We are at our wit's end trying to get our 2005 Suburban starting consistently again.

• Have replaced the alternator and battery but it is more complicated than that.
• Also, cleaned the PCM. There really wasn't much corrosion present. That seemed to get the burb starting correctly for about 1 day.
• Tested the following grounds that seem solid: negative battery to under driver side radiator, ground to hood, ground to back of engine (large braided ground wire). Are there other ones?
• Replaced fan assembly and related relays. That was definitely a misdirection and poor $ spend!!

I don't know if I have a hard to locate parasitic power drain or possible just a bad PCM. That sort of feels like the problem but would like to validate it before replacing. Maybe a squirrrel got under the fuse box and gnawed on some of the wires....hope not

I am new to the forum although I have owned different 3 Suburbans since 2004. Kind of speaks to their reliability since I am just now on the forum for help. Also, my son is a young car mechanic now so we have fun tackling these things DIY.