Q: I think my VAM is bad. How do I test it to verify before buying a new one?
A: Assuming it is clean inside the vam, it is plugged in, etc. Follow the procedure below to test it:
VAM Testing Procedure Used to detect faulty/out of adjustment VAM
Testing for DC Voltage with your negative (-) lead on the signal return wire and probing wires below with the positive lead: VREF (orange) = 5.0-5.1v VAT (light green/purple) = ~2.8v @ 70*F VAF (white/black) = ~.25v @ 0%, 4.5v @ 100%, .8v-1.0v at warm idle (this varies on idle speed) You must also make sure that there are no dead or low voltage spots when the door sweeps from .25v to 4.5v. If this is the case then the VAM is shot and needs replaced.