spade connectors to pins 31 & 32 at the D-sub (WH-00046, Fuselage Wiring Harness) show zero resistance (i.e., continuity on each wire). Turned trim potentiometer slightly counter clockwise and no effect. I think that the next step is to find out what signal is coming out of the ?control panel?. I?m not sure how or if I want to tackle that. What do I check next or whom do I contact?
More history & troubleshooting details:
Trim has worked flawlessly for years until recently when during pre-take-off check the trim down would not work. Then, tried it again and it did work. Thought that perhaps I had not depressed the switch all the way initially. I doubt that this is associated, but for added info.: Prior to take-off charging system appeared normal. During the flight, the amps were more in the negative than the positive and the voltage was dropping gradually. Continued to monitor the volts and amps for say approx. 10 mins. Then, the amps. began going positive and the voltage increased. Performed the forum prescribed voltage regulator diagnosis and found nothing conclusive. But, decided to replace the voltage regulator anyway. Immediately after the v.r. replacement, and during pre-take-off check found that the trim was not working. Troubleshooting included checking the battery voltage after its overnight rest: 12.6v. Tried the trim while charging the battery: No effect on trim. Bypassed everything with (2) separate wires hooked directly to the plane?s battery and to the spade connectors white and white/red wires at the servo and the servo does work and the indicator appears to be indicating the correct position.
During troubleshooting, found when trim switch is pressed, there?s 5v to ground at one or more of wires that are not the white only or white/red wires. I didn?t take note exactly the colors of these wires since we?re supposed to get the voltage on the white and white/red wires (power wires) and we?re not getting voltage there. Also, I was surprised to find continuity between the wht./grn., wht./blu., wht./org. wires pins 4, 22, & 25 respectively. I don?t know what signal or cross connection is to be expected on the non-power wires. I only mention my findings if this might be a clue as to what?s going on.
Side note: Tried actuating the servo with a 9v transistor radio battery and it didn?t actuate the servo.
Again, what do I do next or who do I contact for assistance?
Depression of trim switch up or down does not actuate the servo and does not yield a voltage signal on either the white or white/red wires at the spade connectors at the servo. A continuity check on these individual wires from the spade connectors to pins 31 & 32 at the D-sub (WH-00046, Fuselage Wiring Harness) show zero resistance (i.e., continuity on each wire). Turned trim potentiometer slightly counter clockwise and no effect. I think that the next step is to find out what signal is coming out of the ?control panel?. I?m not sure how or if I want to tackle that. What do I check next or whom do I contact?
More history & troubleshooting details:
Trim has worked flawlessly for years until recently when during pre-take-off check the trim down would not work. Then, tried it again and it did work. Thought that perhaps I had not depressed the switch all the way initially. I doubt that this is associated, but for added info.: Prior to take-off charging system appeared normal. During the flight, the amps were more in the negative than the positive and the voltage was dropping gradually. Continued to monitor the volts and amps for say approx. 10 mins. Then, the amps. began going positive and the voltage increased. Performed the forum prescribed voltage regulator diagnosis and found nothing conclusive. But, decided to replace the voltage regulator anyway. Immediately after the v.r. replacement, and during pre-take-off check found that the trim was not working. Troubleshooting included checking the battery voltage after its overnight rest: 12.6v. Tried the trim while charging the battery: No effect on trim. Bypassed everything with (2) separate wires hooked directly to the plane?s battery and to the spade connectors white and white/red wires at the servo and the servo does work and the indicator appears to be indicating the correct position.
During troubleshooting, found when trim switch is pressed, there?s 5v to ground at one or more of wires that are not the white only or white/red wires. I didn?t take note exactly the colors of these wires since we?re supposed to get the voltage on the white and white/red wires (power wires) and we?re not getting voltage there. Also, I was surprised to find continuity between the wht./grn., wht./blu., wht./org. wires pins 4, 22, & 25 respectively. I don?t know what signal or cross connection is to be expected on the non-power wires. I only mention my findings if this might be a clue as to what?s going on.
Side note: Tried actuating the servo with a 9v transistor radio battery and it didn?t actuate the servo.
Again, what do I do next or who do I contact for assistance?