tommyleea

2000 A4 Quattro 2.8..Car had been sitting for a couple of years. Original problem was overheat, but no money to fix. I decided to buy the car. When the battery was connected, smoke emerged from the dash (I wasn't present at the time), battery disconnected, and it sat for a couple of months before I could get to the car. When I connected the battery, there was no smoke. The car started. I found a pinhole in the oil cooler hose going to the oil filter housing. Replaced the hose, started the car, and let it run. Temperature remained good, but ABS light is on, and the brake light is flashing. The issue I am fighting now, is a huge current draw. I removed the negative battery cable, put a 30 amp fused wire between the cable and the battery post, and it blew the 30 amp fuse. All the fuses in the fuse box are still good. I assume there is a dead short some where, but it seems odd the fuses are still good. Everything seems to work on the car, and I drove it a couple of miles without any issues. The A/C compressor doesn't engage, but the blower motor and control unit seem to function. I don't see any obvious burn areas. Any ideas? Also, how do you remove the panel under the dash on the drivers side. It looks like there are several relays under it, but I don't want to break it. I still need to get a service manual, but any advice would be appreciated. Thanks..

GTA_Driver

There are a few screws underneath and on the side where the fuse panel is. They are visible to the naked eye.

turbo510

There are 3 or 4 (on my '96) screws, a couple behind plastic trim that you pry out first. One is revealed when you take the fuse cover off. One should be at the lower right corner of the panel. There are some higher amp fuses up under there, including circuit breakers for the power windows. Check all of those out, and look for discolored wires, or distorted relay covers, using a bright flashlight.

The AC compressor not working doesn't mean much unless you know that there is enough Freon charge. A low pressure switch will keep it from running.

Instead of a 30A fuse, next time use a 12V light bulb, and pull fuses until you find the circuit drawing all that current. You might even try disconnecting the ABS connector, and under the rear seat, the alarm module's connector.

Edit: 30+ Amps at 12V means something is getting really hot. That shouldn't be too hard to find.

tommyleea

I didn't think the A/C was an issue either, just info. I agree that it should be easy to track down the problem with that much amperage. More to follow, and thanks for the info. Cheers..

tommyleea

OK, I removed the panel under dash on drivers side. Nothing obvious to the eye. I guess my question is, with that much current draw (at least 30 amp) shouldn't something be hot or blown? I felt all the relays and they are normal. The 50 amp fuse is still good. Where do I go from here? Should I start pulling relays? I am not sure what I can connect between the battery cable and battery post for the test. My DVOM already blew the fuse (of course). Nothing out of the ordinary behind the glove box. I disconnected the ABS module with no change. The alarm under the rear seat isn't warm, but I didn't disconnect it. Any more ideas? Thanks

TommyJ

mtroxel

I'm betting on a dead short to ground with that sort of draw. If that's the case, you could pull both cables off the battery, then put a meter between them and set it for 2000 Ohms. You should see about 2,000 Ohms, maybe more. The only closed circuits should be the radio trickle and locking remote sytem. I'm betting you'll see well under 10 Ohms, maybe 1 or less, even 0 with your short. Start pulling fuses till you see it skyrocket. This assumes your short to ground is behind the fuse box, but it's a good way to start.

tommyleea

I am a little confused. If I disconnect both battery cables, I should read around 2000 ohms or more. Where does the 10 ohm or less come from? Then, why would it skyrocket by pulling fuses?
Thanks for the time.

mtroxel

I will read 10 Ohms or less.....maybe even 0 Ohms, because you've got a short to ground somewhere. When you pull the fuse on the circuit that has the dead short to ground, the Ohms should be normal again. Then you know what circuit to track down.

tommyleea

Sorry, you will have to use the kiss principle on me. Where am I measuring to get the 10 ohms or less? When will it skyrocket?
I am not sure where my testing points are at. Thanks

mtroxel

It will skyrocket when you pull the fuse on the circuit that has the dead short to ground in it. If you have a dead short to ground, you should read very low resistence...probably less than an Ohm. It's like puttting the two probes of the multi-meter together. They complete a circuit, and you'd read 0 ohms. With a 30 amp draw, that's probably what you have somewhere in your car. On some circuit ground and positive are shorted together sucking your battery dry. A healthy B5 will read very high resistance between + and - because the only thing completing a circuit is the radio anti-theft stuff and the remote locking/theft stuff, and there is a lot of circuitry between + and - in those systems. You have a circuit that is essentially connecting the + and - on your battery. That's the circuit you are looking for.