Air Conditioner Capacitor

It has been very hot here recently, with high temperatures above 105 F (40.6 C). Sunday morning, my mom complained about being hot indoors. It was 80 F.  We measured the temperature of the air coming out of the vent, and it wasn't any cooler. We figured out that the air conditioner wasn't working.

This happened just after the roofing company placed netting around the house to protect the windows and AC from falling shingles. Was this a coincidence, or did the netting over the AC restrict the airflow and add extra stress to the system? First we tried turning the AC off for about ten minutes, and peeling back the netting. But when we turned it back on, it still didn't fix it.

The air handler fan and condenser fans were still working, but there was no cooling. I took off the cover of the AC unit and tested the capacitor with my multimeter. It was a dual capacitor 70/5. The compressor part, which was supposed to be 70 microfarads, read 3 nanofarads. The fan part, which was supposed to measure 5 microfarads, measured .7 microfarads.

Once I figured out that the capacitor was bad, the next step was finding a replacement. My dad shopped for a replacement, but everywhere he checked either didn't have it in stock, or was closed on Sunday. Of course we could have called an AC repair place but that would have cost a lot more. My dad ordered a replacement from Amazon, which would take around 24 hours to get here. If the temperature inside kept rising the way it was, we'd probably have to stay at a hotel overnight. So he kept shopping, and finally found the exact capacitor we needed on Craigslist. It was over twice the price of the one from Amazon, but we could get it the same day. We met the seller halfway between their location and ours in a convenience store parking lot (probably safer for both of us because of all the sketchy stuff on Craigslist.)

The new capacitor didn't have the three terminals color coded like the old one, but it was easy to figure out how to connect it. We turned the AC back on, and immediately felt cooler. Now the air coming out of the vent is 57 F. 

About 12 hours later, the capacitor my dad ordered from Amazon arrived. We're not sure if we'll return it or keep it as a spare. It has a dent in it, which probably won't affect the function.