Where can I find on line a wiring diagram for a 1989 Chevy S10 Blazer?

Question

Specifically for the heater/ac wiring.

Answer 1

Go here------->

http://www.eautorepair.net/

…and for a modest annual subscription fee, yo can have access to ALL the published information available for the little trucklett including the wiring diagrams, vacuum diagrams, repair information, illustrations, diagnostics, recalls and TSBs.

Happy Motoring

Answer 2

Repair manuals that are sold at parts stores have good wiring diagrams in them and they are under 20 bucks