got my truck back this mornin, shes PURRIN like a cat thats had too much cream. at idle, in the cab, you can barely hear the engine, its so smooth and quiet. cant feel it either. yet u can tell its got power, get it above 3000 and off it goes! i cant believe the difference. problem was supposedly a clogged radiator and no fan shroud. mechanic told me he should be charging me for the head, cuz it wasnt a machine shop error, but hes not cuz hes a nice guy. (not that id pay anyway, engine has a warranty) owe another 500 on the radiator and fan shroud... tempted to not pay, cuz i think its just him tryin to get his money back for the head and labor work....radiator was only 5 years old. however, tonight on the drive home, the charge light starts flashing, and the headlights/dash lights would get super bright then dim again, in sync with the charge light. im thinking its the alternator going out.... what you guys think?

 

i would say the diodes in the alternator are going out. either that or the voltage regulator. but yes..alternator is the best bet.

have your battery checked as well as the "field" connection going to the alternator from your ignition switch

 

Also things to check

Could be the belt is loose. Might not squeal but the belt could still be loose

Check that the grounds are all tight if the head was off chances are all the grounds were disconnected .

Check the simple things first plugs on Alternator the battery terminal on the alternator .

When did it flash on and off was it random or was it when you started and stopped or maybe when you hit bumps.

 

randomly. i was purposely hitting potholes to see if that would make it flash (looking for loose connections) and nothing. belt seems tight. im gonna check the grounds here in a minute, and add another 2, one going from the negative terminal to the body, then another from the engine to the body. cant have too many grounds....

 

okay just checked every ground i could find. found 3 of em disconnected, the rest were either dirty or frayed. cleaned em up, hooked up a new engine ground (back of engine to firewall), replaced the ground from - terminal to bottom of block... went from like 4 gauge wire to 2 gauge. replaced from battery to inner fender, and cleaned up random other grounds. its workin BEAUTIFULLY. not drawin nothin anymore. getting the full charge amps now. im still gonna keep an eye on the alternator though... though maybe it will last long enuf to allow me to buy a GM 150amp alternator and the adapter available on here.