SD7V16 Control Valve 1157F Compressor

[Citroënbender]

https://www.aliexpress.com/item/3PCS-Automotive-air-conditioning-compressor-control-valve-frequency-valve-solenoid-valve-for-SANDEN-SD7V16-SD7V12-SD6V12/32817202862.html

This is the closest replacement I can find for the OEM fitment in an 1157F SD7V16. I measured an original's dimensions to determine that aspect.

[Citroënbender]

For those lacking reading (research) ambition, this valve greatly reduces the "pumping" effect of the AC compressor without actually unlatching the compressor clutch.  Result is less driveline shock, less belt and pulley strain.

Problems arise when the control valve pressure drifts away from spec; how many times can you compress then relax a small internal spring before it loses some tension?  The result is a compressor lacking efficiency, causing a loss of cooling ability.

And then if you put the windows down instead of fixing the AC your interior gets road soot through it and the driver's window regulator fails.