Red Wire at Battery - 2.3 Amp Drain - 82SC

[mtelliott]

Still trying to track down why I'm getting a 2.3 Amp current draw.

What I have done:
• Verified with a multimeter that I’m seeing a 2.3 amp current draw when connecting my probes between the positive lead and the positive battery post
• Pulled every fuse one at a time (no effect on the current draw)
• Pulled the alternator and disconnected: still seeing a 2.3 amp draw
• Disconnected the red wires from the positive leads and tested each individually
o Main thick lead – no current draw
o Red wire that splits into two wires – 2.3 amp draw
o Red wire (single) – 2.3 amp draw

So the questions are:
• Why am I getting a 2.3 amp draw out of the red wires?
• Where do the red wires go to?

Michael

[Hladun]

Two red wires seem to go to the ignition switch and one to the various lights. It's odd that both red wire circuits draw the same current. Is that what you're saying?

[mtelliott]

I was surprised as well to find that both wires have the same draw.

Anyone have any guesses on how to track this gremlin down?

[Hladun]

Just a guess, but Porsche's have the turn signal on while parked feature. Have you checked that?

[ZOA NOM]

remove all fuses and check for draw. if none, replace one at a time until draw returns. if draw is present with fuses removed, trace hot unfused wires to their destination.

[dmarv]

Did you pull the fuses in the engine compartment?

[mtelliott]

I removed the fuses one at a time (including engine compartment). I'm thinking from what I'm hearing everyone say that maybe I need to pull all fuses, then begin replacing one at a time.

Question:
If I pull all fuses and I still have current draw, what are the implications? Do the red wires run to anything directly (i.e. unfused)?

Michael

[dmarv]

My current flow diagram for a 82 model 911SC shows two red wires going to the ignition switch. The other goes to #18 fuse on the fuse panel, then it goes to the #10 pin on the main harness connector. From there it goes to the #30 pin on the Oxygen sensor relay. Hope that helps.

[dmarv]

Only circuit unfused is the ignition circuit, according to my diagram.

[dmarv]

I also show the wire that goes to the #18 fuse, has jumpers from the #18 power supply side (before the fuse) to #17 fuse, #19 fuse, and #20 fuse. 17 controls the hazard flasher. 17 has jumpers that feed power to power window relay, parking brake and seat belt warning light and horn relay. 19 fuses power supply to the head lamp washer relay (if equipped). 20 fuses power to the A/C relay and A/C cooling fan motor relay.

[ZOA NOM]

Ignition switch would be a likely culprit. Could be worn enough to leak a few amps.

[RoninLB]

some circuits are unfused.

2.3amps is a big drain. Even a bad unfused relay should only draw 400-600ma. The fresh air front flower is also unfused.

If one of the red wires from the battery terminal goes to the ignition sw main feed and it's drawing 2.3 then maybe I'd head in that direction.

Maybe toasted switch contacts feeding a circuit when in "off" position?

[RoninLB]

wild guess

2.3amps leads me to think the rear window heating element may be triggered.

[Hladun]

Originally posted by RoninLB
some circuits are unfused.

2.3amps is a big drain. Even a bad unfused relay should only draw 400-600ma. The fresh air front flower is also unfused.

If one of the red wires from the battery terminal goes to the ignition sw main feed and it's drawing 2.3 then maybe I'd head in that direction.

Maybe toasted switch contacts feeding a circuit when in "off" position?

2.3 amps isn't a big drain, it's 27 watts which is about what a turn signal or taillight bulb draws. You should see a circuit resistance of about 5 ohms.

[mtelliott]

Tonight, I'm going to pull some fuses and see what happens.

I'm wondering, my power windows work whether the key is on or not. I'm wondering if something could be going on with them pulling current. Previous owner did some strange things to the car. If like Hladun says that 2.3 amps isn't much, then maybe...

I'm also going to figure out where the red wires go to and see if I can't disconnect then and see what happens.

Ronin and Zoanas: I'm hoping your thoughts are not correct on a bad ingition switch. That would be a PITA to fix. Yes, it's in the book of 101 projects but still a PITA.

DMARV: Thanks for pointing out where the red wires go. That will give me a big head start tonight on where's it's hitting the fuse box. Most appreciated.

[ZOA NOM]

Yeah, it would be a PITA. It would make sense that the switch could be worn with use, but on the other hand, parts that get little use can corrode and fail, so it's a tossup. You'll know much more when you start attaching loads to the battery one at a time.

[911mot]

Do you have a stereo or amp that might be drawing current?
Also try pulling all the courtesy bulbs - glovebox , engine, trunk etc
Got anything plugged into the cig lighter?

[RoninLB]

Originally posted by Hladun
2.3 amps isn't a big drain, it's 27 watts which is about what a turn signal or taillight bulb draws.

The routine should be around 40-60ma for a proper system. 100ma is a noticable battery drain.

2,300ma is a big drain.

[Hladun]

Originally posted by RoninLB
The routine should be around 40-60ma for a proper system. 100ma is a noticable battery drain.

2,300ma is a big drain.

2.3 amps is about what a bulb draws, not a big drain by comparison to other electrical components such as motors. What are you talking about? If you're referring to what the current should be on a system that doesn't have a short then I agree with you. But mtelliott has already said he has a 2.3 amp drain.

[Joeaksa]

Might pull the 14 pin plug off of the engine in back just in case. Would eliminate one last variable if the fuses do not do anything.

JoeA