armoredraven3

Hey guys,

So I've had battery problems with my 2007 V6 Mustang for a long time now. For as long as I can remember now, I've been disconnecting the battery whenever I am planning on letting the car sit for more than a day. I've gone through at least 3 batteries now, and nothing is really changing.

So I finally got around to getting a multimeter to try to see if I could identify a battery drain myself. Here's how I set it up on the battery, just to make sure I'm doing the testing in an appropriate manner:
Connected black cable to multimeter COM port, red cable to 10A port.
Set multimeter to 10A setting (highest amp reading setting)
Disconnected negative battery cable from post
Complete battery circuit by connecting red cable to battery cable and black cable to battery post
(I'm pretty new to this, so just lemme know if I should be doing it in another way)

So I let the car sit for a while and checked the multi meter reading. After everything went to sleep, it settled just around 0.15A, so just around 150mA going through the battery. Pretty sure that is too high to be normal drain on the battery.

What I did was just check the fuse box and started yanking away until I could see a measurable drop. I removed each fuse/relay individually, but none seemed to drop the drain at all, except for one - fuse #68. If I'm correct, that's the fuse for the ignition, right? Removing that one gave me a stable drain of 20ish mA. None of the other connectors would give me any measurable drop at all.

So fuse 68 is connected to the ignition switch. I went about changing my mustang's ignition switch, figuring that the problem was something there not shutting the car off correctly. Got a replacement ignition switch at autozone and put it in pretty easily and it worked fine. Car started normally and what not.

Measuring the battery draw, however, I saw that there wasn't much of a change. I was still getting a consistent battery draw of 250mA which drops to 150mA after a while when the car goes to sleep. Still goes away when I pull fuse 68 for the ignition. So... ignition switch was not the problem.

Now what I did was disconnect the switch altogether, so all there is now is a hanging 6-wire red/black connector that is supposed to connect to the ignition switch. Even with it disconnected like this, I'm still getting the same consistent drain.

So now I'm stumped. I know there is a draw coming from fuse 68. Fuse 68 connects to the ignition switch (6 cables). Even when these cables are not connected to anything (the switch), there is a constant draw of 150+mA on the battery. What could this possibly mean? Where could the draw be coming from if nothing is connected to the ignition switch? What are my real options at this point?

Thanks for any help you can offer!

kevinmalec

I've read numerous post where individuals experienced battery drainage issues due to their shaker radio system. I am not sure if this is the case or not, but wanted to relay.

Nuke

These S197's are notorious for battery and alternator issues. And the parasitic current drain IS a bit higher than most other cars that I've seen. But 150 ma shouldn't kill a healthy automotive battery overnight. I suggest that you have the alternator AND battery load tested. One being bad will degrade the other; quite a common occurence on our S197's. Toss in an OE battery that's garbage (not called MotorCrap for nothing) and you have the makings for problems. And if you're making a lot of short trips, that also has negative impact on the charging system.

armoredraven3

Thanks for the replies.

Regarding the radio, I do not have the shaker 500 system that has caused widespread battery drain among S197 mustangs. Pulling the radio fuse altogether doesn't seem to decrease the battery drain at that.

And I just had my alternator changed, thinking that was the problem, but there is still that consistent 150mA battery draw. I know that isn't enough to kill the battery overnight, but it is still very annoying and out of the ordinary.

So yeah, I'm still stumped :/

tx_zstang

There's things that stay partly-powered on the entire time, including PCM, SJB, anti-theft, etc. But you've already taken care of the #1 issue, that being the shaker radio; did you remove or disconnect the amplifiers, too, or are those still hooked-up as stock?

As far as fuses, there's those in the SJB as well, if you're really trying to find all power usage.

wayne613

http://iihs.net/fsm/?dir=40&viewfile...%20Cluster.pdf

http://iihs.net/fsm/?dir=40&viewfile...bution-SJB.pdf (page 3)

Afraid you've still got the instrument cluster, which then powers some things, transmission shift selector, etc..

As stated, start pullin' SJB fuses to try and lock it down further.

armoredraven3

Thanks for those wiring diagrams! I had actually already gone through each fuse in the SJB as well when I was trying to track the draw; none of them contributed any major draw at all.

Here's what I'm looking at now. Looking at the second diagram (pg3), the fuse giving me problems (F.68) is connected to the ignition switch (Already replaced switch and that wasn't the problem). What's strange is that I still get the batter draw when the ignition switch is completely disconnected, i.e. those 6 wires are not connected to or powering anything.

This leads me to believe something is going on with the fuse in between switch and fuse box BEC. Looking at the fuse diagram for 68, there only seems to be one thing (that arrow looking object) in the fuse circuit that is labeled C210/D4. Could someone please explain to me exactly what that is or how to interpret the diagram? Is it some sort of relay or connector?

Highlighted it here:


Thanks a bunch!

wayne613

http://iihs.net/fsm/?dir=40&viewfile=Symbols.pdf

Just a connector. Have any after-market items that might be spliced into this line? The draw should be less than 50mA.

armoredraven3

Thanks! I actually found a diagram for the connector here: http://mygtcs.com/mustang/documents/...210-Inline.pdf

What I'm planning on doing now is disconnecting cable 1050 at D4 (connected to fuse 68 with my drain) before it goes into the C210 connector to see if the connector could possibly be the issue, or if it might be with the wiring in between the BEC and C210 connector.

Does anyone know where this C210 inline connector can be accessed? Someone said it's behind the right kick panel, so it may be right next to the SJB?

Any tips/ suggestions would be great!