a/c ccompressor?

[michael1]

99 ranger 4wd 4.0

a/c has started to lose its cool recently and went thru the threads and it seems that it it may be the compressor or the pressure cycling switch.

symptoms are compressor clutch (?) cycling on and off every 3-5 seconds. air is cool but not where it should be.

if its the switch, where is it and what to do to troubleshoot.

I know it should be taken to a real shop but am strapped for available time right now. would buying a re-fill can with the gauge at least let me know if the system is low and then adding if needed work as a temp replacement?

Thanks

 

[Wicked_Sludge]

system pressure is probably too low. those little do-it-yourself a/c kits are crap. my advise is leave it be until you can have a shop properly recharge the system for you.

 

[4x4junkie]

Agreed, those cans can be dangerous to your system (the vast majority of them include additives that will just gum up and clog your system). Those stupid little gauges that read the low-side pressure only are also 100% useless without knowing what the high-side pressures are.

Your symptoms sound characteristic of low freon (very gradual loss of freon over time is normal). While there are ways to replenish the system sufficiently at home without using a set of gauges, if you haven't messed with A/C before (and know what cans to buy, and what to avoid), I would agree with having a shop check it. Shouldn't be more than $100-150 to have it replenished with freon (R134a). They will also do a leak check for any abnormal leaks.


BTW, don't continue running the A/C like that, a low-freon condition will likely starve the compressor of lubrication, causing it to fail (which will then lead to EXTREMELY COSTLY repairs--- the whole system will then be contaminated with compressor debris).

 

[MAKG]

Naw, he can keep running it. The low pressure switch is working; that will protect the compressor.

Now, it's conceivable that the problem is the reverse of that -- a disintegrating compressor plugs the orifice with debris and leaks -- but it's more likely to just be a run of the mill old O-ring. In which case, the O ring needs to be replaced (i.e., recover refrigerant, replace O-ring, evacuate, charge).

But I concur that a shop is necessary here. DIY A/C is only feasible if you can afford to fix the inevitable mistakes. They usually cost more than the original problem, and you WILL screw up without an electrical vacuum pump and a decent pair of gauges.

 

[4x4junkie]

Freon carries the lubricating oil throughout the system. If the freon is low, the oil won't be circulated as well.

 

[MAKG]

That's true, but if it's low enough to be dangerous, it won't run. It's why jumpering the low pressure switch for more than an instant is risky.

Oil is lost in proportion to the refrigerant. It's not all gone at once.

 

[michael1]

Thanks for the responses. Looks like I will have to make some time to get to the shop. Can someone actually verify whether running it for now is doing harm. Seems to be alot of conflicting opinions in the various threads I read thru. Thanks again, Michael

 

[Wicked_Sludge]

ive personally seen a/c compressors seize due to low freon levels before the low pressure switch shut down the system. theoretically, this shouldnt happen, but it does.

if you'd rather play it safe, just unplug the electrical connection at the a/c compressor. this will keep it from kicking on until you can have the system checked out.

 

[Accord4tehloss!]

Its also really hard on the a/c clutch cycling it every few seconds.

 

[4x4junkie]

if you'd rather play it safe, just unplug the electrical connection at the a/c compressor. this will keep it from kicking on until you can have the system checked out.

Good advice, the A/C on a '99 is set to run in nearly every vent mode (not just Defrost). Unplugging the clutch coil will keep it shut down in the meantime.

 

[michael1]

Okay, finally got to the shop and the result seems to be:

Evaporator, expansion valve, accumulator, and service valve, as well as the freon.

Cost for all these parts was $370.00 ($120.00 for freon which seems to me to be abit pricey).

Labor is to be $420.00 (7hrs @ 60.00hr)

I was told that the dash has to be removed in order to replace some or all of these parts as well as flushing the system.

I haven't started to shop around for parts yet but wanted to hear from the jury about the diagnosis and work involved as well as the price. Also any place on-line to go for the parts.

Thanks, Michael

 

[Wicked_Sludge]

i have a hard time believing that the accumulator AND evaporator need to be replaced. the orifice tube (or expansion valve) is probably just a precaution.

 

[MAKG]

The orifice tube costs like $1.50. Replace it.

The evaporator MIGHT be the source of a leak. The accumulator needs to be replaced due to the dessicant. The low-side service valve is part of the accumulator. If the high side valve CORE is being replaced, that's another $1 part.

$120 for two cans of R-12 is reasonable. For R-134a, that had better come with a BJ. Look for a mistake. R-134a is NOT Freon.

 

[4x4junkie]

I tend to agree, it sounds like you're getting screwed. Unless they somehow were able to leak-test that evaporator, I highly doubt it needs replacing.
Also you do not have both an expansion valve and accumulator, one or the other (unless they were mistakenly calling the receiver an acccumulator, or the orfice, the expansion valve)

I don't see the system needing to be flushed either unless there was a compressor malfunction.

R-134a is NOT Freon.

"Freon" isn't the generic brand word for any refrigerant? (like calling facial tissues of any brand "Kleenex", or clear transparent adhesive tape "Scotch tape")?

 

[shadetree]

I would put in a can of refrigerant and use a "sniffer." If there is a leak, it will detect it especially if the sniffer is a name brand. You can't see dyes, etc., in evaporators, and condensers if it is small and in the obstructed areas.shady