A/C does not turn on

Welcome to 2CarPros.

First, you are absolutely no bother at all. I'm glad you asked.

Have you checked to make sure the system is charged? If it is too low on Freon, the low pressure switch won't allow the compressor to engage. Thus, no power to the compressor.

Take a look through this link.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Here is a link showing how one is charged:

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

If you have an AC manifold set, check the pressure on both high and low side. Take a look at this link. It shows the gauges being used.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Let me know what you find.

Joe

Sorry, it took awhile to test everything.
I started from AC clutch. There is a good ground but no power. I plugged the compressor directly from battery and it worked.
Then I moved to relays. I test all of them, bought a set of new relays and replace them. No effect.
I test voltage and resistance in each relay port and only one has weird numbers (ac clutch one) see attached picture.
Then I took the relay and connect AC clutch circuit and AC started.
My thoughts that the problem with ground. What do you think?
Last thing I wanted to check is the ground wire from ECM but cannot find arrangement of wires so I can find the right one. I would be sad if the problem in ECM.

Sorry, I said “ground wire from ECM” but I really mean power wire which goes to ACC so I can ground it and see if AC will start. I think in this case I will confirm that computer does not send the ground on AC relays.

Welcome back:

If you take power direct to ground, it will pop a fuse or cause damage. Is that what You mean?

Joe