Have a 1998 Z71 K1500 and it seems to be a lemon always something going bad on it . Current problem when I turn on the blower fan for air the amps drop from 14.5 to 10 Amps . Alt. is new. checked ground straps ,and fan control has all four speeds when switch is turned on, Fan works and has no noise etc . Forums say Fan resister but fan has all the speeds working and fan works with no noise . With a bad Fan resister would only have the high speed working . but all the others work fine . has me stumped .

 

This vehicle is on its second engine due to bad lower intake gaskets and the loss of coolant .And it has a new atl. a new front axle carrier ,seal went , New wiper motor and Fuel pump and fuel regulator . Might have a new vehicle in a few years

 

Thats volts not amps.Is this when the truck is ideling or moving down the road?