Will not start after sitting a few days

PINOYDOY

MEMBER
1 POST

99 GMC Suburban K1500 w/ V8, 5.7L engine - engine won't start after 2-3 days. After jump starting one day, it will start the next day; let it sit 2 days without using vehicle, the battery is completely dead. It'll jump start but you have to keep using it daily otherwise, the battery gets drained. Alternator checked out; replaced battery; replaced a fuse (30Amp); still have the problem. Help!

Aug 1, 2007 at 7:46 AM

SQM

✓Experienced Mechanic
6,383 POSTS

Hello,

This sounds like the vehicle has an excessive parasitic draw (current drain).
All electrical circuits with a battery will have some amount of parasitic draw, however due to any given faulty electrical component/circuit it can become excessive. Which will lead to the battery drain at a much faster pace.
This excessive draw can be due to a light staying on, like a glove box light, a malfunctioning switch etc.

In order to detect the draw, you will have to use a multimeter and measure the drain on the battery as you are removing different fuses for different circuits.

Here is a helpful video that shows how to do that test:

https://youtu.be/z5F7WpgjaRs

This vehicle should have less than 25 milliamps of parasitic draw.

I have attached parasitic draw test procedure below.

Please let me know if you have any questions.
Thank you.

Images (Click to enlarge)