165: Sunday 17th October 2010

Today I was dropping off a friend of my daughter, then I lost control of the throttle. I was getting no drive until I nailed the throttle pedal, then I got full throttle. It was like having a throttle switch with full on and full off as the only states. I put him in 3rd gear to smooth the drive out a bit and got home. I checked the throttle using the tester function on the controller with the gearbox in neutral and I could see no change until about 80% when the motor fired up. So the throttle potentiometer was playing up. This a heavy duty sealed type potentiometer, so there was nothing I could do but change it. I had some 10k pots in my electronics spares, but the shaft was 4mm compared to 8mm of the original, so I used some brass tubing to increase the shaft size. I fitted the lever back and put it all on the car, then I had the controller learn the new throttle pot extremes. When I tried it again, control was back to normal so I had nice control across the range of the pedal. Thankfully this happened in the early afternoon, so I had a good amount of time to solve the problem. So it all seems o.k. now and I have a bag full of these potentiometers in my garage in case it goes again. I think this was my first breakdown where something has actually gone wrong and needed repair other than just charging up. I am not counting my original batteries as they were second hand to start with and only a temporary solution. When they did give in, it was nothing less than expected and planned for.