A parasitic draw is when a an electrical component continues to draw down your vehicles battery after the vehicle has been shut off.  This happens quite often in conjunction with water damage. A parasitic draw can be difficult to pin down, and the price for diagnosing them can vary widely from shop to shop.

 The first steps in diagnosing a parasitic draw come from asking the customer the right questions.

How long have you had this problem?
Has there been any recent water damage to the car?
How long after you turn off the car does  it take for the battery to go dead?
Does it happen consistently?

2) Testing the battery and making sure it can hold a charge

3) Do a complete diagnostic scan of the vehicle.  Often the system that is malfunctioning will have trouble codes

4) Connect a Ohm meter between the battery and the car to determine the size of the draw.

There are quite a few more steps in tracking down the source of the electrical draw, but a good technician will always follow these basic rules.

The price in diagnosing a draw lies in the amount of labor time it will take your technician to track it down.  A more experienced shop often knows where to look first since they are familiar with certain electrical components that are either poorly placed and prone to water damage or simply defective and known to cause issues.

Choosing a shop that specializes in electrical diagnostics is crucial in keeping the cost of these repairs down. At L&M Foreign Cars we’ve been diagnosing and repairing electrical draws for over 50 years.  We know exactly how to approach electrical draws and are fully equipped for this type of work. We specialize in BMW, Audi, Range Rover, Mini Cooper and Mercedes. If you think your vehicle has an electrical draw feel free to give us a call or stop by, we’re always happy to help!

ASE Certified logoAPRA logoAERA logoiATN logoSAE logoPERA logo