Car electrical problem.

My friends 2005 Mazda MPV has a problem. The symptom I was informed was the radio and the drivers power window are not working. So I grabbed my ohm meter and went down the fuse panel looking for bad fuses. Murphies law held true and I managed to go though every fuse before finding a bad 25amp fuse. I grabbed a new fuse thinking problem solved and put it in. It burned out instantly. I then tried a wire to jump it and found there must be a dead short somewhere.

My assumption is a positive came loose somewhere. It seems odd to me that the radio and one power window would be on the same fuse however.

Most likely I will send my friend on her way to a mechanic or dealership. I think she still has a warranty on the car.

If I have time I may investigate it further. Anything obvious I’m not thinking of? Where/how would I start looking for the short?

Murphy’s Law informs me that the problem will be in the motor for the power window, because that’s the more difficult area to access.

I gotta say that if this is your habit you don’t need Murphy to create problems. When you know that current in excess of 25 amps is flowing, you probably don’t want to provide a path around the fuse.

Is there enough access to the radio and/or the window that you could disconnect either? If so, it should be possible to determine which is causing the problem (or if it lies elsewhere).

But if the car is under warranty, I’d say you should hand the problem to the dealer.

Look for a bad wire where they go from the car’s interior to the door. It has to bend every time the door is opened and shut. Take it to the dealer if you don’t see a problem there. This is if nobody installed after market equipment. The doors and radio might not be the bad part of the circuit either.

My friend does have a warranty on the car still, so the friendly folks at the dealership get this one.