QuestionHi- I found a similar answer here on the 'net about VW amplifiers. Mine question is a bit different. I think my amp is starting to die, it's been draining my battery when the car sits a few days. I understand that this particular amp is pretty specialized and I've been told that my speakers (8 factory) may not even work with another Amp. Firstly, does this "diagnosis" make sense, that it can drain a battery over 4-5 days of non-use (no other accessories "on"). Secondly, is my problem as simple as going to Best Buy and buying an aftermarket amp? If not, can I buy a new head unit that will run my current speakers?
I'm the original owner of the car and I do sometimes notice a "boom" when I turn the stereo on or off.
Sincere THANKS!
AnswerHi Jeffrey,
As far as I can tell, your Jetta's Bose amplifer is a fairly basic setup (for an OEM amplifier). Despite the 8-speaker system, the amplifier has only four channels of output; each channel runs a woofer/tweeter set in a door.
There's nothing about the speakers that makes them incompatible with an after-market amplifier, although they may not be suitable to connect directly to an after-market head unit. Bose systems often use a 2-ohm speaker; this isn't generally a problem with an after-market amp, but it's not a good idea to use a head unit with speakers rated below 4 ohms. So a typical 4-channel amp should be effective as a replacement for the Bose amplifier, though there are a couple things to consider.
The factory head unit uses separate positive and negative signal leads for each channel, running between the deck and amplifier. These are likely to be low-level signals, and it's possible that they can be wired directly to the new amplifier's RCA inputs; however, there's a good chance that you'll need to use some sort of adapter module to make an after-market amp work effectively with the head unit's outputs. Also, it's highly likely that the Bose amplifier includes some built-in active equalization to get the most from the Bose speakers. An after-market amp won't have the built in EQ curve, so the sound quality may be quite a bit different from the original Bose amp. It's hard to say how much difference to expect, however.
It's certainly possible that the amplifier has an internal defect that's causing your power drain, but there's a way to be sure. According to my reference, the main power fuse for the amplifier is located in position #29 at the dash fuse panel; it should be a 15-amp fuse. You can remove the fuse, and use a multimeter's ammeter function to measure how much current is being drawn by the amp when the car's turned off. Anything over a few milliamps will confirm that there' a defect. (Otherwise, you can just pull the fuse and see if the battery drain issue persists).
Hope this helps!
Brian
