Heat/AC Problems - Engine Failure Imminent?

[HazMatt]

Hi.

As you all know, the SHOs get those super sweet heater clusters. We can spin a little wheel, set our desired temperature, and what not.

My problem is my heater. When I run 90° with the fan on Hi and the route being Vent, I get little to no air at all? Heres where it gets weird...

When I click the "OFF" button on the cluster, my heat turns on FULL BLAST, but its not coming from my vents. Maybe Defrost, or Floor, but its definitely blowing, and HARD.

I got some noises coming off my pulley system that isnt natural, doesnt take a rocket scientist to figure that out. Is this entire failure due to 1 pulley ? If so, where is this specific pulley located so I can swap it? Thanks in advance.


P.S. Also is there anything I NEED to know about removing the pulley belt and putting it back on? Any special tools etc?

 

[hawkeye18]

do you have an ATX or MTX? ATXs have an automatic tensioner that you just need to tighten (which really loosens the whole assembly) the center bolt with a 17mm wrench... The pulley noise is either your idler pulley or your A/C Clutch... your engine is more than likely fine, unless the belt comes off and you drive for a while with no water pump.

Is your battery light on? The EATC (what you call the heater cluster, it does A/C too lol) is VERY sensitive to fluctuating or low voltage, and will flake out at the first sign of both. It's kind of the canary of the charging system. Also, make sure you don't have vacuum lines reversed somewhere. Also, there may be a short in the wiring...

 

[HazMatt]

ATX. My belt blew yesterday. Im going to put a new one on and check my pulleys. Once this is fixed, where should I start with my heater problem? its 16 degrees out.

 

[hawkeye18]

well, while the belt is off, spin all the pulleys. Both the idler pulleys (between the water pump and alt, and right below it to the left of the AC pulley) should spin freely and make no noise. The Alt pulley should have some mass behind it (it is spinning 7 pounds of metal) but otherwise be free. AC pulley should spin freely as while the car is off it's not mated to the clutch. If it doesn't spin free or doesnt spin at all, your AC has some problems and you should change your clutch (this is quite doable in-car and doesn't require removal of the whole compressor; I've done this myself). Crank shouldn't spin for shit, I think that's pretty obvious. The others should spin pretty easily.

Are you handy with a multimeter? You need to start getting some voltage measurements. What year is your ATX? I will post wiring diagrams of the HVAC system for you.

 

[hawkeye18]

 

[kornsho]

As far as the heater fan coming on when you hit OFF - Sounds like the Blower Moter Control Module behind the glove box. The fan belt might be seperate.

Korn