>>28510742
These are probably most common. Run 12v thru 86 and 85 and test for volts, then test at 87 and 30 for continuity. Sometimes the armature fucks up.. I use a regulated 12v supply but you can do real ghetto shit with 12 from batteries. The sound could be from a servo motor like windscreen wiper or something pinging off the electric window motor, possibly the thermo fan.