Dead battery, again ... locating parasitic draw

[ree]

Originally Posted by BITURBOAMG

Did this ever get worked out?

Unfortunately, no. It happens very rarely.

I have a suspicion that it's something whacked with the cigarette lighter in the center console. The past three times I've had a dead battery, I am certain that I had a device plugged into that jack for power. The prior times, I can't recall if it was the case, but think it might be. There doesn't seem to be any debris in the lighter jack to make contact, though.

Your problem sounds a lot wierder.

[HUMTECH]

The ignition switch can be adjusted, if they are not installed accuratly they will leave accessory power on. Easy way to check install key halfway and turn lock cylinder forward firmly and see if truck power up. If so ign switch needs to be removed and adjusted until this does not occur, seen it and repaired it many times. As for battery draws elsewhere have seen many air suspension relays fail and cause A draw, as well as onstar, sometimes if your not A subscibed customer the gps will intermittantly look for A signal waking up the module, pull the info fuse if you dont have A subscription. Also hvac control heads and stereo amps have been know to cause A draw.

[H2R]

Hook up a multimeter and start removing fuses, you can narrow it down fast. This will give you an idea where to start to look. To troubleshoot any other way may have you looking much longer.

[tower]

Quit screwin' around! You're always screwin' around!

IT's fairly easy to track down a draw. Go to any good auto electric-shop and have them put a field ammeter on your primary battery cable. It has a kind of ring clamp which fits around the cable without even disconnecting or interrupting it. If there is a draw when the vehicle is off it will show up. That will quell the dealer's argument that the problem is with your yellow top (which I doubt). Then they just trace your wiring as it branches off the primary through the fusebox and downstream from there, locating the offending lead. DONE!

[HUMTECH]

An amp clamp I believe is what your talking about? if so, they are not near accurate enough as they only measure amps, you need to measure mA. You should see about a 25-40mA draw which is normal once all modules have powered down, typically within 1-5 minutes. any more than that after 5min and the draw is excessive. Install A battery disconnect switch between the neg cable and the neg bat post close the switch so current is flowing, attach amp meter to either side of switch and wait 5 min, open the switch and now the current will flow through the meter. Use the 10A scale so if its high you dont blow the fuse in the meter, should see about 0.025 to 0.040 on that scale.

[tower]

I believe Amp Clamp is a brand name like Kleenex. I know Fluke makes these. However, you are quite correct about the measurement. It is milliamps as opposed to amps. And there are DC clamp meters which go that low. Thanks for your correction, HUMTECH!

[mdoyle]

What is the adjustment for the ignition switch? Is is a matter of moving the lock cylinder or some linkage down the column?

I replaced the switch a few months ago and the problem went away, but now within the past few weeks it's come back.

[HUMTECH]

When you remove the ign switch(not the lock cylinder) you will see that it has a plastic wheel with teeth on it. Rotate it a little and reinsert ign switch. test it and readjust if neccessary. The ign switch will just slide out of the housing when A small pick tool is used to depress the retainers on both sides.