ok,heres a fun one for you guys
i knew there was a 100 amp 12si i just couldnt find it,turns out 87 camaro 305 hipro and some others around that year,so i got an aftermarket 150 amp alt,vbelt
start it up and it squeaks ,hit the switch to charge depleted house battery and it howls,smoking belt howl,worthless
but in the late 80's gm has a serpentine water pump/alt but keeps the vbelt for the power steering so simple pulley change,i do it,87 camaro among others around that year,ebay,bolts right in
serpentine belt protests and chirps
it was the frozen fan clutch the whole time,the fan is a major drag on the system,tex2sturgis was saying on a big rig the fan can take 1-200 hp to run
replace fan clutch and all is good,thought about going electric fan but electric motors go out at the funnest times
