Alternator not Charging any Help!!!

Alright here we go!!! Doing a LT1 swap in a 1990 C1500. This thing has nickle and dimed me to death already and I am sure more to come! So here it goes the alternator is not charging the battery, we have tried to run a 12 volt lead tried to troubleshoot myself and no luck! I ran it over to the shop and the mech. there told me the computer is not sending a signal to the alt. so he has advised to have the alt. changed over to a 1 wire alt. problem is I don't remember computer having anything to do with the alt. but it has been awhile I can't remember. By the way motor tranny and computer is out of a 93 Z28!!! I have tried to contact the local elec. shop and now he has to call his supplier and confirm the nessecary procedure for the alt. conversion being its a new style????? I give up I am confused now anyone can help me out I would appreciate any info!!!! And anyone have an idea what a general cost would be to convert this alt. I have no clue right now and just want to make sure I am not getting the shart here!!! Thanx

I'm doing a 95 LT1 in a 70 C10 right now and the alternator just had 1 wire to excite. PCM has nothing to do with it and mine is working fine. My engine is from a Caprice, but I think it has the same accessories as the F-body.

I think the two are different. Everything for my motor is a 93-94 ONLY !!! LOL I found out the hard way already! Funny you have a 70 I have a 68 Fleet Short with a 6.0 love the c10's going fuel injected now sooo much more reliable I had a 468 BB 871 Blown and definately not DD worthy LOL Thanx for the reply PitchBlackC3

It's not my truck, I am building it for my cousin. Turning out really sharp. Got a little bit of wiring left, not much. Vintage Air unit on the way. This was his grandpas truck that he left to him, a tree fell on it about 7-8 years ago, but now she is better than ever. Frame up, everything new. Rear mounted tank, hydroboost brakes, aluminum radiator with e-fans. Started as a cab replacement and got a little out of hand.....it will be super nice though.

Good for your cousin when the vehicle has history it's always more fun working on rides especially when it's done my 68' was given to me by my Great Grandfather I played in this truck as a kid and he would take me for rides around the block until I fell asleep I cherrish my c10. Good luck to you two in the build hope everything runs smooth!

Alright peeps problem solved after another day of troubleshooting I finally gave in. Ran the Alt. to the Auto electric shop 40 bucks and exactly 1 hr. later I have a one wire Alt. hooked up works great charging my battery at 14.9 volts!!!!!! No more hesitation in the motor idling good finish up ac tommorrow and I will be rollin once again! Until next time!