Air Conditioning problem

[Milkman00]

Hello all

I have a 2000 Nissan Altima SE. As of recently the air conditioner doesn't seem to come right on EVERY TIME. When you turn on the air conditioner, the compressor engages, which drops the idle slightly, puts a strain on the engine, and the radiator fans kick on. You can definetly tell when it kicks on.

Sometimes, I start the car up, and the compressor doesn't seem to be engaging, even though I have the air conditioner switch on. At first I thought the A/C relay could be going bad. I switched it out, and it is still doing it. The weird thing is, although it doesn't immediately blow cold air, I will drive down the road for 5 - 10 or even 15 minutes, then it will all of a sudden kick on, and work with no problems at all for the rest of that trip...

My first thought isn't a freeon problem, because I would think the compressor would still kick on with low freeon, but it just wouldn't be as cold. Any thoughts??? This is driving me nuts (FLORIDA RESIDENT!), as I am getting ready to drive my car on vacation.

Any help is appreciated!

[pro_am]

If your talking about the blower motor fan not kicking on. I think that there may be a blower motor resistor which is a common thing to go wrong, (provided your system utilizes such a thing). You may want to check your manual and find out where that is and replace it. If it isn't bad and you replace it, hey it's cheap and think of it as preventetive maintenance.
Jake

[Milkman00]

Originally Posted by pro_am

If your talking about the blower motor fan not kicking on. I think that there may be a blower motor resistor which is a common thing to go wrong, (provided your system utilizes such a thing). You may want to check your manual and find out where that is and replace it. If it isn't bad and you replace it, hey it's cheap and think of it as preventetive maintenance.
Jake

Thanks for responding, but actually what happens is, again, normally you turn on the air, the compressor engages, radiator fans kick on, and idle drops slightly. This is NORMAL.

What I am experiencing is - Turn on the air, inside blower turns on, but compressor does not engage. Sometimes I have to drive about 10-15 minutes, then the compressor will kick on, and work normally the rest of the time.

[MagicRat]

Originally Posted by Milkman00

Thanks for responding, but actually what happens is, again, normally you turn on the air, the compressor engages, radiator fans kick on, and idle drops slightly. This is NORMAL.

What I am experiencing is - Turn on the air, inside blower turns on, but compressor does not engage. Sometimes I have to drive about 10-15 minutes, then the compressor will kick on, and work normally the rest of the time.

Low freon level will prevent your a/c from working.
There is a pressure switch in the system. If some freon has leaked out, this pressure switch will prevent the compressor from working at all.
This is to protect the compressor, as a low freon level will harm the compressor if it was to work.
It could be that either the freon level is a bit low or the switch is malfunctioning.

[Milkman00]

That makes sense. Where would this switch be located? Inside the compressor or somewhere in the line?

If it is IN the compressor, that is probably a bad thing as it is probably expensive to replace.

[MagicRat]

Originally Posted by Milkman00

That makes sense. Where would this switch be located? Inside the compressor or somewhere in the line?

If it is IN the compressor, that is probably a bad thing as it is probably expensive to replace.

Usually its on the 'low pressure' line near the compressor, but its usually screwed into a hard aluminum line, not the flexible line. But it varies, depending on the car. Sometimes unscrupulous used car dealerships would throw in freon and bypass this switch with a jumper wire, allowing the compressor to come on and cool the car, long enough for the buyer's cheque to clear.
But this will eventually damage the compressor.
Also, dont remove the switch itself. All the freon will come out.

[sierraxr7]

I am new to this forum messaging thing so please bare with me. I am a new owner of a 1990 Mercury Cougar XR7 Supercharger. My air conditioner needs recharging and my ? is: It appears no power is getting to the compressor could this possibly be related to the pressure switch that you mentioned? Secondly, if it is can the switch be turned back on or does it need replaced? And Last of all, do we need to add the freon first, will it make it engage? I live in a very hot climate and a/c is a must. I appreciate any info you can provide. Thanks.

[Brotherssis]

Did you find out what the problem was? If so, would you mind sharing? My 2000 Altima SE is doing the very same thing. Thank you.

[Milkman00]

Originally Posted by Brotherssis

Did you find out what the problem was? If so, would you mind sharing? My 2000 Altima SE is doing the very same thing. Thank you.

Nope - I will be taking it to the shop soon, as I can't take it any more. I got someone telling me it is the Compressor, and those go for $1200 from Nissan (ack). I will be bringing it to Nissan soon to find out what the problem is.

[eckoman_pdx]

I see you've had this problem for a little under a year. Let us know what the problem is once you find out. You could try a junkyard for a compressor if yours is bad (since $1200 is a lot).

www.car-part.com

[sierraxr7]

It was my A/C clutch that was bad. I replaced it.

[Milkman00]

The problem that I had was a bad Thermister within the Evap. coil. It is now fixed and running great.