firepop5

I have a 2006 with V6 and Shaker 500. Read up on related threads and many suggest a problem with the stereo. Tried the digital multimeter diagnosis-- meter between negative post and negative cable. With everything turned off, was drawing 2.8 to 3.2 amps. This is sure to drain the battery of a car parked for a few days. The funny part is I tried to identify the circuit with the draw by removing each fuse and relay one at a time. I tried the panel under the hood first, then the interior fuse panel. Could not find a fuse or relay that made the drain stop.

How many sources does the stereo system draw power from?

Are there any other relays, fuses or other sources I can check for this power loss?

SpartaPerformance

Y are you limiting yourself to just the stereo? Pull all the fuses and see where the draw is.

thedrod

I agree with Sparta. How about you pull everything and add them back one by one? Make sure you remember where they go. Let us know what you discover. I am having issues too.

I had the Shaker and had a dead battery after a week of not driving. I never had the problem after I removed the Shaker until this past weekend. I went to Hawaii for two weeks and came back to a stone dead car.

Art161

Unless you didn't tell us about all the steps you followed, you are doing it wrong. The computers continue to draw current for a period of time. If you disconnected the battery and quickly started reading current, you didn't give the computers time to power down.

1. Make sure the bussed electrical center (BEC) and smart junction box (SJB) are accessible without turning on the interior or the underhood lights.

2. Drive the vehicle at least 5 minutes and over 48 km/h (30 mph) to turn on and activate the vehicle systems.

3. Allow the vehicle to sit with the key off for at least 40 minutes to allow the modules to time out/power down.

4. Connect a fused (10A) jumper wire between the negative battery cable and the negative battery post to prevent the modules from resetting and to catch capacitive drains.

5. Disconnect the negative battery cable from the negative battery post without breaking the connection of the jumper wire.

6. NOTE: It is very important that continuity is not broken between the negative battery cable and the negative battery post when connecting the meter. If this happens, the entire procedure must be repeated.

Connect the battery tester between the negative battery cable and the post. The meter must be capable of reading milliamps and should have a 10 amp capability.

7. NOTE: If the meter settings need to be switched or the test leads need to be moved to another jack, the jumper wire must be reinstalled to avoid breaking continuity.

Remove the jumper wire.

8. NOTE: Amperage draw varies from vehicle to vehicle depending on the equipment package. Compare to a similar vehicle for reference.

NOTE: No factory-equipped vehicle should have more than a 50 mA (0.050 amp) draw.

Note the amperage draw.

9. If the draw if found to be excessive, remove the fuses from the SJB one at a time and note the current reading. Do not reinstall the fuses until you have finished testing. To properly isolate each of the circuits, all of the fuses may need to be removed and install one fuse, note the amperage draw, then remove the fuse and install the next fuse, until all of the circuits are checked. When the current level drops to an acceptable level after removing a fuse, the circuit containing the excessive draw has been located.

10. If the current draw is still excessive, remove the fuses from the BEC one at a time and note the current draw. Do not reinstall the fuses until you have finished testing. To properly isolate each of the circuits, all of the fuses may need to be removed and install one fuse, note the amperage draw, then remove the fuse and install the next fuse, until all of the circuits are checked. When the current level drops to an acceptable level after removing a fuse, the circuit containing the excessive draw has been located.

11. Check the Wiring Diagrams for any circuits that run from the battery without passing through the BEC/SJB. If the current draw is still excessive, disconnect these circuits until the draw is found. Also, disconnect the generator electrical connections if the draw can not be located. The generator may be internally shorted, causing the current drain.

Nuke

Excellent write-up, Art161.

157dB

Follow the workshop manual and do it like Ford would...

157dB

Follow the Ford way and be true to yourself...

I am stuck with 150mA of OEM draw but a custom battery tender/exerciser does the trick...

Blue GT Mustang

Don't forget if you have a factory alarm system that it is a continuous current draw.
If I know I won't be driving my GT for a week or more I hook up my Battery Tender to it.
It is on the car all winter also. The car will be four years old next month and still on the original battery. I have had a Battery Tender Junior hooked up to my lawn tractor for over five years and it is still on the factory battery as well. It seems my friends with lawn tractors are replacing their batterys every 12-18 months so it is a product I endorse and believe in. Sorry if I got OT.

timmbo

Exactly is how I do mine. I use a Battery Tender Jr. And before I get out of the car I push "menu", turn the Shaker "off" then manually shut off the radio.