Skip the auto shop - Our mechanics make house calls

Q: Reversed jumper cables and now car won't start even with a new battery.

asked by on

My car has an old battery that died. When jumping off the cable got reversed causing the battery to spark and the cables to get hot. I purchased a new battery, but the car will not start.

A number of things may have occurred when the jumper cables were reversed. The battery cables themselves may be fried and require replacement in order to start the vehicle. The PCM or the main computer in your vehicle may also have been fried in the process but the battery cables are the most likely cause. Even more unlikely but still a possibility is that your starter is even damaged. The first thing I would recommend is to have a qualified professional inspect your starting system for any signs of burning. These signs will be most noticeable where plastic exists such as the battery case of the old battery and the insulation of the battery cables. Have the technician also inspect the fuse box for any blown fuses or signs of burning in that area as well.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • Reversed jumper cables and now car won't start even with a new battery.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: New front tires and aligned, but tires are different sizes

I would have the tire size double checked as a 60 series tire will generally be taller if the profile number does not change. The tire light is probably due to a failed tire monitoring system initialization which should have...

Q: 2002 Wrangler. Replacing an air control valve. After installing, is there anything special we have to do?

This is a relatively simple process that generally includes unhooking the old idle air control valve and plugging in the new one. Here are some simple steps to follow: Scan the computer system in the car for codes Check...

Q: Cylinder five misfire code

In most cases a misfire condition can be corrected by inspecting and replacing the spark plug and ignition coil for that cylinder. For your Ford Expedition, I would recommend replacing all of your spark plugs and ignition coils to be...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.