ignition wire question first...

[Ridercam]

I rebuilt my "totaled" bike after a major altercation during rush hour on the San Francisco-Oakland Bridge. Frankly, I continuely work on this bike on my slim budget. The bugs and perceptions from that mishap may still haunt me. Idle issues have persisted. Replacing electronics and dealing with electrical issues are relitively new to me as this bike has been quite the machine to me for 25 years. Interestingly enough during a tech day a few years ago, we discovered and subsequently repaired its wiring harness which had been installed upside down from the factory. Anyway, a 29 dollar ignition control unit seem like wise step on my way as I begin to secure this loved bike from a roadside breakdown.

[Rob Frankham]

On other vehicles I have seen a bad electronic control module will fail when hot, and work again cold, but only a couple of times before total failure.

This is quite a common happening with boxers... however... it often isn't a fault at all in the sense of a failed component. The ECM used by BMW has an overheat feature. When the circuitry starts to get uncomfortably hot, it shuts down to avoid damage. This seldom happens in normal use, unless the ambient temperature is very hot. If, however, the ECM isn't attached to an efficient heat sink, it will overheat quite easily even when air temperatures are quite low. The cure is to remove the ECM module from it's heat sink, thoroughly clean the contact surfaces and apply a new coating of conductive paste before bolting them back together. The paste is easily obtainable form any electronics shop and also, these days, from many auto factors. I do winder, sometimes, how many perfectly good ECMs have been thrown away as intermittently faulty.

Rob