Hi all!

I am currently replacing the head unit in a 1990 Ford Econonline Van. I am having trouble getting the system up and running, which i believe is due to the wiring.

Not including the wires for 12v Batt, 12v Ignition and Ground, the head unit has wires coming out for Positive and Negative of both front and rear speakers (4 speakers, 8 wires), which goes into a new wiring harness to adapt to the stock connector.

The stock connector that i plug the wiring harness into (see attached image) has the following layout (from left to right per image):

Pin1 (Orange/Green) = Left front Positive
Pin2 (Black/White) = Left Front Negative?
Pin3 (Pink/Green) = Left Rear Positive
pin4 (EMPTY)
Pin5 (White/Green) = Right Front Positive
Pin6 (EMPTY)
Pin7 (Pink/Blue) = Right Rear Positive
Pin8 (EMPTY)

The new wiring harness i bought matches this pinout, aside from the three EMPTY's shown above are the remaining three negative wires.

When i plug the system in, the head unit turns on, i can scroll through radio stations or connect my iPod via Aux cable, however there is no sound.

Might be worth me noting that both the front right and front left speakers have a black/white wire attached to the negative. Perhaps these are both connected to pin 2?

The rear speakers have been rewired since it is a conversion van, so it has lost the wire color coding.

Questions:
Is this lack of sound due to the three disconnected negatives? Should i just connect those three negatives from the wiring harness directly to chassis ground? Or maybe to pin2? Or do i need to rewire all the speaker negatives into the wiring harness to connect up with the head unit?

Should i not expect the front left speaker to be working at least, since it has positive and negative attached already?

Any help would be appreciated!
Many thanks,
Ash

 

Looking at the schematics, your colors and tracers are correct as you ID'd them. Correct on the grounding of the speakers through the BK/W as well. Schematic shows all grounds spliced, and grounded into the connector BK/W.... I'd think the left speaker would be making noise as well. Who's audio unit are you adapting in?