drained battery

[BusBerd]

Just bought a new battery a week or two ago. I thought my old one was not keeping its charge. But now my new battery is dying. not enough juice to turn the starter.
I am thinking there must be a short somewhere that is draining the battery's charge. I took off the negative cable from the battery. I took ALL of the fuses out of the fusebox and the fuse out of the radio power line and the line that goes back to the sink pump. Then I tested to see if i would get a spark when I touched the negative cable back to the battery. I did. So this means that there is still something drawing power from the battery, correct?
So I thought I would check the connections at the starter today. I have a multimeter that I am still not sure how to use, but i am trying to learn how to use it.
Any other suggestions?
thanks!

[Amskeptic]

Any other suggestions?
thanks!

Disconnect the voltage regulator plug. Try your battery terminal little spark test. No more spark? You might have a diode leak.
I lived with one for years. I just disconnected negative from battery if car sat for more than four days.
Colin

[Adventurewagen]

I guess you could still have something shorted out and completing the circuit when you attach the negative terminal, but unless something is drawing actual power it may not be draining the battery like your thinking.

Edit: My bad, I see you have a 77...
What type of charging setup do you have? Do you have an alternator or a generator? Have you checked to see that your battery is being charged while the bus is running?

Next thing you could do would be to connect the battery, but with everything off start at the fuse panel and check for 12v and maybe you'll run across something that shouldn't have it. Might also try the radio with the power and key out to see if thats it. sometimes people run the yellow wire and the red wire to keyed power and permanent power and that could be the issue. Also, your lights will all have a ghost draw, you might want to trace out those lines and figure where they go. If you have a fridge that would too.

[BusBerd]

voltage regulator is the one on the right side of the fuel tank panel, right? above #1 cyl.
I'll check the bentley

[BusBerd]

What type of charging setup do you have? Do you have an alternator or a generator? Have you checked to see that your battery is being charged while the bus is running?

Next thing you could do would be to connect the battery, but with everything off start at the fuse panel and check for 12v and maybe you'll run across something that shouldn't have it. Might also try the radio with the power and key out to see if thats it. sometimes people run the yellow wire and the red wire to keyed power and permanent power and that could be the issue. Also, your lights will all have a ghost draw, you might want to trace out those lines and figure where they go. If you have a fridge that would too.

I have an alternator. I have not checked to see that the alternator is charging the battery while running. can i do this with a multimeter somehow?
The radio can be played while everything else is off and the key is out, But I took the inline fuse for the radio out while I was checking for spark at the negative terminal and still got spark.
Not sure what you mean about the lights. If I have removed all of the fuses, there could still be a draw (ghost draw) from the lights?
no fridge.
thanks!

[Amskeptic]

I have an alternator. I have not checked to see that the alternator is charging the battery while running. can i do this with a multimeter somehow?
The radio can be played while everything else is off and the key is out, But!

Do the reg plug pull test. When you had all the fuses out, you effectively ruled out all the consumers. So now you are narrowed down to harness/alternator/regulator. There are few consumers upstream of the fuse box.
Colin

[Adventurewagen]

I have an alternator. I have not checked to see that the alternator is charging the battery while running. can i do this with a multimeter somehow?
The radio can be played while everything else is off and the key is out, But I took the inline fuse for the radio out while I was checking for spark at the negative terminal and still got spark.
Not sure what you mean about the lights. If I have removed all of the fuses, there could still be a draw (ghost draw) from the lights?
no fridge.
thanks!

Its easy to check with your multimeter. Engine Off, ground the negative of the multimeter and check the battery. Should be 12.6 for 100%. Then turn the car on and check the battery again the same way from the same spots and it should read closer to 14v. It will probably only be 13.8 or so because you're at idle, but that would tell you if the alternator was working.

After pulling the fuse from the panel for the radio, did you check to see that it in fact was now disabled? Lights will pull a small ghost draw depending on the light, but I doubt thats causing your battery to die so quickly. I'm guessing you either have charging problems or you have a diode leak like Colin said.

