speedometer

Hello

Well after replacing the head gasket and putting everything back together, all of a sudden the speedometer and odometer are not moving.

some one came and did a diagnostic check at my house (i wasn't here to watch) because the check engine light came back on and he said nothing is wrong just change the oil and flush the engine (still had water in oil). I started it up the check engine light went out, had it flushed and oil changed 3 times and while driving back that light came back on.

Some say they know someone whos light has been coming on and off for years and nothing is wrong............ well, i went to get it smogged and it failed due to the VSS vehicle speed sensor and check engine light. i removed the EFI fuse which reset the computer and now the light is off but speed/odmeter still off.

Is the sensor underneath at the back of the transmission or on top of it or in front of it and is there a cable as well that may have come loose?

I have a Haynes repair book but i can't figure out exactly where it is and the guys that have helped me are playing stupid and don't think i know what i am talking about. What's to know except that they worked prior to the removal of the head but i'm unsure if they worked after head was replaced (i didn't look at the spedometer as i test drove it to end of the block) and if they did work after head replaced, could the guy with the diagnostic meter have done something to cause them to malfunction?

I appreciate any advice and suggestions because i think the sensor just isn't plugged in tight or the cable is loose (if there is one) or some type of loose connection to it.

Thank you
Karena