Interesting Electronic Issue

[nasco]

So since Friday Night I have noticed an interesting electrical issue on my 2002 540i. While I was listening to my music over BT via the Dice Mediabridge system I've had in my car since ownership (approximately 4 years prior to that with the PO), the radio suddenly turned off. I immediately turned it back on not thinking anything of it. That was the first time it had done that in my ownership of the car. Then I got home 4 minutes later, pulled my key out of the ignition and the speakers continued to play music for about 40 seconds, and then I thought oh this isn't the A6, why the hell is the music still playing.

Then I take a look at all of the fuses, I see fuse 58 is popped, put a new 10A Fuse in, turn the key, start playing music take the key out everything else shuts off (Fuel Pump, Interior Lights, and literally everything else) except for the speakers. Fuse 58 popped again, this time I turned off the radio, put the key in the ignition, fuse 58 pops again. I started by pulling the BMW Buisness CD system apart, I replaced the 10A Mini Fuse in the back of the CD player, and checked all of the wiring. I then pulled all of the fuses related to the Radio, On-Board Monitor and MID. So 25, 43, 44, 56,& 58. I came to the conclusion that If Fuse 43 and 58 are in at the same time, 58 automatically pops if the ignition is activated. 25, 44, and 56 have no effect. However the issue with the music continues if I have Fuse 58 in, but 43 out. I checked Fuse 58 and I noticed it's hot regardless of ignition position, but only pops if those two conditions are met.( Switching the ignition to any of the on positions with Fuse 43 in) I was not able to connect to the On-Board Monitor in INPA, but was able to connect to the DSP AMP, Radio, and MID. No errors in their memory.

I also completely unplugged the DSP amp in the rear, the radio and CD Player. Swapped the Radio with another one that I have laying around with several dead pixels and the Fuse would still pop.

I'm not sure what to check here/what the issue could be. I saw the issue of Fuse 58 popping only showed up one or two times on the forum prior, and the issue stopped at replacing Fuse 58.

Any and all Suggestions are greatly appreciated, as while this is a minor issue. I'd prefer this not be the preface to a major issue that sets this car on fire.

[nasco]

Bump

90 Something views and 0 Replies :/

Did a little more poking around today. Replaced the Overload Relay (K3) as well as every Fuse related to the Radio On Board Monitor, so on and so forth, issue went away on one start up. I accidentally removed fuse 56, the issue came back the next time I started the car. Re-did all of the above. Issue is still present. Fuse 58 Blows even if I have the Overload Relay Disconnected and Fuse 43 connected, which is interesting to say the least. I'm very much ready to just drive this off my nearest local cliff. Any ideas? Bad DSP amp? Bad General Module? Any additional Wiring I should check?

[Keith Nguyen]

What is fuse 43 related to?


--=Keith

[nasco]

Fuse 43 and Fuse 58 Connect to the Overload Relay. Fuse 43 is also a fuse for the Radio, Telephone (Which I don't Have), On Board Monitor, Navigation (Which I again don't have)

[Keith Nguyen]

Have you tried disconnecting the those components related to fuse 43 and see if the fuse still pops?


--=Keith

[nasco]

I have, minus the OBM bc I'm not 100% sure how to disconnect that. However, after doing some further diagnosis, I suspect that it is a failing GM3. Fortunately bc I have a 2003 530i with what appears to be a fully functioning one. I'm going to recode and see what's what. Will update shortly.