700r4 electric speedo question

[DrtyJack75]

So I had a guy put a 700r4 in my truck and the other day when driving it around the block, the speedo wont work....

Didnt have time to jack it up and investigate more but Im assuming he didnt wire it up.

I reached up the truck and this is the picture I could get.....

my question is what is the black plug just aft of the tranny cross member?

and where should the electric speedo be plugged in?

[usmcchevy]

That black plug should be your Vehicle Speed Sensor (VSS) and it is where your speedo should get its signal from.

[gap1362]

That plug you need is still avail from GM you will need your #'s off your trans and it's a 2 wire install ,at least in my case with a dolphin speedo 1 wire to ground and 1 to feed it (hot)

[stich626]

you also may need the buffer, g.m. put inline