Skip the auto shop - Our mechanics make house calls

Q: Can't find a parasitic drain?

asked by on

I have went through the fuses looking for where the drain is coming from, the only thing I haven't checked is the amp. But I rarely tour stereo on, could this still be the culprit?

My car has 152400 miles.
My car has an automatic transmission.

A: Yes, your amp could be staying on. Feel it ...

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 the B+ wire at the alternator as well. Feel relays for warmth and key out of the ignition while doing this. Remember it can take 10-30 minutes after running for all modules to go to sleep. If you pull a fuse then put it back it can wake up a control module. You have to leave it out and move on with testing. Instrument cluster and rear wiper motors are a possibility, too. There is a lot of electrical content in your car, so you may want to double check the fuses. You’ll also want to verify whether the battery really is good! If you are still having trouble, you can always get a certified technician from YourMechanic to come to your car’s location to diagnose your battery and let you know what needs to be fixed.

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: Engine temperature keeps going up

Hello. The cooling system is designed to keep the engine at operating temperature. Hot coolant from the engine flows through the radiator, which lowers the temperature. The lower temperature coolant is then returned to the engine. The primary cooling system...

Q: We are replacing rhe water pump and the special tool is not working it just keeps slipping the water pump is very rusty need help

The replacement of the water pump on your vehicle is more complex than the average vehicle and does require a special GM tool (J 38816-A Water Pump Remover & Installer), therefore if you desire you can request that a certified...

Q: Dashboard lights won't work at night

With the dashboard lights not coming on, the car is not safe to drive as you are unable to see warning messages on the dash and the speedometer. The most common causes for this dashboard light problem is the lights...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.