Skip the auto shop - Our mechanics make house calls

Q: Problem with battery discharging over a couple of hours. Alternator getting hot while running very quickly.

asked by on

just bought car a couple of days ago,ran fine washed it,cleaned engine,noticed when i stated it and let it run,tuned rear wiper on,and it wouldnt turn off.i pulled fuse for rear wiper and left it out.wife cleaned carpets and in that time battery went dead about 1.5 hrs.so i jumped it let it run,took it for about a 45 min, drive.shut it off, restarted just fine.next morning it was dead, this has happened 4 times,i noticed that alternator gets hot while running pretty quickly. i have a charger that checks the alt,and also the battery separately both came back good, there is a porcelain resister on passenger fender well also getting hot.please help me figure this out,wife needs car for work,im off of work from injury and low on finances. thank you so much

My car has 215000 miles.
My car has an automatic transmission.

This may be related to a voltage regulator malfunction. This is the resister on the passenger fender well that you are referring to. This is a device that monitors the charging system to be sure the battery is charged at the rate and voltage that it should be. When this is not functioning correctly, this will cause the battery to die intermittently which can also cause the alternator to work harder than normal as well. I would recommend having an expert from YourMechanic diagnose the charging system issue in person to verify the problem and proceed with the proper repair.

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
  • Home
  • Questions
  • Problem with battery discharging over a couple of hours. Alternator getting hot while running very quickly.

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: Diesel trucks idles fine but after driving doesnt idle

You will need to have the charging system and batteries tested to see if you have a defective battery or the charging system is not recharging them. Since you say you jump started engine tells me the batteries were dead...

Q: Car making squeaking and growling noise from under the hood by alternator

The shaking and stalling out as you describe can be caused by a variety of issues. When this happens there is likely a Check Engine Light on that should register a fault code in the car's computer. I would recommend...

Q: Temperature gauge goes up slightly then back to normal

If you are not running the a/c system at the time you see the temperature gauge go above the middle of gauge and back down every few minutes then this is normal cycling of the cooling fan. If you turn...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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 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...