A/C Problem?

Vehicle: 2015 Subaru WRX, 100K miles

So, Friday, 7.10.2020 I was on 75N going about 80 mphs when my rear driver tire blew. Swerved for a little before pulling on to the side without hitting anyone or damaging the outside of my car. The destination I was heading was still about 1.5 hours away so I changed the tire and got back on the road. On the way back from the destination, same day, about 4 hours later I noticed that my A/C was blowing hot air.

After a while the A/C just shut off entirely, but I noticed that the display on the dash was still showing like the A/C was blowing, but no air was coming out. I turned the car off and back on to see if it would reset , but it didn't. When I tested the A/C controls the display stayed off and no air was coming out. I made it back home with no A/C. 

Yesterday, 7.11.2020, I replaced the fuse to the A/C (10 Amp) with another (10 amp easy I.D. fuse that lights up when its blown) and it blew immediately. I just figured that one was a cheap one and tried another that look exactly like the one I removed. That lasted for about 5 mins before blowing. I tested another of the same 10 amps and 5 mins later that one blew as well. 

I recently installed a new radio (1-2 months), and the A/C control sit below it (radio) so I checked for any touching wires, re-wrapped everything to be sure, and tried another fuse, blown. Checked the A/C relay, and it's not the relay.  

Any suggestions?

2 Answers

  • M.
    Lv 7
    4 weeks ago

    Did you tap your high power car radio into the same circuit as the heater/a.c. control? 

    Did you try driving with the a.c. on and the radio off? 

    Circuits in newer cars are just big enough to do the job.  The louder the radio is, the more current it draws. 

    If it is connected to the heater a.c. circuit then find another power source. 

    I don't have access to a Subaru wiring diagram at the moment. 

    -General automotive mechanic since 1972

    -A/C repair since 1980

  • Anonymous
    4 weeks ago

    Clutch coil or blower motor (if motor is fed from same fuse) is likely shorted or there is a shorted wire.  Disconnect the connectors to the blower motor and compressor clutch coil and see if the fuse still blows with the engine running, AC on and the blower on.  If it does, there is a shorted wire in the circuit. 

    If it does not, check coil resistance and blower motor resistance with a multimeter.  You can try turning on fan without turning on AC and see if the fuse blows.  If it does,  motor is likely shorted.  If it does not, clutch coil is shorted and you will need a new coil or a new compressor. Disconnect clutch coil connector and see if the fuse blows with AC on and blower On.  If it does not, clutch coil is shorted.  If you have a clamp ammeter, check amp draw on the coil and blower motor.

    Watch a professional mechanic troubleshoot a blown AC fuse by checking the amp draw on the clutch coil when the engine is running to obtain a correct diagnosis.


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