fan clutch probs.

i have a 04 trailblazer with 61,000 miles which the dealer said i needed a new fan clutch cause the a/c was blowing hot when stopped at traffic lights. new one was put on now the truck gets horrible gas mileage and roars like a 18 wheeler. i kinda like the new sound, but after reading alot of other posts i think something is still wrong. i took it back they said they checked the program and everything is fine. what do u guys think?:banghead:

If it is not overheating and the A/C works maybe the clutch is also working right.

If you can hear it or feel it is working.

Check gas mileage with air off and then with air on.
Let us know what the actual gas mileage is both ways.
MT

If the fan is roaring constantly, either it is bad, the engine is running hot and the pcm has the fan in the high position, or they did not re program the pcm.

If you don't like the way the fan works. Noise, RPM robbing, check PCMforless. They are coming out with an e-fan mod for the TB. The claims are better cooling & somewhere around 15 HP gain! I think that they are providing the electrical harness & instructions for you to install your own Corvette or Camaro fan shroud & fans. Apparently it's easier than it sounds. BTW I just had my fan clutch replaced & the A/C does work better at idle & I have only heard it roar once.

Is the clutch fan the same as the actuator?
I just had the actuator replaced 2 wks ago due to a clicking sound coming from the fan. Sounded like the fan was stuck and couldn't figure out which setting I had it on....(blow air toward the windshield...or in my face).
Anyway, the actuator helped my fan-clicking sound.
I'm still having a problem with my A/C not blowing cold air at an idle. It still takes me driving a few miles before it decides to blow cold air. Seems like you fixed your problem w/it. Any other suggestions? ('02 TB LS, 104,000 mi's.)

No....the actuator has to do with your BLOWER fan, for the heating and A/C system on your TB. The FAN CLUTCH is mounted on your engine, right behind your radiator, and is part of your engine cooling system. If it is roaring constantly, you definitely have a problem. I replaced mine at the beginning of the summer. If you aren't very mechanical, definitely have a solid mechanic do the work. Your hands will thank you.

Thanks for the help gmpartsman. Another question (actually 2-part quest.)....do you think if I get the fan clutch replace that it would help with the current A/C problem...where it only blows cold air after I drive it a few miles and not while idling....as well as fixing the problem of it cycling by blowing cold/hot/cold/hot before it blows cold?? Thanks for the help...I'm just at my wits end.

The AC pressure switches were also problematic with the same symptoms at times.

Agreed. GM OEM'd a great number of defective A/C high-low switches and a great number of defective fan clutches in Trailvoy model years '02 into '05. They're separate issues. If you wanna use this board's "search forums" function and type in fan clutch, look at the threads and the info I posted 6/14/07 (post # 11 under one of the fan clutch threads) for the part # of GM's new/replacement fan clutch and the TSB # that has the PCM re-flash instructions. The re-flash is required to get the system to work right. I'll agree it's true that some owners had complained of poor A/C performance that turned out to result from a defective fan clutch. So your A/C's high-low switch (mounted to the shrader valve on the accumulator) itself may be OK. If not, it's a cheap and easy fix. The point is that GM addressed both defects with parts updates.

Thanks for the help gmpartsman. Another question (actually 2-part quest.)....do you think if I get the fan clutch replace that it would help with the current A/C problem...where it only blows cold air after I drive it a few miles and not while idling....as well as fixing the problem of it cycling by blowing cold/hot/cold/hot before it blows cold?? Thanks for the help...I'm just at my wits end.

It sounds like you're chasing 2 different problems here. i completely agree with what everyone else has said here about the fan clutches- they suck. My envoy (envoy, trailblazer- same difference) had issues with blowing warmer air on hot days at the beginning of this summer. I replaced the fan clutch and performed the software update and immediately noticed that the fan stays on longer on cold startup- which means it's doing its job by pulling more air through the radiator/condenser on hot days when you need cold air.

A real quick diag on your fan clutch would be this: start it up and have some one take a hose and spray water through your front grille onto the condenser (with your engine running and a/c on). If your a/c air gets cooler, then the most likely cause is the fan clutch. That's how i diagnosed mine. That means the fan clutch isn't engaging enough to pull the needed air through the a/c condenser.

The second problem you mentioned with the air going hot/cold/hot/cold could very possibly be a temperature door actuator issue. GM has a good number of problems with these actuators.