Wanted to update my original post about my 85 S10 Blazer rear window issue. After one year this is what I discovered through trial and error. The ground cable connection was corroded and the actuator would not function completely to allow the latch to disengage, cleaned the terminal and the actuator now functions correctly. I discovered this by disconnecting the actuator and connecting it directly to a battery charger, this provided a full 12 volts. At first I thought there was insufficient voltage to the actuator not allowing it to operate. I ran a wire directly from the battery to the wire look in the gate thinking this would solve the prob, it didn't. It was the ground clamp from the battery charger which when connected directly to the tailgate allowed it to work, so I started looking for a ground and discovered the prob. Then another issue developed. The latch would not work at all intermittently. Checked the voltage to the actuator from the dash switch and was not getting any voltage. At first I thought the button on the dash was defective but tested this with an ohm meter and it was completing the circuit. About a month ago I discovered that the switch would work when I pushed the trans all the way into park. There is a safety switch that prevents the window button on the dash from working if the vehicle is not in park. The linkage needs to be adjusted to allow the switch on the trans to close so voltage will go to the button on the dash. Those were the two issues with the rear window hatch release not working on this rig. Some probably already are aware of the safety switch, I wasn't, had to learn it the hard way. The bad ground was discovered through trial with alternate voltage sources. Hope this info will help someone along the way

M