OK... 80W @12V means 80/12=6.66A, so say 20mA (0.02A) shouldn't be a problem to tap off...

A current no higher than 20mA @ 12V means the coil resistance must not be below 12/0.02=600 Ohm. I definately recall seeing 12V relays with coils in the 600 to 800 Ohm range...

/Michael