CR220 Blue Antenna and Amp Wires

[RandalJ]

I have a '99 "HiFi" equipped 996 and I'm confused about two things in the CR220 radio manual's connection diagram. Could not find this specific topic in the archives.

Looks as though socket A, pin 5 is "control output for automatic aerial/amplifier". But socket C1 pin 6 is also "control ouput for automatic aerial/amplifier".

Is one of these actually referring to the power amp, and one to the antenna amp?

I know that C1 is only used if the car is HiFi-equipped, so I'm thinking that logically C1 pin 6 would power on the Amp, rather than socket A pin 5.

Then there are the antenna power connections on this same pins. It would make sense to have the same antenna power connection for both HiFi and non-HiFi, therefore that connection should be be on socket A pin 5. So what's up with having it on C1 which only exists if you have HiFi?

Anyway, how should I connect up to an aftermarket head unit that has just one lead (blue/white) remote power for the power amp, and one lead (solid blue) for the power antenna? Blue/white to C1 lead 6, and solid blue to socket A lead 5?

Thanks in advance.

[Loren]

According to the schematic...

C1 pin 6 is switched power for the amp.

A pin 5 is the antenna amplifier connector.

The is no power antenna line.

[RandalJ]

Thanks Loren. I did hook up the C1 pin 6 to the power amp ("remote") turn-on wire of the head unit, and initially left A pin 5 disconnected to see what I would get. Everything powered up OK but no sound. I then touched to A pin 5 wire to the connection above and got sound, so I connected A pin 5 to C1 pin 6, and connected these to the remote turn-on of the head unit, and everything works with no static on the radio, except for mild static on AM if the station is weak.

I do want to mention for anyone wondering that I was able to install the head unit (a Nakamichi CD400) without cutting any of the factory connectors (the A, C1 or the antenna cable) off. This should be the case for any aftermarket head unit.

You can get every connector you need to connect to the factory harnesses by ordering this:

http://enfigcarstereo.com/shopsite_sc/stor...RA_70_1787.html

The red connector connects to the C1 connector in the car for lines out to the power amp. I looked all over, and was almost resigned to cutting C1 off or tapping into it before I finally found this.

The black connector connects to the black A connector for power and ground. This one is pretty easy to find.

None of the web merchants I visited seem to realize that these Audi/VW connectors also work for early Boxter/996 with conventional wiring.

You might also need this stub antenna adaptor (female to male):

http://enfigcarstereo.com/shopsite_sc/stor...ml/40_VW12.html

Cable version works too, but I wanted to minimize clutter.

[RandalJ]

One more important follow-up note on using the Metra 70-1787 adaptors. For some reason the A socket connector came to me with A3 and A5 connections (both blue wires) bridged with another blue wire. Maybe this has some purpose for Audi and VW. But you use it as is on your Porsche, you will drain your battery in a matter of days. I've been troubleshooting this this week and finally discovered that blue bridge wire must be removed or else you will have a constant on signal sent to your factory amp, and you'll be draining hundreds on milliamps from your battery (I believe that normally it should be below 30mA or so with ignition off).

As to why connecting A3 to A5 (regardless of whether these are connected to the head unit) causes the power amp to be on when the ignition is off, I'm still not sure.

Otherwise, these adaptors are a perfect fit for our Becker factory harnesses. No need to cut the sockets off!