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Old 11-06-2011, 01:14 AM
seemyad's Avatar
seemyad seemyad is offline
BMW ****ie
Location: Seattle WA
Join Date: Jul 2011
Posts: 1,324
Mein Auto: 530i Sport Package
Yet another twist.

Pins 15 and 17 (head unit left front output) in my car feed the RIGHT/front woofer. Three diagrams I studied suggest these two pins feed the LEFT/front woofer..

I believe the wiring diagram posted above in this thread is correct as it agrees with the one I used to install my subwoofer a month or two ago.

HOWEVER, my head unit's front left and right channels are BACKWARDS aka swapped!

Friday I spent half the day troubleshooting my new amp install. I faded and balanced my radio to front/right to test my first connection and got nothing from pins 14 and 16. I restudied two different, yet in agreement, wiring diagrams and thought I had a bad amp or bad connection. I stripped back the front right woofer wire pairs to ensure a good connection and still nothing. I tapped into the rear right input and the amp worked so I still thought I had a bad connection.

I removed and dismantled the 26 pin connector. I used a twist-tie that I stripped and connected to my amp to probe each pin (holes were too small to fit anything but a sowing needle or a twist-tie that sometimes is used to close plastic bread bags and such). That is when I discovered that when the fader/balance are moved to the front/right pins 15 and 17 (head unit front/left outputs) are hot and the opposite was true as well. YET, the speakers would react correctly to shifting the balance between left and right (odd). So I tapped into the head unit's LEFT channel output to run the new anp that I connected to the front right door woofer and it worked.

Every diagram shows the same left/front right/front color code and pin-out. My connector color code and pin-out agrees with the diagrams however the front left and front right channels are swapped elsewhere (I suspect at the connector on head unit itself). My rear channels may or may NOT swapped. A month or so ago I bridged the subwoofer amp (I installed) output from the rear channels so I really do not know if they are backwards too (and don't care at the moment). Due to the subwoofer amp being bridged shifting the balance left or right produces the same outcome with the sub so I cannot truly say the rear channels are not backwards as well.

Weird. Just weird and very taxing to troubleshoot when you justifiably trust the diagram which agrees 100% with other diagrams.

Last edited by seemyad; 11-06-2011 at 01:12 PM.
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