A/C acting up?

[tomcat837]

SO I get in my '99VX and turn the A/C on but nothing happens. I toggle the outside/recycle air lever and it gets it going. It doesn't happen every single time, but one time is too many. What could be happening? Has anyone gone through something like this before. Another thing is the little blue A/C light, the A/C is working fine and everything but the light doesn't come on...

Any thoughts?

Thanks in advanced,

Julio

[MZ-N10]

uhh......the "fan" switch isnt on?
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ChyarasPussy

[rainee25]

Another ??? Why does the AC compressor kick on when you turn the defrost on in the winter? Waste of gas......

Rainee

[MZ-N10]

with the ac on the moisture in the car condenses on teh ac coils because water will condense on watever is cold. the water tat condenses on ur windshield will condense on the ac coils, clearing your windows.
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How To Roll Blunts

[mrtew]

Originally posted by MZ-N10
with the ac on the moisture in the car condenses on teh ac coils because water will condense on watever is cold. the water tat condenses on ur windshield will condense on the ac coils, clearing your windows.

Yeah, what he said... the A/C has to be on for the defroster to take the steam off the inside of the glass. Also you need to run the A/C for five minutes at least every few weeks to keep the seals in your A/C system oiled so they don't dry out.

[tomcat837]

The fan switch is on... when this happens I can turn it on slow and fast several times, but nothing happens until I toggle the other switch back and forth...

[PeteVX]

if the a/c works when you fiddle around with it its a good thing that means you have adequate refridgerant and dont have a leak and the compressor works! and is more than likely a bad electrical connection somewhere.
I havent looked at the vx a/c system but many vehicles also use vacuum to switch the blend doors and temp control in the HVAC plenum so could be a vacuum line leaking. I'd start by getting to the back of the heater/ac controls and work back through there.

If the a/c is poor even when it does work, try and borrow a set of R134 manifold gauges hook them up, (the high and low pressure sides have different size fittings so you cant screw em up) then if the system has been at rest or not used for some time, both guages should read approximately the same and with R134a will read in psi approximately what the ambient air temp is.

If its 70 deg out and you read 20psi on both guages you have lost refridgerant, start looking for signs of oil around the piping, connections etc.

Does the compressor kick in? again with low refridgerant the low press cut out will prevent the compressor from starting.

As for the a/c on defrost ....here's the techpoop... your windows fog up because of high humidity in the air and generally cooler temperatures, outside. The dewpoint temp is the temp at which condensation will be drawn out of the air and will settle on a cool surface, ie when the air cannot hold any more moisture. If you bring a cold beer out of the fridge on a humid day, it will instantly be covered in condensation because its surface temp is below the dew point temp of the air.

Soooo, the air passing over the evaporator coil which is very cold and is always going to be below the dew point temp will condense the moisture from the air inside the vehicle onto the coil and therefore clear the fog from the windows!!

Brilliant innit?

[Tiger66]

Recent problem with my AC system. The blower (fan) did not work, so it seemed like the AC wasn't working when it really was - just could get out. The problem was the blower resistor block (thing that controls the various speeds). Part 8972345450. maybe that's your problem too. (broken connector, maybe it's a cheaply made part)

[PeteVX]

tiger...same thing happened with my jeep, the fan would only work on high speed, the lower speeds use resistors to lower the voltage and speed, but being resistors they get hot so have a thermal cutout fuse mounted above the resistor block that blows when they get too hot to prevent a fire and stops any power going through the resistors.

I took the resistor block to an electronics supplier, they gave me a new thermal cutout fuse for 97 cents that crimped in and everything was fine again. (the dealership wanted $75 for a new resistor block)

One of those wierd things that if it happens again you know what it is

Pete

[Heraclid]

Thankfully the worst I've experienced is that the blue light on the on/off button went out - system still works fine. Annoys me a little, but probably too much of a pain to fix.