ABS Speed Sensor error

1991 S10 Blazer, 4.3 L engine

I'm getting an ANTILOCK error on the dash, the first error code says speed sensor.

Let me mention that I did extensive work on the driver's side front, as I had loaned my Blazer to my father-in-law, who got it into an accident, and I had to replace a lot of metal, including the fender. I had to mess with and unplug a number of wires. The ANTILOCK error code did not show up until after I had done my work. :(

Looking around for something I messed up, I found a connector with no wire in one side. This is a connector that is right on top of the brake vacuum booster, the driver's side of the connector is black and has a single black wire/white stripe coming out of it (I note that it looks the same as one of the wires going into the ABS module). The other side of the connector is brown, and is missing the wire going into it. I thought this might be a prime candidate for the error code, but I couldn't find a hanging wire anywhere, and I don't know where it goes to try to track it down from the other end. I can't find it in my Haynes manual.

Anybody got any thoughts?

You need a good wiring diagram on it.
Public libary.
Factory repair manual
All Data online sub,
http://www.alldata.com/products/diy/index.html
And sometimes AZ online site has some repair info .
I would also pull ABS codes and post back code no.
Good luck

Thanks, MT-2500, all good places to look. I was hoping for a quick one, though, as in if someone else had a 91 (or close to it) s-10 blazer they could take a quick peek under the hood and let me know what's on the other side of the connector. AZ doesn't have the info, neither does my Haynes, so I will have to try one of the other options.

I did dump the abs error codes, they were a 6 (speed sensor) then a 5 (rear dump valve, or something like that). I figure first fix the speed sensor problem and see if the other one is still there.