[willisodhiambo]

I have a problem I am trying to resolve but can't understand this car's behavior. AC is not working, and I have done some diagnosis, and this is what I know.

1. Replaced compressor 3 times, does not run/engage
2. While filling in the gas, simulated compressor clutch engagement by supplying power to compressor actuation circuit, this seemingly engaged the clutch but.....
3. The filling does not complete!! I expect it to draw in the gas from the low side with compressor engaged but nothing happens.

I have not bothered with the rest of the system as I expect it to be able to fill up with gas when I manually engage the compressor. Am I understanding this right?

[Node]

N43 has a variable compressor which is controlled by PWM signal. Hence 3 wires in the connector! So have you put PROPER compressor AND have you checked PWM signal??? Also have you read faults???

---

P.S. given energizing clutch does not help, it is possible you've put correct compressor but there is no pwm. OR you are energizing the wrong wire (which you need to send pwm on one and power on another)... Well you could put power on control solenoid too for a SHORT period of time for max compression...

[bellphegorus]

there are 2 Types of Compresor in n43, PWM and not PWM which one do you have?

[willisodhiambo]

I think I have PWM (3 wires, Power, ground and PWM). I will test again and see if I get any signal in the PWM line. So it is possible to engage the compressor by supplying voltage but get no pumping because of missing pwm? Interesting.

I did diagnosis and ISTA suggests replacing the compressor. I did notice that evaporator temp sensor reads zero, no idea why. Maybe a faulty sensor. If only there is a means I can test compressor function before these other things.

[Node]

If evaporator reads zero, it could be that IHKA does not allow compressor to be started to prevent freezing. That is definitely a thing to be checked why.

P.S. There is NO "power" in those 3 wires. It's ground, clutch (on/off) and control valve (pwm). Control valve not open = no gas flow. Fuel economy thing. No need to spend much energy compressing much gas if only very little cooling is required.

[willisodhiambo]

If evaporator reads zero, it could be that IHKA does not allow compressor to be started to prevent freezing. That is definitely a thing to be checked why.

P.S. There is NO "power" in those 3 wires. It's ground, clutch (on/off) and control valve (pwm). Control valve not open = no gas flow. Fuel economy thing. No need to spend much energy compressing much gas if only very little cooling is required.

Thanks, I will start with evaporator temp and try figure why it reads zero.