Please help me save my green machine

[adambombsaway]

Thank you for your response seems the voltage issue is the least of my problems now. Yes I went to pep boys to have my coolant system flushes and they wouldn't touch it due to the antifreeze looking like "chocolate milk", and said possibly have a blown head gasket which I don't see very likely because the oil is always clean not "milky" when I change it and the engine temperature never reads even 1/2 way between L&H it's always barely above low. The only physical issue is the extremely loud screech and the voltage dropping way down to nothing I'd I go from stop to go with my heat on, but that stops as soon as I turn my heat off and back on once I reach about 10-15 mph. From my very uneducated auto repair knowledge a bad head gasket or cracked head ALWAYS leads to over heating. Am I wrong here? Should I flush the system myself? I bout some head gasket and block repair but I won't be able to use it because I have to allow the initial flush dry for 12 hours which won't happen in 0-10 degree weather. So I was thinking maybe just wasting a bunch of antifreeze and flushing it a few times myself. Could I cause more damage? I mean my explorer is absolutely immaculate inside and out. IDK WHAT TO DO HELP ME

 

[Gadget X]

The loud screeching and the voltage dropping sounds to me like your belt is slipping. Do you have it on defrost setting when this happens? Asking because the defrost setting uses the ac compressor, which puts more load on a possibly worn belt, leading to slipping and screeching.

 

[adambombsaway]

Yes usually floor/ defog. My biggest worry is the "chocolate milk" coolant in the radiator. The truck is immaculate in and out except apparently under the hood.
Thank you for your reply.