Thankyou very much. "I've often wondered why this issue of the LED indicator leading to a failure to excite the alternator seems to be something of a recent phenomenon - I can't find many references to anything similar from the time when these cars would have been newer. On my car, the LED only feeds about 4mA into the excitation wire, but it seems to get away with it. I've only really had a chance to look at this on my own car and others which have been experiencing the problem, but I did wonder if on the K-Series era cars there may have been a resistor like this built into the tacho where it cannot be seen; and as they do run hot, I wondered if they were actually burning out eventually, leaving just the LED current and marginal startup performance." Isn't it interesting? Even if we narrow down the Sevens at risk to those with LED warning lights AND combined circuits for the warning light and excitation there might be something else, but I suspect that it's variation between alternators. These observations are going to make it much quicker to pinpoint problems. Jonathan