Broken aircon on 2.5 diesel

[Evert]

Guys

I've got a diesel cherokee and my aircon is busted. It does not do a thing. I don't hear the clutch engage or any other sounds when I turn it on or off.

I've checked the low pressure swith and I've bypassed it, but still nothing.

I checked the connections on the compressor and something strange is going on here.

There are two connections to the compressor. One green and white one that sits on the top of the compressor (I've marked it as number 1 in the photos) and one that connects to the outgoing tube of the compressor (marked as number 2)

Number 1 have a voltage of 13 Volts on the line when the engine is running .

Number 2 has no voltage on the line coming in and there is no continuity over this line. The tube side has a resistace over it of around 1200 Ohm.

Anyone know what the hell is going on?

[Deezelweazel]

Get the aircon serviced. It shuts automatically off when low the internal pressure is low.

Anything else is a waste off time- if refill fails switch to the mexican aircon and get rid off the heat exchanger in front of your radiator. Your engine will say thank you.

[Mudmonster]

silly question but is there definatly gas in the system?

[Evert]

I've got no idea if there is any gas in the system. It didn't work when I bought the car and I am only just now looking into it. Is the a way to check this myself?

I thought I could short out the low pressure switch so that I could check if the rest of the system still works. I don't want to waste to money on taking it into a shop and getting it regassed just to find out that the compressor is buggered.

With everything else that has broken down on this car I am not very confident in anything operating the way it should.

[Mudmonster]

they way i check is screw one of the caps of the pipe there is one on thye pipe along the top of the fan shroud, get a long thin screw driver and push the value in for a few seconds approx 5sec, it will make a hiss like a letting your tires down, if it doesnt make the noise for the whole 5 secs your out of gas,

avoid breathing in the gas as well.

it not the correct way to check but at least you dont have to pay for it to get looked at.

how long ago did you buy the car??
the evaporator could now be buggered. mine was not working for 8 months and when i finnaly got it all fixed and gased up the evaporator decided to blow holes in itself and leeked all the gas out about 2 days later. i belive they are a common failure.

the only way to check if its the evaporator is regas it with the UV dye in the system, pull out the fan relay in the bottom of the fan box, get a small mirror and a UV light, shine it in the mirror and look for green glow.
but luckily im good mates with the local auto elec so it cost me nothing to check

[Evert]

Hmm, it's been buggered for over 2 years and god only know for how long before that.

Thanks for the tip, I'll check if it still has any gas and then make a descision of what I want to do.

[del97td]

third pic just above connector 2 is a white block this is a thermal fuse which cuts power if compressor gets too hot (the wire going to this fatigues and breaks stopping your aircon) also on top of the receiver drier is a connector with two wires if you bridge these wires it starts the comp as a test these wires also fatigue or rub on bonnet

[Evert]

third pic just above connector 2 is a white block this is a thermal fuse which cuts power if compressor gets too hot (the wire going to this fatigues and breaks stopping your aircon) also on top of the receiver drier is a connector with two wires if you bridge these wires it starts the comp as a test these wires also fatigue or rub on bonnet

Thanks mate. I tested the voltage on the input wires on connector 2 (thermal fuse), but I get nothing on the line. Should I have a constant voltage going into the thermal fuse?

The receiver drier is the black can looking thing isn't it? I tried bridging this out, but no result.

[del97td]

no constant power only when all criteria are met (air con turned on left of center on switch or defrost mode and the system having sufficient pressure (connection on top of receiver drier))
good luck Del

[Evert]

no constant power only when all criteria are met (air con turned on left of center on switch or defrost mode and the system having sufficient pressure (connection on top of receiver drier))
good luck Del

Ok cool, So I have to bypass both switches to see if it is going?

Thanks Del