A/C problems.... been gased twice - checked by electricians.

[beaver700]

Gday all,

For those with any experience in the zook A/C field, I am having serious problems with my air conditioning...
I have wasted hundereds of dollars seeing autoelectricians, and A/C people, but never have got it working...

It may be a simple problem, but the autoelectricians claim they cannot find any wiring diagrams, hence no solutions...

First of all, when the A/C button is pressed, the compressor and condensor fan do not work, on following the wire through the car, I could not find any fuses in the fusebox!!!

Second problem is that when I jumped the compressor to the battery, no cold air came out of the vents regardless, keeping in mind that I have got the condensor chemically cleaned by ratrad...

Does anyone know anything about this field, or experienced similar problems.... if so any help would be greatly appreciated...


Thanks for your help for so many things, and this issue as well!!!


Cheers

[Arcadion]

Heya, not sure if this is gong to help much, but with most cars out there, the operation of the ac is determinded by the fan speed resistor.

Not only does it determine the speed that the blower fan runs at, but in many cars, if it's not working correctly, the clutch on the compressor will not kick in either. Is the blower on yours working? And if it is, does it work at all speeds? When you said that you jumped the compressor directly to get it running, was the blower working as well?
The fan speed resistor is -usually- located near the evaporator, because it gets really hot.
The evaporator is inside the airbox under the dash.

Once you find the resistor, there is usually a plug with one wire into the plug (full load/speed) and one wire out to the blower. there are normally 2 or 3 extra connectors on the plug though, as these connect up with pins on the fan speed resistor. Bridge the wire coming into and out of the resistor. this should simulate the blower on full, ac on.
Once again, not all resistors and setups are alike and I have no idea if sierra's use a fan speed resistor or not, but that is the first thing i would try.

The next thing if the blower is working, is check to see if you have a thermal switch. Once again, when you have found the evaporator, look for a solid wire leading to a small box with electrical wires coming out of it. The solid wire is the temp probe, and the box is the thermal switch. you can use a piece of wire to bridge the to wires together to complete the circuit, and this will bypass the thermal switch. The thermal switch disengages the compressor clutch if the evaporator is iced up. Therefor if it's not working properley, no ac.

It really doesn't matter if the unit has been gassed, and auto leccy's have looked at it, there is no substitute for getting in there yourself.

I fixed up my in laws VW polo after the same situation as yours. Auto leccy's gave up and said it's a fault in the car's computer, take it to volvo for a service, and all it was was the resistor. I spoke to the same leccy's and they wanted to charge me $300 for the part. Jumped on the net and snagged said part for under $50 and put it in myself. no problems.

I'm no expert, but this will give you a few more options to try!

[kimclive]

Hi,

I had a similar problem with my Vitara. The compressor was overhauled by an a/c guy and the system gassed up. "Way you go."

The compressor kept cycling off and then I found ice cold water pouring onto the floor on the passengers side.

I opened up the covers around the evaporator and found it was FULL of leaves and dirt and the evaporator was clogged solid.

I cleaned it all out and blew it through with compressed air (through the radiator-like fins of the evaporator).

Work just fine now.

Cheers

Clive

Yeah. I know it's slightly off topic but it is a/c related tech!

[karmic]

on my '90 sierra with what looks to be factory air thats been decidely non-factory installed.. the aircon wont kick in UNLESS the fans are turned on AND the system is set to RECIRCULATION of the air (and the A/C button is on).

Give it a shot .. it stumped RAC when I got them to do a pre-purchase inspection of the zuke

Kyle

[jabtronic]

Mine doesn't turn on unless its on recirculation either. So I think that's standard

[beaver700]

Hi all,

Thanks very much for your replies fellas. I got a test light today and went through the system. There was no current coming to or from the a/c switch... the condensor fan and compressor wires also had no current. On looking closer at the 'small metal box' located underneath the airbox with wires coming out of it. One or two of the wires had no current...

Also does the little blue a/c button on the sierra dash have a little light?, if it does, the light does not glow when pushed. Could this be a faulty switch or perhaps one of the problems you have suggested...

Arcadion, thanks for your reply Yes the blower does work when the compressor is jumped.

I couldnt find the pressure switch on the system either! Its suppost to be on top of the reciever drier, but aint there!!!

I definately will blow the condenser out and try the other methods sugested,

Cheers guys, thanks for your help,

[Arcadion]

I just re-read your post and noticed that you said you couldn't find any fuses in the fusebox for the ac...
Was this the fusebox under the drivers' dash, or the one in the engine bay in front of the battery?

My ac fuses are in the engine bay, but I don't have ac, so they have no connector.

If you have no power getting to the switch, and therefore no power getting to the other components, I would go back through and check all wiring from that fuse back. If you need a wiring diagram let me know and i'll post it up.

[beaver700]

Thanks for your reply,

Yes there is a fuse box but no fuses for A/C. I cannot locate the fuses for the a/c system anywhere!!! Does anyone know where I could kind them?
A wiring diagram would be great!!! Thanks for your help.

Ive got a suzuki sierra 86 model.