Bought a 94 s10 blazer that had an aftermarket radio, decided to replace with a different one and found this mess. I bought a metra 70-1858 to replace the factory plug, but I'm uncertain about the red and black wires circled (as well as the ones a little above them), they run down to the center console in the loom with the cigarette lighter (pic 2). I'm thinking it was something aftermarket because the part with the cigarette lighter has 3 holes instead of just one but was wondering if anyone might have an idea?



The previous owners ran new front speaker wires but left cutoff ones in the area, are the green/light green wires the factory colored speaker wires? I'm wanting to return the wiring as close to factory as I can.

 

I think what you are looking for is this:

 

It seems that the additional black and the red wire are not OEM. In that loom should be 1 black for the radio ground as per schematics.

You probably need to follow these two wires all throug.
Black wire - As they are already cut i would check for voltage, then (if no voltage!) or battery disconnected for continuity to ground (any ground connection on the body) to figure if it is a ground.
Red wire - more difficult. I do not want to advise on how to search for such a wire in a mess. If possible follow it and see if there is a connector, where you can measure for continuity with the cut end, then continue from there.

Only red wire i can find in the schematics is from the fuse block to - under dash left of steering wheel to a fuse holder (10 A) for the parcel tray's power outlet.
I'd definitively follow these wires. Maybe previous owner had that fuse blown and unable to find it wired it directly to somewhere else.

 

Thanks for the diagrams! They match how I wired up the harness. Also the red/blacks are definitely aftermarket, given the size of the holes in the lower console and that they were spliced into front speaker wires I think someone tried to install tweeters. I'm going to undo the loom and remove them and re wrap it.

 

@error_401
While I'm waiting on my chiltons manual, do you happen to have a wiring diagram for the digital gauges? I found two white wires down by the OBD port (dont't go to the port) that I traced back to a pair of white/orange wires that join a big bundle of wires right behind the heat/ac controls but I can't trace past there for now.

 

The Chilton are o.k. for servicing. Will be interesting to see if the schematics show enough details.

I have the factory service manuals (all three of them) in paper form.
At some time they were available also in electronic form (PDF i believe)

https://www.rockauto.com/en/catalog/...r+manual,10335

It'll be a while until I have access to my manuals, as I'm not at home.

 

Right after I responded I found those manuals and ordered them. They're very helpful but a little overwhelming. Chasing some other issues so will come back to wiring when I have the truck driving without issue. Thank you for al your help!