When disconnected, my battery will sit at around 12.8 volts. I tested the current draw by disconnecting negative terminal and then using the multimeter in series. It read -1.8 amps, which is a ton. I also tested the voltage after immediately turning off the car. The voltage drops quickly from 14 volts to 10.5 volts within 30 seconds, you can watch the numbers fall.
What could cause a draw this large?
1.8 amp load for a bit might be normal. The battery should be able to withstand that load for at least a day. The voltage going down within 30 seconds means the battery is bad.
Replace the battery first unless you have a power supply that you can hook up to the vehicle for diagnosing.
Yea, like another user said, I should have let all the modules power off before I did the test. My biggest question is why does it only happen in the colder weather.
Electrical problem changing with the weather is really common.
Which would lead me to think alternator, but it had same issue before and after the alternator was replaced
That’s why you should measure what causes the problem rather than just replacing parts.
No I agree. Last year I went thru every fuse in the two fuse boxes and non affected the draw except the power saver fuse, ironically. Even then it was a very small difference
How much was the current draw then?