Ok so i have a couple issues..
First my a/c.. when i am running the a/c on normal 1,2,3 levels it works fine. however when i want to blast it the ac just stops working. i think it might be a resistor and would like a 2nd opinion.

Second my power levels... My truck accelerates fine from the 0-30mph range.. but when i am on the highway and want to merge or pass or just go fast for no reason i have alot of draw from the engine but it just barely creeps along from about 30-50 mph range. Im thinkin it might be a clogged fuel filter or fuel pump.

please help

 

Lets start with some vehicle information.

If 1, 2, & 3 work, then the problem is likely with the high speed relay.

Are there any stored trouble codes?

 

thats a negative on any codes

 

oh and i have a rattle that sounds like metal on metal comin from the cat.. any suggestions

 

what year is your blazer

 

pluged cat. is rattle inside? or is it a heat shield? if inside, I would replace cat.

bernie

 

its a 96. Its the heat shield i just put some strapping on it seeing as how im gonna replace the exhaust here shortly. I just changed the fuel filter and it was GNARLY couldnt see the white paint in the parkin lot through the black funk that came out of it. It was def. a 150k mile fuel filter. The power levels picked up alot but it still hesitates like its gotta think about goin up in RPM's