Flipped my erg now PM5 doesn't register flywheel motion

[mwalsh]

Flipped my erg over to adjust the shock cords, being super careful of the mounted PM5. Flipped it back over and now the PM5 doesn't appear to be getting anything from the flywheel sensor.

So let's assume that, coincidentally and annoyingly, the sensor went bad...how can I check for that? I already hooked a speaker to wire that goes into the PM5 and didn't hear anything - I thought I read somewhere that I would. What is the voltage that's supposed to be produced as the magnets in the flywheel pass it?

[mwalsh]

Figured it out - cable broke internally. Cut the center part out, joined the two end bits together, and was able to get a good resistance measurement.

Going to try and repair with a section of old audio cable for now, and have ordered a new sensor from C2.

[kris-o]

Bit weird that you were able to break a cable this way...

[mwalsh]

Well I fitted the PM5 myself, but the cable was still routed the way (I assume) it was originally for the PM2, which in this instance was underneath and around the bolt hole for attaching the PM bracket to the chain guide.

I folded the PM5 back on it's bracket so it was sitting beside the flywheel back cover, just as I'd seen in the literature, and I guess that was just too much strain on that particular section of cable.

Although I've left a bit more slack in the repaired cable I'm going to go the extra mile next time - detach the cable from the PM entirely and pull it away from the PM bracket so that it's left behind when I fold the bracket back. Since I'm so paranoid about damaging my PM5, I'll actually probably remove it from the bracket too.

Lesson learned, I guess.

BTW, the resistance measurement you'd expect to get from a good sensor is supposedly around 105 Ohms give or take either way. Mine was reading 112 Ohms when tested as good and infinite to maybe 60 Ohms when I was squeezing and massaging the cable with the bad section still in place.