ryangore86

Mercedes c300 2010. Ac light blinks then powers. Did have too much refrigeration but now normal level. Suggestions on what could be the issue?

cvx5832

Need more context. What were the symptoms before you added (and overfilled) with refrigerant? How did you determine "normal level"?

ryangore86

I bought it in winter so I didn’t realize it wasn’t working. When you press the AC light, it blinks 3 times then stops. It only blows hot air. Tried to add refrigerant with a can from the auto parts store. Showed was in the red so I let some out to regular level. Checked fuses. None blown.

cvx5832

Those gauges on AC cans are never accurate, have no context to ambient and not calibrated to whatever lowside pressure MBs are spec'd to. That said, based on the thread below, looks like you might still be under (or over), or some other component that's still broken. You'll need to scan codes from the HVAC module.

https://mbworld.org/forums/e-class-w...ditioning.html

ryangore86

I bought a scanner so waiting for it to come in to read the codes. Hoping for more insight then

cvx5832

In the meantime, it wouldn't be a bad idea to get a good baseline on the refrigerant. Have an evac and recharge done at a credible AC shop, the capacity is on a sticker under the hood, and the ones that fill by weight (vs pressure) will only charge you for the gas differential. I do all my filling now, but the last time I did it was around 90 bucks.

TimC300

Years ago I had a Grand Cherokee and decided to charge the ac. I put a can in with just the hose, no gauge on it, and figured that would be good. But then the ac would just cycle on and off constantly and no cold air would come out the vents. I then bought an ac can with the gauge to check and it was way over filled. I let it out until it was back into the green and it started working properly.

Thats about the extent of my ac experience. I learned to not be cheap and buy the can with the gauge.

I looked in my manual under refrigeration and heres the page: