2000 Chevy Silverado Z71 92k miles.
Tensioner pulley makes noise so it gets a new belt and pulley tomorrow, no big deal.

Larger problems.
AC does not work. Will not blow cold, what is the best way to diagnose the issue.

It has the beginnings of the typical Silverado rocker rust.
Drivers side is the worst. Should I just sand it down use some sort of rust encapsulator then LineX or some sort of spray on bed liner?

Drivers side corner is the worst. Almost all the way through.

This message has been edited. Last edited by: Black92LX,

The Silverado's AC blower motor resistor are bad to crap out on this year model. Check to see if the AC compressor is kicking on and off. It could just be the fan not working. The resistors are easy to source online and are ~$50. They are a bitch to get to down under the passenger side, but doable.

If the compressor is not cycling then you are low on refrigerant, which means you likely have/had a leak. You will need to vac it down and determine where the leak is.

Can't help with the rust as I am in the South and know nothing of it.

I would use something like POR15 on the rust

I had a '98 and just wire brushed all the paint and rust off, rolled on a THICK coat of bedliner. You can fix the corner with sheet metal and spray foam (did the whole rocker of my brother's Exploder this way) or the part is cheap, you just have to have someone cut out the old and weld in the new (and paint).

I had my truck two years after the bedliner trick and no more rust came through. You have to treat the inside of the doors and rockers with something too. I used spray bedliner in a can after I took the door panels off to get in there.

A/C could just need a charge, too- but the resistors were notorious.

quote:

Tensioner pulley makes noise so it gets a new belt and pulley tomorrow, no big deal.

So we're clear, which belt? On the V8 engine, the belt that runs the alternator, steering pump and fan/water pump does not run the A/C compressor. That has its own little belt. It is accessed by taking the lower front plastic splash pan off.

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It has the beginnings of the typical Silverado rocker rust.

That same rust will take out the steel brake lines. Look especially underneath approximately where the front of the door meets the rear of the fender. Another common failure is the line going to the rear rusting between the gas tank and frame.

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No A/C

Does it blow air out of the vents but not cold, or does it not blow at all?

No AC sounds like the compressor seals are bad and the refrigerant leaks out.
Charge it and see how long it lasts.

That drivers side is perforated through. That's fill it with fiberglass repair.

quote:

Originally posted by Bluecobra:
The Silverado's AC blower motor resistor are bad to crap out on this year model. Check to see if the AC compressor is kicking on and off. It could just be the fan not working. The resistors are easy to source online and are ~$50. They are a bitch to get to down under the passenger side, but doable.

If the compressor is not cycling then you are low on refrigerant, which means you likely have/had a leak. You will need to vac it down and determine where the leak is.

Can't help with the rust as I am in the South and know nothing of it.

Never had to fool with A/C stuff before. How do I determine if the compressor is actually cycling?

quote:

Originally posted by egregore:

quote:

Tensioner pulley makes noise so it gets a new belt and pulley tomorrow, no big deal.

So we're clear, which belt? On the V8 engine, the belt that runs the alternator, steering pump and fan/water pump does not run the A/C compressor. That has its own little belt. It is accessed by taking the lower front plastic splash pan off.

quote:

It has the beginnings of the typical Silverado rocker rust.

That same rust will take out the steel brake lines. Look especially underneath approximately where the front of the door meets the rear of the fender. Another common failure is the line going to the rear rusting between the gas tank and frame.

quote:

No A/C

Does it blow air out of the vents but not cold, or does it not blow at all?

Yes, I was referring to the serpentine belt and not the A/C belt and tensioner.
Pulled the belt and spun the pulley and it was noisy.

Brake lines and rear calipers have already been replaced due to the rust.

Air comes out of the vents it just does not get cold.

quote:

Originally posted by ScreamingCockatoo:
No AC sounds like the compressor seals are bad and the refrigerant leaks out.
Charge it and see how long it lasts.

That drivers side is perforated through. That's fill it with fiberglass repair.

I don't have gauges. Are any of those cans with gauges you see at the auto parts place worth a lick? Or will I need to buy a set of gauges?
I have been luck in my 20 years of vehicle ownership now never to have an A/C go out so I have never fooled with it.

I had to fix a blower motor resistor in my 2000 a few years back. I think the usual sign is it will work on say, high power, but not on other powers. Or it will blow but make a ton of racket. Easy fix and might as well do it just to make sure.

If air comes out but it won't get cold, sounds like compressor is either bad or leaking refrigerant.

My Z71 went 273k miles and then I sold it for $5300 back in 2014. We dont really run into rust down here so that helps. Replaced it with a 2009 Z71 amd expect the same experience.

On a >2005 model with electric fans the compressor is easy to see, but on older ones it is difficult. Take that splash pan off and you can see if the compressor is operating, or that there is even a belt on it, for that matter. This is often overlooked. I've lost count of the number of these trucks I've seen with a brand new main belt and the compressor belt in tatters or missing. When the AC is operating the front plate of the compressor clutch should be turning along with the belt. If it is not, most of the time the refrigerant is very low or empty and the pressure switch on the accumulator breaks contact.

Rocker rust is death to a truck. There were some years when foam insulation was injected into the area, and it collected water. The rust reportedly is from the inside out, and merely removing it and painting or covering the metal does not stop the process. I priced replacing my rockers and IIRC, the bill would have been $1500. The rockers have to be cut out, new ones welded in, primed, and then painted. I was going to do Line-X on those surfaces to minimize painting costs, but even that was pricey.

Not to sure about the AC. As far as the rockers go, it's best to replace the rockers completely. I'm in the process of getting all necessary replacement panels to replace my rockers. I went with universal rockers I found on Rock Auto. Seeing I have a 04 avalanche, the panels are a bit tricky to find. The rockers will need to be cut out and welded in, or they do make slip on models but that's just a band aid. I plan on once I get the new rockers and corners installed, I'll coat them in the roll on bed liner you can get almost everywhere.

It would appear that the compressor is not cycling on.
I turn the A/C on but the front of the compressor never spins. The backside that the belt is connected to salons just fine the belt is good and no squeaking. The front portion of the compressor never spins so I presume it is not functioning.

What is the best way to go about determining if the compressor or is bad or another issue?

The vents work and change between speeds it just blows hot all the time.

quote:

Originally posted by Black92LX:
It would appear that the compressor is not cycling on.
I turn the A/C on but the front of the compressor never spins. The backside that the belt is connected to salons just fine the belt is good and no squeaking. The front portion of the compressor never spins so I presume it is not functioning.

What is the best way to go about determining if the compressor or is bad or another issue?

The vents work and change between speeds it just blows hot all the time.

sounds like it could possibly be the clutch of the compressor is broken, but most often I believe it is quicker and more efficient to just replace the whole compressor.

The clutch probably isn't getting power. Test for battery voltage on the (IIRC) green wire and ground on the black wire. While it is disconnected, check the terminals for spreading apart or melting.

I believe it's common for a system to have a low refrigerant switch. If the refrigerant is too low, the system won't energize the electric clutch on the compressor.

I know lots of guys check this by power-probing (adding 12v to the compressor to engage the clutch) to check for clutch function.

Don't ever do that to a Honda though. Backfeeding power to the compressor damages the ecm.

I'm not very mechanical but will offer my 2 cents based on my recent experience. My AC Compressor wasn't coming on and when I filled the refrigerant back up it immediately kicked back on and it has been working great ever since. Hopefully your issue is just low refrigerant.

quote:

Originally posted by Black92LX:

quote:

Originally posted by ScreamingCockatoo:
No AC sounds like the compressor seals are bad and the refrigerant leaks out.
Charge it and see how long it lasts.

That drivers side is perforated through. That's fill it with fiberglass repair.

I don't have gauges. Are any of those cans with gauges you see at the auto parts place worth a lick? Or will I need to buy a set of gauges?
I have been luck in my 20 years of vehicle ownership now never to have an A/C go out so I have never fooled with it.

You really don't need gauges.
I'd put a can in it with the cheap hose, then add more ass it needs to cool more.

I bought a can of refrigerant and a hose with the gauge that you dial in the outside temperature to determine proper pressure.
Everything I am reading says it needs to be recharged with the compressor running.