Skip the auto shop - Our mechanics make house calls

Q: I have a parasitic drain of 150 milliamps from my alternator, is that normal?

asked by on

2002 Ford Mustang Convertible OEM Radio No add-ons If my car sits for a few days the battery goes dead. The battery charges fine and holds the charge. I have done a parasitic drain test that saw 3 issues.

Radio causes small drain to be expected. Dashboard cause a small drain not sure why? Alternator is the largest source of drain .15 amps.

Should an alternator cause any drain on a battery after it is turned off?

My car has 50000 miles.
My car has an automatic transmission.

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
  • I have a parasitic drain of 150 milliamps from my alternator, is that normal?

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

You may have a bad fuel pump. The fuel pump may have been burned up if you ran it out of fuel or ran it low a lot of times. The fuel pump uses the fuel to keep the pump...

Q: my battery light is on when the car was started, in the morning whiles going to work it was normal, it was till I closed from work

Hey there. I would test your alternator. Use a multi meter to ensure your alternator is reading 13.8-14.2 volts while the vehicle is running. If it is not, try replacing the alternator and see if it removes the battery light....

Q: Car takes time to start

In many cases, a failing sensor can cause an extended cranking time or multiple attempts to get the vehicle started. The problem may be difficult to track down. Have an experienced automotive technician, such as one from YourMechanic, inspect the...

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...
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...
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...