Larry, I checked with a light and mirror. The blower motor black/ground wire leaves the motor and is routed straight up and I can not see or get my hand far enough into the area to see where it goes. My guess is that it goes to a case to firewall screw right at the blower like I see Pontiac and Tempest sketches show.
I know there are either errors/changes/differences that have been made in wires in the area in '68 because Pontiac documentation does not even agree on the color of the positive lead to the blower. Compare the wiring diagrams from the '68 POntiac Diagnostic Manual compared to the '68 Wiring Diagram.
You know, I think I'm just going to run a wire from the blower to a case stud like the 69. It can't be seen anyway.
On the wiring discrepancies, I noticed that the lower diagram, like the one I have, isn't even the correct schematic for the Firebird. The "Master Relay" isn't used as a master but is for the high blower speed, like my 68 and most other cars.
Thanks for you and Pete taking the time to research this for me. One more problem down and XX to go!
