06 Ford Mustang Electrical

Pulled into a parking lot with the radio and headlights on. The radio turned off by itself and then the radio screen said “low battery.” I pulled into a parking spot and revved the engine for a few min and the little volt meter on the dash was on the low side but then it jumped back to normal and was fine. I turned the car off went shopping came out and the car started right up. Went home without a problem. What could it be? The only other thing out of the ordinary was earlier in the day when I first turned on the car it smelled like burning plastic. I thought I may have run a plastic bag over or something like that. The smell went away as soon as I started driving. I do not know if the smell is linked to the electrical problem but it is the only thing out of the ordinary that has happened.

It’s pretty likely you have a failing alternator, which just means that so far, one or more of four diodes has failed. Your battery is four years old, probably okay, but it is being drawn on to keep the engine running and the headlights shining and the radio on, etc.
The radio is just a symptom. You are losing the charge in your battery to run the car. The radio should work fine when you solve the charging issues. Have the alternator and battery tested right away.
The plastic burning smell is a concern and you should mention it when you have the charging system tested.

It could also be a worn belt slipping. This could cause a smell and voltage fluctuations.
Another possibility, other than a fried alternator or regulator, could be a fusible link in the charging or power supply circuits starting to fail.

If the car still has the original belt and depending on the mileage you might take a look at that first. At least it’s cheap and easy.

This sounds like it may be the problem. When I was parked and trying to keep the car running to charge the battery the voltage gage was very low even when I steped on the gas. Then all of a sudden it went back to normal and has not been a problem. I guess it may just be wishsful thinking but that seems to tie in with the worn belt idea. I will have it checked out and let you know. Thank you.

If you had a bad belt, you would also be losing your power steering at times.
I suspect a fault in the alternator.

Ok power steering has been fine so I guess it is back to the more costly answer.

I’d have the belt and tensioner looked at. Did you drive through a big puddle and/or was it raining when this happened to you?

No puddle or squeaking. Not raining either. The car has 62k miles. I am not sure what has or has not been changed.

Also check the connections to the battery, the alternator, and the power connection to the main power panel under the hood for loose connections.

The connections look good. The belt looks good no cracks and it feels tight. I smelled the altinator to see if it smelled like the smell from yesterday and nothing. I do not see any melted plastic. When you say the main power panel do you mean the fuse box under thr hood? if so the connections look good. Should I check a fuse to see if it fried? Also I have driven the car 3 more times since the problem happened and it has worked perfectly. Nothing out of the ordinary.

I broke down and took the car to get checked out. The alternator was only putting out 30 amps and the battery was not holding a charge. He said that he was not sure which came first the crappy battery or the breaking down of the alternator. He was guessing that the alternator was going bad and was working to hard to charge the battery. So it overheated and some of the soldering failed. The battery in the car was one that I have never seen. It was called “Econo Charge” does anyone know about this brand? Could this have lead to the death of my alternator? Or could it be that the alternator was going bad and the previous owner of this car kept going through batteries so he just went with an off brand battery and the cycle just continued. The battery not holding a good charge making the alternator work harder and the alternator working harder and not putting out as much as it should could cause the cheap battery to fail? I hope it is done!