I checked my mc18's RC servo as it appear to be not functioning properly. Hooked up a battery to the W/R and W/BL wires and nothing. I guess that means the servo is dead.

I am wondering if I can use a donor mc21, or 28 servo as a replacement or is there a way to fix mine. Hooked up the battery to the W and W/BL wires and the motor spins fine. Seems like the potentiometer is dead. Resistance is 0-2 ohms only.

Suggestions?

Haven't measured an MC18 in an age, but I'm pretty sure that the pot is 5ohms just like the MC21, MC28 and NSR150.

For your info, the TPS is also a 5ohm pot.

Wiring in a later model servo should be a breeze. Just check the wire colours carefully and match them up. They all do the same thing.

Maybe also run the engine with the RC valve actuation cables disconnected just to make sure that the servo is doping what it should.

I've saved a couple of TPS pots before by throwing them in the ultrasonic cleaner, but never done an RC servo pot. Never needed to.

Cheers,

Matt.