My speedometer doesn't work, I am going through the system in an attempt to find out why. Does anyone know where the speedometer cable gets it's signal from in the engine compartment (or wherever it may be). This is a 79 full size with an automatic transmission and no cruise control.

 

It's connects to the transfer case, not sure what side, assuming you have an NP203, it's on the right side facing the rear. the end of the cable has a kind of square part and a threaded cap that goes around it, which threads onto the spot on the transfer case. i have a 73 blazer with a similar problem, but my problem is that i put an NP205 in it and the spot where the speedo cable connects is on the other side, making my speedo cable to short :/ lol. i just gauge it by what gear i'm in and what RPM's i'm runnin at. hope i could help!