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My A/C unit kicks on but it doesn't get cold. It made a strange noise in the beginning, this is also while it would get cold on the interstate but not while it was idling. Any suggestions?
 

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I would suggest having the system recharged if it hasn't been recharged in the past 3 years.

Do not engage the compressor at all as you might damage it. Turning on the front windshield defrostor will engage the compressor on my '99 Passport, but I'm not sure if it will do so on yours.

Most of my cars have needed recharges every 3-4 years.
 

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i had the same symptons on my 01 rodeo it was the compressor. mine made like a sizziling/gringing noise when engaged. mine would also get cold anly if the RPM's were high like when driving.
 

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Engaging (or trying to engage) the a/c, either via the a/c switch or the defrost switch, when the refrigerant pressure is too low will not cause damage to the compressor, because there is a pressure switch that prevents the compressor from engaging if the pressure is below a certain point. If you've ever refilled a completely empty system, you can see this in action: with the motor running, you turn the a/c to full, then start refilling; after you add two or three cans of refrigerant, the compressor will suddenly kick on.
 

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There's a number of topics mentioning recharging the air conditioning,
but all a little "vague"... which about describes my own knowledge on the topic.

My 96 Rodeo started blowing progressively less and less cold a while back, and I put off doing anything about until the Florida summer really got up to full power... now I'm driving a 4WD sauna, and it's "fix-it-or-melt" time

I'm pretty sure that it uses R134, at least the little sticky label on the bulkhead implies such... and my local car-bits shop sells a kit, including bottle'o'cold and a pressure gauge, but I'm unlear on the correct procedure to refill the system, and how I know when enough is too much... I'd guess by the pressure reading? But what's the correct pressure?

Any clues would be very much appreciated...

Best regards
IanP
(expat Brit, wilting in the heat...)
 

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I recharged my 96 a few times before I gave up. I think it has a leak. But here is how to do it.

Start the truck and let it run. Turn on the AC full blast. Open the hood and you well see a pipe coming up out of the engine near the brake fluid resevior that has a green cap on the fitting. Take the cap off hook up the charging kit and open up the valve. The can might get really cold once you tap it.

The AC should start getting cold right away.
 

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OK, so following up on your own posts is just sad , but...

I figured out the details of the a/c recharge on my 96 Rodeo, so I thought I'd post here, for the benefit of any other confused souls who wander down the same road...

Firstly... verify what kind of refrigerant your vehicle uses. Mine was R134, the affordable kind, and needs a full charge of 1.43 pounds, acording to the little label on the bulkhead. This information is only really useful in telling you how big a can to buy.

I used a refill kit from "Interdynamics", off the shelf for about USD20 from my local Walmart. It includes a pressure guage and coupler hose, which you can detach and use again another time, with a (cheaper!) refill can. It also includes pre-mixed oil and a sealant, just in case.

Now, the important thing is to locate the right fitting to attach it to. There are high- and low-pressure ports on the system, and the refilling is done through the low pressure port. Attaching a flimsy little aluminium can to the high-pressure side is going to get you an Earth-Shattering Kaboom, and a brief shower of aluminium shrapnel around your neighbourhood. Not to mention fingers...

Locating the right port is pretty easy, at least on this model... The LP port is located on a vertical pipe up against the firewall, on the (US) driver side.

First slide, please:



Unscrew the little plastic cap from the fitting, noting that the caps are actually marked "H" and "L", but are otherwise identical, so that there is nothing to say that some prankster didn't change them over, in the past. The coupling hose from the refill kit is a snap-fitting, in this case with a sliding collar to lock and release.

The guage may, at this point, give a reading, but ignore it until the engine is running. So, once the can is coupled up, start the engine and turn on the AC, in "very very cold" mode. Note that the compressor may not run at this point, but don't be discouraged - there is a low-pressure cut-out, whch stops the compressor running "dry", if there is no refrigerant in the system.

Now, with the engine and AC running, check the guage. In this case, it was "gauges for dummies", since it was calibrated in colour-coded bands, as well as actual pressure figures....

Green (0-25 psi) for "Fill 'er up"
Blue (25-45) for "enough"
Yellow (45-65) for "probably too much" and
Red (65 -200!!!) for "much too much too much - drive carefully to a mechanic, avoiding bumps in the road!"

If, as in my case, the needle sits sulkily down in the green, about 5 or 10 pounds, then you can shake up the can to mix the oil, then go ahead and crank the valve, press the button, or whatever, to let the refrigerant flow. Stop to give the can another good shake, and check the pressure every 30 seconds or so... and note that it's like tyres, you can only get a valid reading when you stop the flow. At some point in the process, you'll hear the compressor start up, as you reach the minimum pressure. This is a Good Thing. If it doesn't... well, OK, now you can be discouraged.

Basic physics tells us that, with the coolant expanding and rushing out of the can, it's going to get cold. Indeed, the small print on this can warned about frostbite! As well as freezing your fingerprints off, the drop in temperature will slow down the rate of evaporation of the coolant, and thus the rate of refill .... so it pays to stop now and then, let it warm up a little, give it a vigorous shake.. I've even seen it suggested that you wrap it in a towel soaked in hot water, but I live in Florida, where the afternoon air is hotter than a sauna anyway - why do you think I'm so anxious to get my AC working again??? The complete process, with stops for warming (and cool drinks for me), took about 20 minutes, so be patient.

Another point to watch, is that the pressures quoted are for a particular air temperature - in this case, 75F. If things are hotter - i.e you just drove the car, or it's a hot day, the figures will all read high. I stopped the fill when it got to "blue", and left it overnight, slipping out in the cool early morning to check and top up - sure enough, it took another few minutes to get it back up to the "full" mark again.

Now, disconnect the hose - look out for the spray of coolant and oil as you unhook it, it's messy - replace the cap, clean up and enjoy!!!

I'm no expert, I'm just presenting a summary of what I learned about my particular vehicle... but I hope it may help somebody
Now, I'm off to go and sit in the car in the drive, where it's cooler than in my house !! :D

 

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IanP said:
I figured out the details of the a/c recharge on my 96 Rodeo, so I thought I'd post here, for the benefit of any other confused souls who wander down the same road.......

....I'm no expert, I'm just presenting a summary of what I learned about my particular vehicle... but I hope it may help somebody
yes, it sure helps me.

thank you for such a good write-up with such great pictures with such dumbie-proof captions :!:

i only wish to persuade you to follow-up one more time -- perhaps at the end of your fla summer? -- and give us the lowdown on how everything held up.

thanks again :!:
 
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