1998 Bose draining battery and static burst?

[landmarkjohn]

Hi from John and Bernie,

Having radio trouble since we got 1998 MK2 last October. I am pretty sure it is the factory Bose setup and it is draining the battery after a day or two. With the key in the off position it is still drawing 400 mA. I have fitted a switch to the 12V constant which fixes it, the only problem is when somebody forgets the switch and it is a pain retuning the radio every day.

A clue might be the burst of static through the speakers when the key is turned on (if my constant switch is in the on position). The previous owner did have a different head unit in and then swapped back original.


Any thoughts appreciated.

[franksm]

Hi John, Bernie

Try popping the head unit out and swapping around the red and the yellow wires. One provides permanent 12V, the other provides 12V only when the ignition is on. It's an ISO standard that some manufacturers have screwed up, so most looms come with a changeable connector for the red and the yellow wires, letting you fix it manually.

That's assuming your head unit is connected to the car's loom via a small interface loom. If your head unit is directly connected to the car then the problem is with the head unit (maybe this is why the previous owner added a different one, then put the original back when selling it to you). There may be a relay inside the headunit that is sticking, and causing the power drain.

Hope that helps

Frank