Electrical problem ?!?

[munchkincoupe]

Had my Sony head-unit transferred from my A3 to the B6 Avant today. Installed at Audio centre, got into car turned ignition on and the fuel light came on and the fuel gauge read zero but the mileage hadn't altered from when I dropped it off with 1/2 tank.

Tech guy checked and a fuse had blown. Replaced it and the problem was solved. Went to drive away and the car died and refused to start - seemed like immobiliser - would turn over and battery was strong. Tech guys pushed the car back into workshop.

2 hours later and some time on the diagnostic machine borrowed from garage next door showed 18057 data bus power train and 01312 data bus drive - both these faults cleared when original head-unit back in and car then started no problems. Sony headunit then put back in and starts no problem but front speakers aren't working now

Tech guys said it is strange as the fuse that had blown didn't go to fuel gauge it was for the brake lights. When they removed the fuse the brake lights continued to work no problem?!?

Can anyone shed some light on what the problem may be?

Only fault I can find on the car is that the rear washer doesn't work. The one in my A3 split last year in drivers footwell and I repaired that. I've looked for obvious water sign in the car and bootlid but can't see any signs of fluid

 

[saxonblue]

i have had probs with head units in the past.... i got a fancy thing with bluetooth and dvd fitted by a local audio centre, it was never the same again,
cost me loads to put right and still stuffed the elecys in the end, better sticking to you oem one

 

[munchkincoupe]

I'll take it back to tem on monday to see if they can rectify it - if not may have to go with more standard headunit and get a Parrot instead

this is the headunit Sony DSX S300BT with the ipod tune tray - DSX-S300BTX (DSXS300BTX, DSXS300BTX.EUR) : Portable audio : Sony