im at work wasting time since we dont have any work to do today . . . (yup getting paid to sit on my *** )

 

Same here! ^5 BTW, it seems alot of a/c problems crop up during the beginning of summer. Maybe you can write up an editorial on maitaining the a/c system during the off months?...

 

that actually a good idea, ill have to talk to pete about that and putting together a basic A/C maintance/repair thread . . .

 

Yeah, I meant you and pete. I'll hang out and thorw in a comment or two from the peanut gallery. LOL!

 

Thanks, guys, for the great feedback. I need to add a couple more issues for you to tackle:

1. When the D starts to overheat (only when sitting still - never while moving) - we've had the AC on the entire time and the AC works great - there's a 'grinding'-type noise coming from the front of the engine. It gets really loud. Like I said, it only happens after the truck starts to REALLY overheat and with the AC on. We were just told that the noise was coming from the air compressor clutch (that the bearings were bad) and that we need to replace the entire compressor. Our question . . . if the clutch was BAD, would that noise occur WHENEVER we engaged the AC and not just after it has run for 10-20 minutes and started to overheat? Can bearings go bad and then work fine and then go bad again?

2. We were also told that it was DEFINITELY NOT THE FAN CLUTCH. However, the fan NEVER kicks in and the truck never 'roars' like it used to (when the fan was engaging). They want to just replace the thermostat to SOLVE the overheating problem, without touching the fan/fan clutch?? Everything you've said, and also what I've read other places, says to 'turn the fan'. Which fan? The large one (that works) or the little one, in front (that's NOT turning)? With the truck OFF of course.

3. We're new to this so we need some clarification . . . the round, silver part behind the main (large) fan is the fan clutch, correct? Having said that, does that silver thing actually work as a clutch for the smaller fan in front of the large fan? This has been a REAL topic of discussion!

4. We did replace the fuse and relay and it had no effect on the fan motor engaging.

I'm just trying to figure this out 'logically':

The odds of the air compressor clutch going bad and the air compressor continuing to work, without issue or noise, for the better part of 30 minutes before FINALLY making the grinding noise (and that noise isn't there when you RESTART the D later with the AC going), just don't add up??

Our D has over 172K (this is the FIRST major issue - we LOVE this truck!), and is well past due for a thermostat, so replacing it isn't a problem. However, from what I've read, if the thermostat is actually BAD, wouldn't the truck run hot on the highway as well as sitting still? And, will replacing the thermostat allow the fan to kick in?

Please help - money is tight - we need the truck - this whole issue is sending us to divorce court!

Thanks

 

ok, im going to break this down for you as best i can right now

an A/C clutch wouldnt cause a grinding noise unless it was only partially engaging, the bearings in the a/c compressor pulley COULD be bad, but then they would grind consistently, check the pulley by taking off the serpentine belt (yea i know, but bear with me) and spinning the compressor pulley by hand, if it wiggles, or wobbles, or doesnt spin straight, true and smooth, you have a bearing going bad, unfortunately afaik that means you need to replace the compressor



the big fan in front of the engine is driver by a clutch, try spinning it by hand, if it is good it will only spin a little, if it spins more than 1/2 a turn i would replace it for sure, chances are this your problem since this is the fan which is known to cause the 'roar' sound you describe (especially in cold weather)

this is a picture of the clutch itself,


can be purchase here http://www.napaonline.com/Search/Det...+50022+2022007

this clutch ONLY DRIVES THE LARGER FAN!!!!!!!!!!!!!! (anyone who tells you otherwise is an idiot)
if the smaller fan is the one not working it is either a bad relay, loose plug, or a bad motor (the smaller fan is electric, and SHOULD go on with the A/C or when the engine gets over 215*F


then try a hot feed from the positive batter terminal to the green wire from the smaller fan (crawl underneath and unplug it to see which one im talking about) if the fan doesnt turn on then you need a new e-fan

no air compressor on these trucks, only a/c (refrigerant) compressor, but i explained how to check that above, chances are it is something else (bad fan clutch IMO, or a bad e-fan motor making the noise)

the thermostat would cause a higher running temp, or overheating, or underheating if it were bad, depending on if it is a failsafe version or not, never hurts to have a new one handy.


ok, i hope i got everything, if i missed something ask again as i am gone on this for right now

 

I would think it is plausible that the "Grinding" he is hear is being caused by a faulty fan clutch... I had an older chevy that did the same thing, everytime the fan clutch decided it was time to make the fan do its thing it would grind bad... of coarse when i poped the hood and spun it it turned like a helicoptor at take off.

 

yup definitely a good possibility of that being true

 

Well I think he needs to replace with fan clutch. Next make sure the small electric fan is coming on when the A/C is on, if not fix the connections or replace the electric fan.

 

i acciddently cross threaded my fan clutch nut is there any way i could have it rethreaded