Posted on 6/25/2025
If one day you turn on your vehicle’s a/c (or heat) and there is no air coming in at all, or the fan shuts off without rhyme or reason, there is a good chance that the blower motor relay is malfunctioning. This tiny switch can wreak havoc with your vehicle’s ac or heating. The blower motor relay is an electronic switch – it controls power coming to the blower motor. When you turn on a/c or heat, or change fan speed setting, blower motor relay ensures that the blower motor gets just the right voltage to run as desired. When the relay starts to malfunction, a variety of symptoms may appear – no air at all, or intermittent fan failure, or just one fan speed – all of them implicate the blower motor relay. However, while the relay may be implicated, it takes a professional mechanic to verify and find the true cause of the problem – for example, if no air comes out of the vents, it could be the relay, but it could also be the blower motor itself that&rsq ... read more