My 2015 wrx has been giving me issues lately. Starting last spring the car would just randomly not start, sometimes it turned over sometimes it didn’t. Dealer said then found no problem with the battery. It stopped for months, now it has started again. Also my AC compressor pulley will spin for a few seconds and make an odd noise, then stop for a few seconds, the repeat the process. When the AC compressor spins I can hear it kick in from outside the car and the exhaust note increases a bit as well as if the idle rpms jump up a bit
My car has 34831 miles.
My car has a manual transmission.
The cycling of the AC compressor is normal as the compressor cycles on and off. You may also hear a bit of a change in the exhaust as this happens. The computer will automatically compensate for the additional load the compressor puts on the motor by adding additional fuel to the motor. With regard to the vehicle not starting intermittently, this may be related to a number of things, but if the motor eventually turns over it is likely that the problem is not related to the battery or charging system. I would suggest checking the starter relay as this may produce the symptoms you are describing. The starter relay directs power from the battery to the starter solenoid which then engages the starter when you turn the key. When this is not working properly, you may notice intermittent starting problems including no response when turning the key to start. Generally, when this does fail, it does so very randomly and usually without warning other than intermittent starting. The power from the battery will still power other accessories such as radio, horn, etc., but you may not have any power to the starter. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.
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