paulroad

you may want the check the main harness for splices indicating past work, or perhaps some water damage from the past.

As for the temp sensor, its grounding out. You may want to replace this.

Ex-PzKW Cdr

Seen that several times

deba0016

I can charge the battery in my garage without running the car and it will drain dead in 24-48 hours.

I guess to prove that I would need to compare my .83amp current draw while sitting with someone who has no issues. Right?

btw, I appreciate the help

deba0016

There are no signs of water damage and there has been no aftermarket accessories or anything like that added to the car. The only thing I can think of is that a dealer replaced the air compressor for the air suspension which is located near the navigation computer and amplifier. Maybe they botched that job.

It sounds like no one really has any experience with similar problems. It would have been helpful if someone knew what a common battery load is like I asked about but I doubt I will get that information. I think I need to spend some time with the best wiring diagrams or troubleshooting available for this car. Does anyone have a suggestion for that? Bentley manual specific enough?

samm

Tell me how to check for elect. drain & I will check my car for comparison.

drivingforever

The Bentley manual is OK at providing schematics, but it's not the "end all, be all" because there are some things (like the steering wheel buttons) that are not shown in it. The schematics also don't show wire routing, they only show connections and grounds. Wire routing is something you'll just have to trace, AFAIK. I might be able to scan some for you next week if you'd like.

A one amp draw would probably be enough to drain the battery over the course of two days, so I think you've located the culprits.

Edit: Those signal/voltage too low codes really bother me. If there's resistance at any point in a circuit, voltage will drop, which causes current (amperage) to go up to maintain the same power draw. Then the wire or connection will get warm, which causes even more draw because hotter conductors have more internal resistance.

Here's a couple of things to check: Follow the ground cable from the battery post and find out where it terminates, including all smaller taps. Make sure these are tight and not corroded. Do the same with the positive cable from the battery.

You may also want to remove the interior panels from the driver's footwell and inspect the back side of the fuse panel, checking for loose connections, as well as any grounds you find in that area as well. (I think Audi tends to run grounds to just a few key points, so a cluster of brown wires attached to a stud would be one of those ground points.) Put a wrench or a nut driver on every fastener you run across, or if you find one that looks kinda crummy or is pretty loose, remove it and clean it before tightening.

Good Luck.

paulroad

if my car worked fine prior to work that anyone did.. including a dealer... and now there is a problem. I'd be back there ASAP to tell them the problem.

Homegrown-MN

As suggested, you're welcome to stop by again to clear the codes and drive it longer. However, I'd recommend stopping by SCI and see what Chad and Ben can offer in advice after they look it over. If you will be a customer, they will often look it over without charge.

/K

P.S. The PBR was a nice 'night cap' before hitting the sack. Thanks.

deba0016

I understand if you don't want to do this because it will reset your clock and your radio settings. But what I do is disconnect the ground from the battery, then i connect a multimeter set to DC current and connect one end to the battery terminal and the other to the ground battery cable. Then close the drivers door and take a reading. Thanks if you try it!!

deba0016

The only issue is this work was done before I owned it. Also, i have no idea if this problem cropped up at the same time the compressor service was done. I guess I need to thoroughly troubleshoot the radio and navigation circuits (which unfortunately are tied to many different functions)