Swap alpine amp with Lear
 

The Alpine HiFi amp on my 2005 x5 3.0i recently went out and I went to a junkyard today to find a new one. I ended up finding the Lear E39/E53 DSP amp along with the sub that comes with that model. I tried to put it into my car only to find that the Alpine amp connection is not the same as the Lear.

Further into the trunk under the spare I did find the 2 connectors that fit into the Lear amp. I hooked the amp up and did not get any audio out of any of my speakers, but instead the fasten seatbelt warning kept dinging and my air conditioning came out hot. I disconnected the amp and everything went back to normal. I also did not find any cable to hook up the sub

I have an aftermarket stereo that my buddy installed and that may be the reason why the speakers did not work but I am not entirely sure. The stereo was put in after the amp had blown (when I brought my car to the audio shop the guy said there was no amp in my car and the stereo needed to be replaced) and he may have not installed it correctly.

Is there any easy way to connect this amp to the car? And is there any way I can hook up the sub as well? I was thinking if BMW took the time to put the amp connection in there would be an easy way to hook up this amp and most likely the sub

I replaced the Alpine amp in my '06 non-DSP 3.0 a year or so ago. I am running an aftermarket Android head unit made for the E53. It works with my Alpine amp.

I was surprised to see the original Alpine Amp installed at the factory in '06 was made in China. I didn't think BMW was using many Chinese-sourced parts in the factory in '06...

Anyway I was able to find a new old-stock original Alpine amp on Ebay for relatively short money.

I don't think you can simply plug in a DSP amp into a non-DSP car...I can't explain exactly why other than I think the DSP system is coded into one or more modules.

So I did some more research and it appears that you are right. The DSP amp only has 2 channel inputs while the HiFi amp has 4 channel inputs. I'm still not sure why there is a hookup in the car for the DSP amp or why when I hooked up the DSP amp my electronics starting going wonky. Maybe it has something to do with the IBUS connection.

The DSP amp requires a turn on signal over the ibus from the MID or board monitor. Without that signal, you won't get any sound.

The harnesses for these cars were produced "fully optioned". Easier to deal with one harness part during manufacturing than a new harness for all of the different options BMW offered.