My gmc 2004 safari blower is not working

front blower has a problem rear does not

there is a blower relay circuit board located right by the blower motor which sounds like your problem to me i've worked on several that had the same type problem and thats what it was. the two blower motor wires will plug into it and there are two screws that hold it on

to me it sounds like a loose wire may be exposed to metal touching that one point or another and it's definitely an intermittent problem and that's what it sounds like to me

It could be your fuse or relay or blower motor resistor

there is a bad connection on fan speed switch remove and check for a melted connector.

blower motor is worn. hit it while its on and it will start working again but will need to be replaced eventually

does it work on heat mode if not then it is probably the blower motor switch in the dash or the blower itself

ac on a 2005 gmc yukon not blowing and cant here compressor the rear ac of the truck is working fine, are there any fuses i can check?

Got the same problem, front blower does not work but the rear blower runs great...Need Help!!

two different problems !

Rear heater problem: find under the hood where is hose for cooling liquid goes to front heating core!
you will see there also vacuum tubesgoing in to little valve ! disconnect the vaccum tubes ( engine off)
and spray in wd 40 in to the vlave ... valve is stuck and wont open flow to rear heater !

you do not have to replace tha thing . its very well made and because you dont turn this often in summer
it gets stuck. i had same problem. also make sure vacuum is working - Engine running turn rear heater on - vacuum sucks to open valve. and before that make sure fuse is ok .

for rear AC mine does not work either and it is leak on pipes that go from front to rear .. 10 feet of pipes and tubing $$ expensive repair ... forget it ... open the window...

jebadiah