OK, I've been fighting a battery drain for weeks, recently noticed the noticable click from the ABS area when vehicle is parked - have searched the forum and found there was supposedly a TSB on this but cannot find it on the net. I think this is the cause of my battery drain! Anyone know what is the cause and how to fix it?

 

If you are referring to the faint ticking pulses coming from the ABS valve block, and you find it "loud", you are in an extremely quiet environment.

Seen no indications of such ABS noise being a cause of considerable battery drain. That noise is the nature of the beast and lasts several minutes after a door/hood is opened. No information found from the ABS manufacturer to learn what goes on. Guessing, the system starts a self test at any electrical disturbance (like entering the vehicle) as 'preparing' for a ride.

Check other battery drain paths first.

 

Followup question for personal knowledge. On the driver side of the engine I hear a slight click but it sounds more like an electrical pulse to me. Not loud and can really one here it when hood is open but always thought it was weird. I thought maybe it was the alarm system but sounds like maybe this is what I am hearing. That being said mine car sits for weeks at a time and this has never drained my battery.

I just recently experienced some weird battery issues in that it could sit for days and be fine then drive it and would be stranded after it sitting for just a few hours. I ended up just removing the main ground and cleaning connection only to discover the signal wire (whatever the small wire is) on my alternator was broken in half. I am guessing this happened when my clutch fan exploded as I found pieces of it under the alt as I repaired the wire and thats about the same time the issue started. I ended up having to replace the alternator as the bolt on the alternator for the wire to attach to was also broken. I think it can be fixed so will use as a spare if ever needed

 

Has your truck been converted from air springs in the back to coils? If so there's a good chance the drain is due to the air springs/coils setting the SLABS having not been changed to coils. Well documented on this forum, including by me. Removing the SLS relay doesn't solve the problem.

If your truck has rear coils and you aren't the original owner you may not know for sure whether or not it once had air springs. If you're not sure take a look under the truck, under the driver's door. The SLS pump is located there in a plastic box mounted to the frame, I recall. No box, no pump. But if the box is there the truck once had air springs.

What year is your truck? I know that all '99s and I think all '00s at least came with air springs.

 

That was it! Found the thread about the SLS disable - removed the ground wire and problem fixed!

 

Ah Grasshopper ... don't be too hasty. Live with her a few days at least before declaring victory. No need to jinx it.

If this is the thread you read you might have also read that when I tried disconnecting the SLS ground I got warning chimes when driving. That's why I went ahead and had the SLABS setting changed from air springs to coils. (I took the truck back to the idiots who'd changed out the springs years before without finishing the job by changing the SLABS setting. They bitched and moaned but eventually did it.)

If you don't have access to a TestBook or other device like a Nanocom to change the settings you might try disconnecting the SLS connectors from the SLABS box. I've attached two pages from RAVE that show those are connectors C0654 and C0655. They don't support any other functions so pulling them shouldn't affect anything else. Worth a try, it seems.

 

Yep, had the alarm thingy going off just like you did - and I had no idea who originally replaced the springs (assume it was years ago) - and I had no intention of paying to have it done (I am a cheap SOB). Here's what I did:

Used the SLS relay and wired it in to the ground wire - powered the relay off of the fuel pump wire at the fusebox (brown connector). Now it disconnects the ground when the truck is off, connects it when truck is on. Voila', no alarm and no battery drain.

Thanks for marking the trail with breadcrumbs all who blazed the path!

 

Wow. Very clever.

I'd still like to see the next person who has this problem and finds this thread to try unplugging the SLS connectors from the SLABS to see whether or not that works without triggering any unintended consequences.

 

mln01,
I was experiencing the same issues with an battery drain. After changing the battery and still seeing the same thing, I went through the trouble shooting exercise and narrowed it down to fuse #11. I found this thread after searching the forum. We bought the truck about 6 months ago and didn't know a lot about the background. This thread led me to investigate the SLS situation and sure enough, I have the SLS pump, but there are springs/coils on all the corners. The air lines are still present and just tucked up inside the wheel well not connected to anything. My first attempt was to try your solution of disconnecting the two connectors at the SLABS ECU. We immediately got the SLS warning on the dash but decided to drive it around and see what happens anyway. I will report back as to if this solves the battery drain or if I will need to run the relay jumper solution detailed by extinct.

 

I should mention that for some reason even with the relay solution the alarm goes off the first time I start the truck for the day, after that the alarm does not go off the rest of the day. I therefore have had to get in the habit of switching the ignition on twice the first time I start it for the day.