Q: Battery dead car won't run

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Ok question. So my friend has a 2007 mustang. She drove it to work fine she came out of work and car wouldn't start battery was completely dead. We jumped it was running fine then she started driving got s mile down the road and her car died. Thought it was the alternator got it running checked the alternator disconnected the battery ran perfect. Hasn't died since but then the lights keep flickering. While running I smelt the oil and the oil was running real real rich. All connections are good new alternator and battery. What do you think it use
My car has an automatic transmission.

Disconnecting the battery while the car is running to check the charging system may have been ok in older cars, however most newer cars with all the on-board electronics do not respond well to that old trick.

Things like the Electronic Control Unit (ECU) and Power/Body Control Modules (PCM/BCM) function by controlling, or completing, the ground for most switches and sensors under the hood.

Disconnecting the battery while the car is running can cause a short, or spike to ground right through those control modules. Running rich suggests that the ECU may be at fault.

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