Troubleshooting Climate Control on 1999 QX4

[restes1989]

Hey Gang,

Been lurking here for a while and have approached something I can't seem to fix by tinkering with my limited auto knowledge.

My climate control appears to have 2 problems:
It won't send signal to the AC compressor relay and it doesn't seem to adjust the air draw from hot engine air to cooler air based on the temp. settings.

My climate control will change modes and adjust the fan settings.

My AC compressor will turn with the belt when I manually engage the relay so I'm thinking the issue here is a signal. I've tested the relay and it should be good.

I've never dealt with the climate control system so I wanted to pic your brains before pulling the console again.

Much Thanks,
REstes

[yeldogt]

The compressor clutch will not come on if the system is low on refrigerant .. I don't understand the other problem from your description. The system has a pressure (low) cutoff sensor.

You best bet is to have someone look at the refrigerant level -- it needs to be correct. if you have a leak it needs to be found -- and properly filled. If all the refrigerant has leaked -- you may have to pump it down and do a bit more work.

[restes1989]

I was thinking that those pressure switches lie between the compressor and the relay in the relay box under the hood on the drivers side. I manually engaged the relay and the compressor came on so I was expecting those switches/levels to be good. I may be wrong in this understanding.

I expect my main issue may be stemming upstream. My climate control system doesn't activate the AC and also doesn't switch from pulling hot air off the engine (for heat) to pulling cooler air (such as cabin air). It is stuck on pulling really hot air regardless of the temperature setting.

Does this help you understand my issues? Thanks so much for your interest and help in this.