help, puzzled by the radio connector

[Bean]

Hi everyone,

although I like the sound of our engines and it's all I need on a fun drive... there are times I'd like to have a radio.

I looked at the connectors and the schematics for quiet some time and I'm able to connect the new radio but there's still something strange about the wiring



In the bove pic you can see two connectors:
the small on the left is permanent power (+12V fused by 10A in the engine bay)
the blue one is the main connector, the 4 pins on the left side are the two front speakers, the pin on top on the right side is switched (ACC) power (+12V fused by 7.5A in the kick panel) - the two on the bottom are both grounds

the last part is where I'm lost - the wiring schematics in the manual doesn't mention 2 grounding wires, just one.

I wonder if something with my wiring is off, although I'm pretty sure it's genuine as I used to have an original radio in there at one point (wish I still had it). Can anyone verify my findings or knows the reason for the strange fact of two grounding wires?

Thanks in advance Bean

[Ivan141]

By the looks of things you just have a bonus ground wire there (bottom right pin in your pic)..
If you look up that connector in any manual I know of it will be missing that pin (as you said).
I did notice the pin numbering in the electrics manual skips a pin number (nr4).. perhaps that is your bonus pin.

[oldeskewltoy]

Check out the wiring manual.... it appears that you have an extra wire in your blue connector.... at least that is based on the 1986 USDM wiring manual (section 24, page 56-57)

The blue connector in the manual does not show a wire in the lower right slot(#9). The top three appear to be right, and the first three on the bottom appear to be right.

#1 = upper left in plug - LG wire color and goes to the rt front speaker #1 (of 2 connectors on speaker)
#2 = next to #1 - P wire color, and goes to lf front speaker #1 connector
#3 = still top row, other side of clip, GR is wire color comes from radio fuse No2(7.5 amp)
#5 = bottom left in plug, L is wire color and goes to #2 on rt front speaker
#6 = bottom row 2nd from left, V is wire color, goes to #2 on LH front speaker
#7 = bottom middle, W-B is wire color, goes to ground

There is no #9 in the USDM manual

You should also have a black plug, a bit smaller (5 wires instead of 9) those would be the rear speakers, and radio fuse #1 (10 amp)

[Bean]

which manual you refering to, as the general one doesn't show this pin

EDIT: found it, no black plug for us in the EU Dan only had front speakers at least on the hatchbacks.

still kind of puzzled why it's there, maybe someone did mess about with the wiring at one point.

Thank you both

[banpei]

In my AE86 I did have the extra black plug and even though it used to be a SR5 the actual SR5 was replaced for an EU loom.
BTW, this should be a good resource for the radio wiring:
http://www.installdr.com/Harnesses/Toyota-Wiring.pdf
It specifically says do not use for the extra ground.

Maybe someone needed the additional ground for a reason and thought since this wire normally would not be used it would be a good fit?