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 i jumped it let it run,took it for about a 45 min, drive.shut it off, restarted just 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・Save up to 30%

Get a quote

What others are asking

Q: Car isn't cranking

It sounds like you may have a problem with the battery cables. Check the ends by the battery thoroughly, especially if they have been replaced by universal ones. The main ground cable runs with the starter positive cable and is...

Q: Battery won't stay charged

This is a common problem when the voltage regulator is failing which is potentially due to a faulty ground or connection. I would start by checking the battery connections and cables to be sure they are not dirty or corroded....

Q: Noise when turning to the left

It's difficult to say without inspecting the vehicle firsthand just what the noise is. A worn or damaged wheel bearing will make a rotational growling noise that often gets worse when turning. To check for a bad wheel bearing, lift...

Related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...