Skip the auto shop - Our mechanics make house calls

Q: Loosing power

asked by on

I just replaced the battery and starter I had to jump it to start I let it run for about hours turned it off it still wouldn't start back up unless I jump it once it on the lights go deam some time

My car has 136000 miles.
My car has an automatic transmission.

A: There a few things that could be happening ...

There a few things that could be happening here. Number one, you could have a draw that is draining the battery. If this is the case, you will need to do a draw test that is done with an amp meter. Most multimeters can handle up to ten amps. Usually that is sufficient to test for a draw. Of course, you will need to understand and have access to the correct tools to do this.

If you have a drain on the battery, charging it for a few hours at idle with the alternator is often no sufficient. Alternators don’t charge efficiently at idle and they are not designed to charge batteries anyhow. They are designed to maintain the electrical system of your car only. Charging a dead battery is a different process. Doing a specific gravity test on your battery is the only accurate way to know its state of charge. A load test tests the batteries ability to produce the necessary current to start your motor.

What I think is going on, if I am interpreting your description correctly, is you have a bad connection in the starting system. Your starter requires much more current to work than every other system in your car. So if connections aren’t up to par, it won’t work. Keep in mind, what looks like a good connection to our eye, does not mean electricity agrees. A jump start could add just enough voltage to the system to overcome the poor connection.

Which one of these is the case will require some diagnosis. I recommend the following inspection to help you out; Car is not starting inspection which can be performed by a certified technician from YourMechanic at your home or office.

Good luck!

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!

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: RPM revs high

Hi and thanks for contacting YourMechanic. Check the IAC (idle air control valve) to the engine. This will cause the RPM's to fluctuate up and down to a dramatic amount. Look at the wiring to the IAC and make sure...

Q: If I am going to buy a remote starter for my 2012 Ford Escape, do I need to buy a certain model or kind?

Hi there. For the remote starter key fobs for your vehicle, you can buy them at any local parts retail shops. I recommend buying a remote start key fob from the dealership or a shop that deals with OEM parts....

Q: Can't find a parasitic drain?

Yes, your amp could be staying on. Feel it and see if it's warm. Disconnect it to confirm. Using a low amp probe (amp clamp) around the battery cable is the easiest, most repeatable method to measure battery drain. Measure...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...