[My325iE90]

I know my subject seems weird, but I just bought a used 06 325i.

It was working fine when the guy sold it to me, but he brought me the car running. After signing the papers I go to my car and turn it on and I see all the Navigation system does is reset itself. It gets to the BMW splash screen, tries to start and then reboots.

Here is the thing, If I drive it with the AC running (or sit in parked with the AC running), in about 10 minutes the Navi system boots up and all is working normal. I can then do a long 2-3 hour drive and the systems works perfectly. BUT if I stop for even 1 minute and shut off the car, the system hangs again and only comes back on after running the AC.


I've read other threads here with the system rebooting, but that seemed to be while driving it would reboot itself. Mine is fine once it starts, it's just getting it to start that is a problem.

I also tried with NO AC, both just sitting in the car and driving it, but the system never restarts. ONLY if i turn on the AC. I'm guessing it's some secondary effect the AC is causing. Once the Navi starts, I can turn off the AC and it will continue working normally.

I also tried the 3 button reset like 10000 times and have also disconnected the battery for 10 minutes to reset.

I will say another thing, I had an indy shop with BMW diagnostic tools look at it and they said the code they were getting was saying there was lack of power at the CCC. I didn't find out about the whole AC thing until after. They also told me I need to replace the CCC. While I'm not saying they are wrong, I want to check out all my other options before doing that. I am also living in Spain which makes it harder and more expensive to get these parts here in the 2nd hand market.

Any thoughts greatly appreciated on what could be causing this,
thanks all!