[davepl]

I can't tell what the impedance is from labelling (factory GM unit). Can I measure a coil trivially with a meter or does magnetism come into play and mess that up? If it were too low, could I add a 1/2W resistor? Seems not big enough to dissipate the heat offhand.

Problem is everyone I've talked assumes a NC contact on the relay. That's not how they seem to be set up. I'll pull the cover off and get a photo of the coil/contacts before we speculate more, sorry. If it does have one I was done three days ago but didn't know it...