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Q: Car won't start. Electronics work, but loud screeching noise comes from fuse/battery boxes in the trunk when turn ignition key.

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My magnum has been having a multitude of starting/engine stopping problems. First the engine died whenever I gave it gas, which made it impossible to drive. I took it to the dealer where they looked at it for a month, and found nothing. They checked fuel, air, replaced all valves. They changed the spark plugs and then the problem was ironically reversed--it would drive, but it dies once it goes below 500 RPM, can't idle, have to keep foot on gas in neutral at stoplight. NOW suddenly the car won't even start. When I turn the ignition key the electronics go haywire and there is a loud distorted screeching noise coming from around the battery and fuse box in the back of the car. I tried jumping it and the electronics work now, but it won't crank, noise remains. I don't know if any of these problems are even related. Dealership is at a loss. No one can help me and I've spent a thousand dollars just in diagnostics.

My car has 75000 miles.
My car has an automatic transmission.

A: Hi and thanks for contacting You Mechanic. ...

Hi and thanks for contacting You Mechanic. There could be a lot of issues that could relate to this topic, however, I have narrowed it down to 4 things to check.

First check the battery and make sure that the cables are tight. Perform a load test on the battery and make sure that the battery is functioning correctly. Most dealerships will not check a battery correctly and they should on every vehicle.

Second, check for any loose cables to the starter and see if the wires have any corrosion. If there is corrosion then the wire needs replaced (if the wire is green).

Third, check the MAF (Mass Airflow) sensor for if it is dirty or damaged. If you see that it is dirty or damaged, then it needs replaced.

Last, if everything works then the computer has a burned a ground circuit within the computer housing. Check the computer harness for any burned pins and if all of the pin are good then the computer needs replaced.

If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from YourMechanic, that can assist you with diagnosing the engine starting issue.

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