Do those Automobile A/C Additives Really Work?

[Zeroed in]

IDK if the Enhancer stuff actually works for making it colder? It did get pretty cold with 24oz of freon (needs 32oz total) in it. After adding the last 8 ounces, didn't seem to help get any colder. Hopefully it'll help with the internals for compressor longevity.

 

[DustyDog]

My trick for setting charge level on a clutch-cycling system... and of course I always have high/low gauges attached to watch for any anomalies, and usually a low shop fan blowing into the condenser:

At 2000 rpm, with the fan on high, the compressor should run continuously... never cycling. If it does cycle under those conditions, the charge is too low.

At 2000 rpm, with the fan on low, the clutch should cycle fairly rapidly... every 5 seconds or so. If it doesn't cycle at all under those conditions, the charge is too high.

The rapid cycling is why I never run my fan on low: If it gets too cold in the car, I turn the compressor off until I need cold air again.

Of course, ambient temp comes into play as well. The above would apply in the 75 - 85 degree range. However, at 50 degrees, it may be OK to see some occasional cycling on high fan (maybe every 20 - 30 seconds or so), and at 100 degrees on low fan the cycling interval may be around 10 - 15 seconds, for example.

If the system is functioning properly, obviously you can get a proper charge level with no gauges via this method in a pinch.