First, check all your fuses. Then check to see if there is voltage on the yellow wire, on the wiper motor, with the key on.
If the fuse is good, and you have 12v on the yellow wire, check to make sure the solid black wire next to the blue wire goes to a good ground.
If those things check out, try grounding the
other black wire(next to the yellow wire), or the light blue wire. If you have 12v on the yellow, and ground the light blue wire, the wipers should work. If they do not, the wiper motor is prolly bad. If the wipers DO work like that, then you have an issue with the wiper switch, or the wiring from it to the motor...unfortunately, the wiper switch on a '77 is on the turn signal stalk...not exactly the easiest thing to check, OR replace...
______________
Joel Adams
C3VR Lifetime Member #56 
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
