How To: Key In Radio On Relay for Earlier ('75 and down) Buses

[vwwestyman]

In later Buses ('76 and up), it is simple to set things up so that you can turn your radio on simply by putting the key in the ignition switch.

In earlier Buses, it takes a little more finagling, and a simple relay.

This is all because of how the "You left your key in the ignition" buzzer is set up. In the later Buses, the a wire from the ignition switch sends a positive voltage signal to the buzzer, and this can be used to tell the radio to turn on. In earlier Buses, the wire sends a ground signal to the buzzer.

So we're using a relay to turn on positive power to the "turn on" wire of the radio.

Here is the wire and connector you need to find. The brown and blue wire is the ground wire from the ignition switch. The grey/black wire on the other side of the connector, presumably, goes to the buzzer.

(You could simply use one of those side by side wire taps but this is neater and will preserve the original wiring.)

I decided I was going to tie the ground side of the relay's coil to the original wiring. Connected to the relay is two wire pigtails, one with a male spade connector, and one with a female. This allows you to unplug the connector pictured above, and put the pigtails for the relay in between.

I have since put some heat shrink tubing on the male connector. You;ll see it in a subsequent pic.

Per the diagram below, I hooked up the radio's other wires. That yellow wire poking up was connected to the constant on supply in the Bus.

Once it was all hooked up, I used a square of double-sided foam tape to secure the relay to the air box. The black wire is not shown in my wiring diagram; I used a side by side connector to add the wire for the cigarette lighter.

Diagram I drew up:

_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing