Thanks for the reply - I have an alldata and EPC subscription, so I have checked all the usual suspects. The only thing I never verified was the harness ground - which did appear on the alldata list, but I just assumed that a ground fault would show up in other systems. i will check it tonight (or tomorrow - very cold tonight). I have been thinking of WIS software and possibly some laptop diagnosis equipment (the $50 ODBII is obviously not quite sufficient). Any suggestions?