AC Issue

[2002TLCyes]

Here's the situation: I have a 2002 land cruiser with the built in navigation screen. When I turn the AC button on, I don't hear a compressor kick in like I'm used to hearing in every other vehicle I've driven. And with 70 degree temps, today was the first day I could test it as far as its cooling capabilities, which are nonexistant. I tried turning the rear AC on too, and it doesn't make any difference either. No condensation dripping under the truck either.

Any ideas? The heat works. Fan blows fine. Just no cold.

Thanks

 

[TXSunDevil]

Have you checked to see if there is any freon in the system? A low pressure switch will keep the compressor off.

 

[2002TLCyes]

To be honest I don't know anything about AC systems. Where would I check for presence of freon? If it is low, doesn't it mean there's a leak somewhere, otherwise it would still be there?

Thanks

 

[TXSunDevil]

Yes if it is low on freon there is a leak. You would need a set of gauges to put on the system. There should be a tap under the hood on a silver ac line.

 

[flintknapper]

To be honest I don't know anything about AC systems. Where would I check for presence of freon? If it is low, doesn't it mean there's a leak somewhere, otherwise it would still be there?

Thanks

Yes, it would mean there is a leak (or leaks) somewhere. Refrigerants are not a 'consumable' (they are not used up in operation...as is engine oil).

BUT....there are more than a few reasons why your system might not be working (low refrigerant just one of them).

Since you are not familiar with your A/C and we don't know your mechanical abilities, I would recommend you take your vehicle to a respected mechanic for diagnosis.

They can very quickly determine IF the compressor clutch is engaging or not. If not...they will hook up a set of gauges to read the 'static pressure' which according to ambient temperature will tell them if there is any liquid refrigerant in the system at all (but not how much). Also... if the static pressure is sufficient to activate the trinary switch.

IF they determine low refrigerant level is the reason the compressor isn't kicking in...they will contact you and offer you options.

 

[nissanh]

Isn't the AC stays off when the outside temperature is low?

 

[2002TLCyes]

Ah ok I see. So no sense in me throwing money at it in the way of buying those freon refill kits then..

I wouldn't say I'm completely mechanically dull, I just never took the time to learn about AC's or messed with them. Is there a way for me to determine if the clutch is engaging myself? If it isn't, is that something I can fix myself? Sounds like this is one issue most people recommend taking to the AC shop.

 

[2002TLCyes]

Isn't the AC stays off when the outside temperature is low?

Is that true? My radio read 70 degrees outside today. I figured surely that should be warm enough to let it kick in.

 

[flintknapper]

Ah ok I see. So no sense in me throwing money at it in the way of buying those freon refill kits then..

I wouldn't say I'm completely mechanically dull, I just never took the time to learn about AC's or messed with them. Is there a way for me to determine if the clutch is engaging myself? If it isn't, is that something I can fix myself? Sounds like this is one issue most people recommend taking to the AC shop.

Yes, you can start the engine (A/C off) and visually watch the compressor as someone switches the A/C on. The compressor 'clutch' is a simple electro-magnet. The 'click' sound you normally hear is the clutch engaging (though I can not hear mine from inside the vehicle). But you can also SEE it engage.

Just pull up any Youtube video on compressor clutches (they all work the same) and you will see what to watch for.

IF it is not engaging (and most likely it isn't) then we need to determine why. The most 'common' cause is a low refrigerant charge. There is a pressure switch in the system which will not allow the clutch to engage when pressure is too low (in order to protect the compressor).

So IF yours is not engaging and IF the reason is a low refrigerant level then you could buy one of the refill kits, hook it up to the low side (the only side it will fit on) and try to charge it enough to get it to operate.

Most of the recharge kits have a cheap pressure gauge on the can/hose. It will give you a rough (and I do mean rough) idea of your low-side pressure. But for the purposes of only assessing whether or not your clutch and compressor will work (eliminating any electrical issues), it might be worth a try.

I usually advise against this method....if I know the person is inexperienced dealing with A/C units, because its quite possible to hurt yourself and without a proper set of gauges (and knowing how to use them) very little useful information is gained.

Now...having said that, if you just happen to be one of the lucky ones. Your system might only have a slow leak. Everything else might be in good shape and adding refrigerant (if the system is too low) WILL satisfy the minimum pressure requirement and the unit should start to work again. But even then...it will need to be properly charged, the leak found and monitored to see if it warrants repair.

 

[2002TLCyes]

Thank you very much for the detailed writeup

 

[white_lx]

If this is a NY vehicle, then there is a pretty good chance that there is a leak in the lines going to the rear A/C. The road salt pits the aluminum lines. Mine lasted only 8 years, despite undercoating. You can cap them if you don't want to spend too much money fixing it. That's what I did and 7 years later the A/C is still working. See here Rear AC Line caps

 

[2002TLCyes]

It has been a NY vehicle... What's in those lines going to the rear AC? Is it freon? Is it that difficult to find caps that I have to order them special made in small batches like artisinal cheese?

