Monday, December 12, 2011

Becker Radio Install - Day 1

Maybe its the Jag blood in me, but ever since I got my 560, I've wanted to turn it into a 10 point Concours car. One of the most important things to do first is to restore the car to original specification.

When I got my 560, in the place of the beautiful Becker unit, I found a nasty looking Sony radio that only played through the driver's side door speaker. This had to go! I quickly sourced a Becker 1480 and the Becker amps from a parts car including the wire harness and decided to install it slowly during the winter.

Today I started the project by removing the Sony deck. Remove the ash tray and push from behind, is what everyone said. Of course its never that simple. The Sony radio had a trim ring that needed to be removed first, which exposed the DIN mounting cage. You are now meant to insert some sort of Radio removal key into the slots and pull the radio out. Obviously I don't have any Sony radio removal keys. Therefore I used a butter knife and depressed the metal locking clips and slid the radio out.

Now onto the DIN cage. The bastard that installed it into the car had glued it into the console. Again, using my trusty knife, I managed to cut it out without damaging anything.

I tested the Becker radio on a bench using an old computer power supply and speaker. It worked beautifully. Fantastic FM reception. Even in the basement it picked up more channels than I even knew existed.

To my amazement the original wiring harness hadn't been completely gutted. And it didn't look like it had been modified except for a spliced ground connector. However, something was missing. According to the workshop manual, the rear 3-way speakers and the door speakers are driven by two independent Becker amplifiers. One for the left set and one for the right set. Now usually the dash or door speakers are driven directly by the radio. This setup is very similar to all the other 80s Mercs, and I know what the little speaker connectors that plug directly into the back of the radio look like, but I couldn't see any in my 560. The diagram in the manual makes it seem like all the speakers are driven by amps. Maybe Mercedes just left the speaker connectors on the back of the radio for other models?

To my horror I found the powered outputs from the old Sony deck had been connected directly into the line input for the Becker amps! Ahh! This could explain why I can't hear anything from the other speakers - the original amps have all probably been burnt out. But then, why was the Sony radio playing through the driver's door speaker?

I removed the old radio and installed the Becker unit. Powered up, entered the code, and it looked like it was working. But I couldn't hear anything from anywhere.

I guess I'll need to pull the rear bench seats and investigate further. Not a very nice job to do with this car as its equipped with heating and reclining rear bench seats.