Question on AC compressor magnetic clutch

[rayfloyd170]

I want to know the normal behavior of the magnetic AC clutch during initial stepping of the gas accelerator (trying to move from stop and go position).

I just noticed recently (added info below), my AC clutch momentarily dis-engages for a split second or less whenever I step on the gas to accelerate. It engages immediately right after that, and I have no issues with my cooling at all aside from that annoying sound of the relay and fan noise during initial rev.

Added info: I just added an extra 10in condenser fan relayed via compressor magnetic clutch positive line. I also added a manual override switch to disable this extra fan during winter.

I am just annoyed by the sudden AC dis-engagement and engagement for a split second every time I step on the gas pedal in stop and go condition or during idle condition if I rev up the engine. This becomes pronounce or audible because i am using a relay and i hear the relay switching OFF/ON including the condenser fan noise. This behavior is only observed during initial acceleration and never happens at highspeed driving.

I am not sure if this is normal behavior for the AC magnetic clutch system, I tried switching off the extra condenser fan to eliminate it for causing this behavior, but the same thing happens. The AC clutch still disengages for a split second and engages immediately whenever i try to rev the engine from idle or when i try to accelerate from a stop position.

I thought the system is overcharged with refrigerant and cutting off via pressure switch. Then I measured my R134a levels in LP and HP ports and both are good 35psi/230psi at 40-42C ambient weather. I tried revving it up above 3500rpm and only saw the HP max at 250psi that is way below the cut-off. It is also not disengaging during that time which is perfectly normal.

Still puzzled as to why it is behaving this way, I asked a friend with the same Yaris model. I am surprised to know that even his magnetic AC clutch is also behaving the same way. His Yaris AC is stock and no added condenser fan.

Could this be an ECM feature or function to give priority to the Engine during initial acceleration? by disengaging the AC clutch for a split second?

If you can test yours, please let me know. The AC clutch engaging and disengaging is very easy to hear because of the clicking sound.

Thank you.