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.

A: This may be related to a voltage regulator ...

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

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: Car won't start

Hi there! There first thing to check is your battery voltage. This can be done with a multi-meter. Simply place the red probe to the positive terminal and the black probe to the negative terminal, you should get at LEAST...

Q: Car drove fine until headlights turned on

Hello there. It is very possible. A charging test will need to be completed on the alternator. If the alternator passes the charging test, then the wiring connections both at the positive and ground side of the battery need to...

Q: Seeking an opinion on the new Forester

test

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...