This was originally posted on another MB forum (I'm new to the marque and didn't know where best to ask this) but it didn't get much traffic - thought I'd give this forum a go - so apologies if you've read it before. Hi, new person here, will try and convey all the info required but please bear with me. Paid to have the head unit from my last vehicle fitted to my new (to me) estate w204. It’s a CarPlay and DAB unit and since I had it hanging about after I sold my last car, and I missed the functionality, I thought why not. Looks great fitted, no problem there. First problem was the day after it was fitted I went out to the car and it had lost all the settings, took it back to the installers who informed me there’s a timed live in these cars and that’s why that was happening, goes off after 4 or 5 hours. No problem, they’ll run a permanent live from the battery to get around that. Next problem, head unit isn't losing the settings any more, but does restart after every stop/start cycle in economy mode. Which as you can imagine, is pretty frustrating. Harness adaptor company (Autoleads) recommend an in-line adaptor to force the head unit to ignore the drop in voltage during the engine crank. Bought that, fitted it, makes no difference. Spoke to another person at Autoleads who basically said “why did you buy that adaptor, that’ll never work”. Consistency issues with the technical staff there. Next up, a very much more expensive adaptor to hide the 12v drop during the engine crank, fitted that, makes no difference. So to clarify, in the original configuration the headunit would stay live during the day even with ignition off keeping the settings, was even happy during the start/top eco mode cycle, but it would lose settings overnight (or after a good few hours of non use). So a permanent live solution was to run a live from the battery. Only then did the start (of the start/stop eco cycle) affect the head unit. My question, and I can’t be the first person to ask it. Is there a permanent live in that head unit loom that doesn’t go to sleep, and also not affected by the engine start? It wasn’t affected when it was connected to the sleepy live you see. My options. - Find a real live that doesn't time out and is unaffected by the start/stop. - Have the vehicle modified to alter the start/stop - some reading of this forum seems to suggest that's either possible or completely impossible, I've yet to make my mind up. - The adaptor lead is supposed to mask drops up to 7v, and the Sony head unit is particularly sensitive to the voltage drop. Perhaps I have basically fitted a very expensive battery tester that is pointing out my battery is on the way out Thanks for reading, hope that all makes sense.