New stereo drains battery
 

I just bought a '88 626 in excellent condition. It had a factory-fitted radio+cassette unit that I have replaced with a new Pioneer CD player.

Since I have no manual for the electrical system, I resorted to just using a multimeter to figure out the connections. I got it all working nicely last night, and went to bed. Got up this morning, and the engine wouldn't turn over - battery didn't have enough left in it. Not a major issue, starting with jumpers from a spare battery did the trick, and all is well again, but clearly I've done something wrong with the wiring, so I need some help.

Power seems to come in from a 1-pin connector. The "accessory" power comes from one of the pins on a green 3-pin connector. One of the other pins on this connector seems to be for lights (tied to the headlight control) which the Pioneer unit has no support for, so I tied it off. I was unable to determine what the third was for.

One thing I noted was that when the ignition was turned off (ie turned to "lock"), the accessory line drops from 12v to around 3v, which was not what I was expecting.

So, I suspect the problem is either to do with the mystery third pin on the green power connector, or the odd voltage on the accessory line.

Does anyone have any ideas, or know where I can get documentation for this part of the electrical system?

Cheers.

RE: New stereo drains battery
 

Here is the diagram that I have, had to post in two parts.

[IMG]local://upfiles/1828/5AF6B45F1F9B487E9E043F4BC62624D8.jpg[/IMG]

[IMG]local://upfiles/1828/88C89C9D1D7946CF9923E5F4765A6F50.jpg[/IMG]

RE: New stereo drains battery
 

rob, I will post some info with the wiring locations and wire colors tomorrow when I can get back to the factory diagrams for audio system.