Radio Fuse #72 Keeps Blowing ***FIXED***

[Lexicon740iL]

I had my cd changer magazine jam on me yesterday so I disassembled the unit and repaired it. Testing for functionality while un jamming and hot swapping the changer into the system several times.

So I fix the unit and button it back up and go to turn on my nav and I get no red light. I check the 30A fuse in the trunk and it's blown. I replace it and it snaps instantly. I meter the holder and it has 12.6V

I removed all fuses in the trunk for changer/radio/monitor and number 7 in the glove box for the monitor and disconnected the cd changer itself to try and isolate.
I get voltage at the 30A holder number 72 and voltage at the cd changer holder number 75 as well. Both in the trunk.

Any ideas? Did I freak something out when I hot swapped the changer into the BUS ? While testing/repairing.

Will a battery disconnect/ system get the ghost out of the system?

The 300LBS of equiptment on the trunk floor has stopped me from trying it already..

Any input is appreciated. TIA

[TerminatorX5]

something is shorted... what number is 30A fuse?

[Lexicon740iL]

Hi Term.

Fuse # 72 is the 30A for the radio
and Fuse # 75 is for the changer.

Both have battery voltage constant.

I did tap into the power harness at the changer and added a molex plug for tapping into the ibus for coding...

But I checked and the connections are all good. Soldered and shrunk. And the CD changer was functioning before I removed the fusing so I can't see how a short there would be present.

[bcredliner]

I agree with Term, you have a short most likely connected the work you just did.

Disconnect all power to the CD changer.
Put all else back the way it was, include removing molex plug and splicing wires to original
Replace fuses one at a time.
See if the problem goes away.
If not, check again that all of your work has been reversed to the way it was, if show it is something else
If all is OK, plug in the CD player to see if fuse blows.
If fuse blows disconnect CD player and connect molex plug to see if fuse(s) blows
If all is OK, wire in the molex plug to see if fuse(s) blows.
If fuse blows, the molex plug is bad or is wired wrong or the power wires are touching.
When you are 'done' the problem is gone, or, it is something else--just a coincidence, or, your work has caused a problem elsewhere.

[TerminatorX5]

check WDS for the fuse 72, i wil llook it up once i am home... a blown fuse always has one explanation - sharp increase in amperage through the circuit, which is consistent with a short circuit. sometimes simple, slow routing of the cables, methodical installation can resolve the short circuit... i had a TV harness that i installed in a rush, just to make sure that the TV module was recognised by the system... kept blowing one of the radio fuses... until i slowly routed the cable, and the short was gone...

you had some work done in the area and that is a clear give away... just retrace your footsteps there...

[Lexicon740iL]

Update............

Still no joy

I have Battery voltage at fuse holder 72 in trunk

WHAT IS THIS CONNECTED TO SPECIFICALLY?

I have removed my Car audio gear.
Disconnected battery of 1hr.
Replaced all fuses w/ proper amperage
Reconnect battery
SNAP.....30A Fuse in holder 72 snaps.

I hear my changer cycle/Nav drive read/widescreen illuminates

I pulled the wiring at the changer and inspected it well. I get voltage at the fuse holder with or without the changer plugged in so I know the short is not internal to the changer.

I checked the Molex plug I added to the 3 pin changer power harness... No short, it OHMS out fine. I have voltage at the Ibus wire, Neither Ibus or 12V+ are shorted. I also tested at the pins on the 3 pin cd power harness same thing. (I also inspected the 4 pin connection into the changer looks fine no breaks...Not sure what this connector contains)

* I connected my remote 12V+ feed for my aftermarket amp to the Purple/White Stripe in the harness to the radio module. So I removed the plastic cover by the battery and inspected this as well. Looks clean soldered and shrink wrapped just like I left it. I also removed the harness for the radio module to make sure I didn't have an internal short in the module itself. Same condition 12.8V at the # 72 fuse holder with or without it plugged in.

What am I missing? The radio designation in the trunk holder encompasses several fuse holders. But 72 is always my prob.

I have tested and inspected the cd changer wiring.
(What I was messing with before it stopped working)

I checked the wiring into the radio module where I tapped into for my remote amp turn on lead.

The only other mod into stock wiring was tapping into the stock amps subwoofer output wiring over on the right side of the trunk to input a signal into my line output converter. I have checked this as well and disconnect my Audio Control LC2i. All wires are clean soldered and shrunk wrapped.

I've tried to outline as much ad possible here guys If you have any recommendations it would be much appreciated. I don't know if I could bring myself to take her in for something silly like this I caused.

***On a positive note I had battery voltage at the 5A Fuse fuse holder for the CD changer previously but after disconnecting the battery and replacing the fuse that seems to have rectified that issue. It didn't blow again like the the 30A and I cant get 12V off the legs any more.

I love BMW's, 12v and car audio and it's really frustrating me I can't get this back in order.

[Lexicon740iL]

Is there a relay for the audio system that could be my culprit?

Relay and/or fuse causing flat battery [Archive] - CarAudioForum.com

[powers1]

Originally Posted by Lexicon740iL

Is there a relay for the audio system that could be my culprit?

Relay and/or fuse causing flat battery [Archive] - CarAudioForum.com

Does this help?See post #5
http://www.xoutpost.com/bmw-sav-foru...x-diagram.html

[Lexicon740iL]

Sweet! Thanks for posting that! Now I know where the audio relay is. Now how do I test it? Should I remove the relay. Reconnect battery and test for voltage at fuse holder 72 ? How do I test it on the bench?

[Lexicon740iL]

I pulled the Audio Relay and reconnected battery. I still have 12.7V at the fuse holder for number 72.......

HELP.............................................. ........

What is this circuit connected to? Which Loom should I be searching for a shorted wire?

I have disconnected, Radio Module, CD changer, DSP amp, audio system relay....

I still get voltage in fuse holder 72 for the 30A and it blows every time I try to insert a fuse.

I wish the Spaghetti coder site was still up.

Can u guys help me out please...... I can't bring myself to pay the dealer labor rate to chase a short.