Guys, I have 2 trucks. a 1986 chev 1/2 ton and a 1993 gm 2500 with the 6.5l diesel. When cold the 86 fan wont move when the truck is not running and the 93 6.5 the fan is easy to spin. Which is correct. the 86 seems to have loud fan noise when running at 2000rpm and the 6.5l has heating issues...

Wassup I got a 2004 gmc sierra 1500 5.3 when I'm using the ac all speeds work fine heater and ac works fine but when I turn it down to 0 and go on freeway air starts to blow thru the vents not ac or hot just air like I left it on speeds 1-3 completely turns off fine when truck is turned off also...