Tested the sensor and was not getting any reading, so I replaced it. It was very tough to get in there and I am not sure if I had a good connection, but that did not solve the problem. Still getting code P0502 -- speed sensor circuit A low voltage.
I tried clearing the code while driving, and everything went wonky. It must have been compensating for not having the signal, and I disrupted it. Pulled over and restarted and it ran fine again, but still no speedo and still has the code. the speedometer does flicker to life every so often for a split second.
I still suspect the wiring due to the slight fluctuation of the speedo needle every now and then, but things are very tight in there and I can't really get a good test. And am I just checking the resistance of the wires?
What should I proceed to check from here?