168: Wednesday 27th October 2010

Another one bites the dust. I broke down again today, I lost throttle control completely. The controller programmer box was indicating the accelerator voltage fault. Double disaster, my mobile phone battery had gone flat and I put it on charge through my USB port at work, and left it there. So here I was half way up a busy hill, hazard lights on, no drive and no phone. As all the angry drivers overtook me, I gradually backed up to a side turning and with a bit of a run up (backwards) I managed to go round the corner and get parked rather well in one move. I think it was more luck than judgement. I locked up the Probatron and went off to the nearby shops to find a payphone. Fortunately my wife had just come in and answered the phone. I got her to bring some 10mm spanners so I could remove the throttle and take it home for repair. She stayed with sparky while I went home and changed the pot. About an hour after the first phone call I was back on the road again on the way home. I am having a run of bad luck with potentiometers. However, I have found that the original pot that was too high for my controller at 20k ohms had a 10k resistor in parallel to bring it down to below 10k. Closer examination found that when this started playing up it was only the 10k resistor on the pot that kept it going, other wise it would have failed just like this one. This leads me to a quick repair that I can do so I don't get stranded in future. I shall keep a 10k resistor in the car and if my throttle fails again, then can links this across the input so the voltage can be detected even if it is wrong, it may be jerky, but it will get me home and the throttle switch safety override will prevent any run away as drive is removed when I lift off the pedal (and hence the micro switch). It's not perfect, but until I find a better throttle potentiometer it will get me home. I did find one on eBay that looks exactly like the original, but I can get it as a 10k linear pot, cool.

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