Hey, I'm an apprentice mechanic but I can't figure out whats wrong due to lack of equipment. Basically my cars stereo will only turn on if you have the volume at max, and you have to drive for about 5-10 minutes before it comes on, sometimes it doesn't come on at all. When it does come on, it fades away if you stop at a set of lights. The car is a 1989 BMW 535is, and it has had an aftermarket alpine unit fitted to it, I'm not sure what the model is, as it was installed by a previous owner. I was thinking it might be an alternator issue, but my battery hasn't been losing any charge.
Country: AustraliaMake: BMWModel: 535iSYear: 1989Engine: 3430cc Straight 6
Tested battery for charge, charge rate seems fine, battery is in good condition.
Hello, thank you for choosing Just Answer. My name is XXXXX XXXXX X will help with your BMW radio problem.From your description, I am confident that the fault is in the aftermarket radio. I suspect that if you remove the unit and test for power to it, you will have a good 12V signal even when the radio is not working. That test will rule out any problems with the car's electrical system causing the radio not to function.Because the volume level impacts function, you can condemn the Alpine radio. Buy another head unit, install it, and your problems will be solved.I hope my answer is helpful. Let me know if you have any additional questions.Best Regards,Stephen
5+ years experience managing an import repair shop specializing in German vehicles.