 

[white_lx]

It has been a NY vehicle... What's in those lines going to the rear AC? Is it freon? Is it that difficult to find caps that I have to order them special made in small batches like artisinal cheese?

Yes, R134A refrigerant. Look just behind the passenger wheel well. You will see two aluminum lines. One is 5/16", one is 3/4" (IIRC). They may be covered in black foam. See if you find any pitting in that area.

I used these caps from McMaster Carr McMaster-Carr . You may be able to find caps for refrigerant systems as well with o-rings, but these have been fine.

You will need a 3/4" and a 5/16" (IIRC). The pictures in this post show you where: Rear AC cap question - URGENT
There is also reference in this same thread that the actual line replacement is not too bad, so you may want to check into that as well.

After cutting the lines, you need to evacuate the system and then re-fill. Not a very difficult thing to do, but you need some special equipment. This might give you an idea of what is involved:

 

[flintknapper]

If this is a NY vehicle, then there is a pretty good chance that there is a leak in the lines going to the rear A/C. The road salt pits the aluminum lines. Mine lasted only 8 years, despite undercoating. You can cap them if you don't want to spend too much money fixing it. That's what I did and 7 years later the A/C is still working. See here Rear AC Line caps

^^^^^^^ Excellent suggestion. I agree that is a spot with a high likelihood for failure.

Man, I feel sorry all the folks that live in the 'rust belts'. I've seen unbelievable (for me) pictures of the underside of vehicles that have been exposed to the elements and salted roadways.

 

[Spike555]

The rear a/c lines on these are prone to corrosion and pin hole leaks, the lines run from the passenger side of the engine, down the wheel well, under the rocker panel, right were all of the dirt and road salt and everything else your tire kicks up is sure to hit it.
My truck is a '04 and the original owner had the rear a/c lines replaced, and then I spliced them this spring. They only do not last very long.
I spliced mine, using a tube cutter I cut out the bad section and spliced the two lines back together. Then refilled the system, works perfect.

https://www.amazon.com/gp/product/B0083H5ES0/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

 

[2002TLCyes]

If I'm going the capping route, what exactly does that entail? I suppose I need to decide what's a good place to cut the lines going to the rear. After I do that, how do the caps fit on, do I need to cut threads onto the cut ends of the tubes to accept the McMaster Carr caps for example?

 

[2001LC]

Living in your region assuming you've rust on the undercarriage, leak is very likely.

But I did not see if you visually inspect to see if compressor clutch is engaging. Do this with AC turned all the way to cold and fan on. If it engages at full cold and blows cold air, it could be sensor hose in the cabin fell off. If this the case, you're lucky, it's a supper easy fix.
Read through Snowy in my signature for this fix.

Oh, and your High side of AC line runs along tops backside of radiator above fan shroud. Can't miss it "H" on gray cap!
Low side "L" near fire wall PS.

If IIRC on 2002 the window to visually inspect AC fluid/gases is between radiator support and grille, DS, down near frame.

 

[spaber05]

I'm having this same issue now! (Boston here, but VERY minimal rust underneath due to an OCD owner )

Previously, the AC Light would flash then clutch would disengage. Dealer recharged, found no leaks, and wanted $400 to investigate a relay underneath the fuse block in the engine bay. I hadn't had time to research everything myself so I declined that, bought a new relay (P/N 90987-02028) per 'Mud and other Lexus/Toyota site threads, and bingo, problem was solved.

Then, yesterday, same symptoms as OP. Fan blows, AC light stays on but no clutch engagement!

For New England, my truck is about as rust free as you can get so I'm doubting corroded lines but not ruling it out.

 

[2002TLCyes]

Living in your region assuming you've rust on the undercarriage, leak is very likely.

But I did not see if you visually inspect to see if compressor clutch is engaging. Do this with AC turned all the way to cold and fan on. If it engages at full cold and blows cold air, it could be sensor hose in the cabin fell off. If this the case, you're lucky, it's a supper easy fix.
Read through Snowy in my signature for this fix.

Oh, and your High side of AC line runs along tops backside of radiator above fan shroud. Can't miss it "H" on gray cap!
Low side "L" near fire wall PS.

If IIRC on 2002 the window to visually inspect AC fluid/gases is between radiator support and grille, DS, down near frame.

Thanks for the details. I know the AC light stays on, but it doesn't blow cold air. Just whatever temperature outside air is. Nor do I hear anything engage, however I haven't looked under the hood when someone else turns the AC on. Where should I be looking?

 

[2001LC]

Ok I assume you did test with temp in full "COLD", as you did not say. You must turn to full "cold".

In the video above, he zoom in on compressor and mentioned it. The pulley the belt turns on the compressor will always turn with engine running. But the parts just in front/attached of/on pulley, is stationary when not engaged.