Air con problem

[Jordy909]

I have a 2010 ve
Air con pump won’t kick in

It has had the engine replaced and now aircon dosnt work I had it at a mechanic today he checked pressure and was okay

He then bypassed the pressure switch to try get the ac module to start pump

He then told me the ac module wasn’t getting an signal

Any ideas

 

[Skylarking]

As a general comment, If the ac system is fully charged, then the high (over) pressure and low (under) pressure sensors won’t see problems so will allow the compressor to kick in if it’s commanded to do so by the ac control (hvac?) module.

Basically, ac pressure switches are used to protect the ac system from over pressure and under pressure conditions that can damage the compressor and/or other components.

For the compressor to kick in, it requires that it is commanded to do so by the control module and the pressure interlock feature not to inhibit the compressor from starting … that means means the controlling module must be getting the correct signals (inputs) so it can command the appropriate signals (outputs) …

So as some VE’s had both a pulley clutch as well as a variable volume compressor, those types need wiring to activate the clutch pulley (so the compressor can be turned by the engine) and wiring for the PWM solenoid (so that the compressor volume can be controlled).

Basically have a look at the compressor to see that all plugs are indeed connected and there are no loose connectors floating about the vicinity. Hopefully the ac compressor wasn’t changed with the engine and the correct type is fitted so it’s just a forgotten plug that wasn’t pushed home.

Oh, and if the ac was working before the engine swap, it’s an issue for the mechanic who did the engine swap to sort out. Could be pinched wire, squashed ac line or anything really.

As a last comment Adairs is (was) a great resource for ac related technical bulletins but the link I had doesn’t work any longer Another great resource is the ve commodore factory workshop pdf manual that is floating about the www (a link can be found within JC’s) and that manual has all the specifics you’d need

 

[shane_3800]

Your so called mechanic sounds like an idiot.
I'm pretty sure these are a continuously variable swash plate design for one.
For two if the controller won't engage the swash plate then the pressures can't be checked, you can't know if they're good if the pump isn't working.

You need to check with a scan tool if the control module is requesting the pump to make more pressure, and then check that against what the pressure sensor is seeing.

That is about as far as you can go until these things a verified.

 

[Jordy909]

Your so called mechanic sounds like an idiot.
I'm pretty sure these are a continuously variable swash plate design for one.
For two if the controller won't engage the swash plate then the pressures can't be checked, you can't know if they're good if the pump isn't working.

You need to check with a scan tool if the control module is requesting the pump to make more pressure, and then check that against what the pressure sensor is seeing.

That is about as far as you can go until these things a verified.

Was done before I brought the car the mechanic I took it to today said the ac module isn’t getting any signal after he put the scan tool on it

 

[Skylarking]

if the controller won't engage the swash plate then the pressures can't be checked, you can't know if they're good if the pump isn't working.

IIR, that’s not 100% correct as the high and low pressure side will stabilise to equal pressures if left alone. At that point the low pressure side can be checked and at a given ambient temperature and gas it does indicate whether the correct gas volume is within the system.

The extra provided by checking the high side pressure is that it checks your compressor can actually squash the gas where the condenser can then extracts the heat at which point the gas turns into a liquid.

IIRC some VE’s had three types of ac compressors.

1. a variable volume compressor using a direct drive pulley (they always turn with the engine and use a hydraulically actuated wobble plat that uses PWM signal to turn a solenoid on and off which varies the wobble plate angle and thus the compression ration/pumped volume of ac gas that is sent through the system)
2. a variable volume compressor driven by a magnetic clutch pulley (which must be activated for the engine to turn the compressor but for gas to be pumped the PWM solenoid signal must also be commanded on how much the compressor should compress the gas)
3. a fixed volume compressor driven by a magnetic clutch pulley (old school simple but less efficient).

OP needs to check with Holden spare parts using his VIN to determine what type of ac compressor he should have installed… and then also check his wiring…

As is, used cars can be modded away from factory so who knows if his ac is standard