[BusBerd]

I have an alternator. I have not checked to see that the alternator is charging the battery while running. can i do this with a multimeter somehow?
The radio can be played while everything else is off and the key is out, But!

Do the reg plug pull test. When you had all the fuses out, you effectively ruled out all the consumers. So now you are narrowed down to harness/alternator/regulator. There are few consumers upstream of the fuse box.
Colin

ok, thanks!
I'll check it out now.

[BusBerd]

OK, so I unplugged the voltage regulator and still got spark. Just for good measure I took out all the fuses again and tried it again with the voltage regulator unplugged and I still have a spark at the neg. terminal.
so what does this mean again??
thanks!

[BusBerd]

does this narrow it down to harness and alternator?
FYI, I had to swap out my ECU a few weeks ago. could this cause the drain? I had a VW shop diagnose the problem and they swaped out my ECU with one they had in the shop. If they swapped it out with the wrong one, could it be drawing power for some accessory i don't have or something???
thanks!

[Adventurewagen]

How do things connect at the positive side of your battery? do you have one clamp that has two splits, one going to the starter another going to other power devices?

I'm just wondering if you look at your starter/solenoid what would happen if you took off that end completely and then tried again.

Your bus is probably different than mine, but my heave gauge line runs from the positive to the solenoid like you'd expect and then has another line coming off the same terminal going to the front of the car to power other items. Just wondering if you could figure out which positive line out of your battery is closing the circuit.

sounds like its happening before it gets to the fuse panel.

[covelo]

I lived with one for years. I just disconnected negative from battery if car sat for more than four days.

And I thought I was cheap...

I would suspect the positive battery cable and the connections at the starter. The only time I broke down on the side of the road with my bus was when a badly connected heater box outlet burned a hole in the insulation of my positive battery cable. That stopped the bus fast. You may have something more benign going on down there that is causing a slow drain of electricity.

I would remove all cables from the ratsnest at the starter and only connect the big positive battery cable and try the spark test. Then add one cable at a time and retry.

By the way, to save yourself a lot of crawling and a potential explosion with your head in the engine hatch you may want to buy a cheap multimeter and hook it up with some long wires so you can do all of this while comfortably laying under the bus.

Oh, and please don't forget to block the car and put it in neutral. You don't want to accidentally jump the starter and run yourself over! Double check this twice!

[BusBerd]

Update: I think I found it.

The radio was wired incorrectly. I was able to play the radio even with all of the fuses out AND the inline power fuse going to the radio out. I found that the yellow wire for the radio "memory" was linked with the power wire after the fuse. When I disconnected every thing: no spark at the neg terminal on the battery! I wish I could blame this on the PO, but I must own-up to my own stupid screw-ups and learn from my mistakes. yes, I put the radio in.
So I rewired it and hopefully now it will not drain the battery.

I did check the alternator and on my multimeter i got 12v from the battery when not running and 13.6 volts while the engine was running. i could not get a good reading without using the negative terminal on the battery as a ground, however. Does that matter? are these readings still valid?

[Adventurewagen]

Update: I think I found it.

The radio was wired incorrectly. I was able to play the radio even with all of the fuses out AND the inline power fuse going to the radio out. I found that the yellow wire for the radio "memory" was linked with the power wire after the fuse. When I disconnected every thing: no spark at the neg terminal on the battery!

Might also try the radio with the power and key out to see if thats it. sometimes people run the yellow wire and the red wire to keyed power and permanent power and that could be the issue.

Man, I must be on today or my ESP is working. I'd be interested if this works.

But what it sounds like is with the radio disconnected now you get no more spark at all. Still seems though like the radio would need along time to drain the battery if it was off. Hope this works out.

[Amskeptic]

I think I found it.

The radio was wired incorrectly.
I must own-up to my own stupid screw-ups and learn from my mistakes. yes,

We all have to own up. And read Adventurewagen's posts carefully
Stupid screw ups are a pretty good way to learn. . . something about embarrassment burns the lesson into our neurons.
Colin