I feel like i chase myself around in a circle on this one. So heres my update on the situation, Have i gotten anywhere? not really, but figured out the problem more. Doesn't have much to do with engine heat. I've removed the electric fan and replaced with my stock for the time being, and everything was fine as i said. Than i noticed i had nothing on, Headlights on - volts drop a bit.....blower motor on full- drop even more....radio on- down a bit more.....so by this time the voltage is just a bit above 12V, and this is without the e-fans So i decide today i'm going over, adding another few gounds in places and right off the alt. aswell put a new power wire off the alt and clean up some of the other parts.....well it may have helped a small bit, but still same problem.....perhaps the alt rebuild i had trusted in isn't so great.....or...calling for a 3g upgrade perhaps

 

Go back to parts test place with fresh charge in battery and ask them to test the stuff again. If you have replaced the fusible links/found good, a worn split ring in the alternator can drive one nuts with on/off charging with bad brush contact when alternator warms up. A test for a few minutes should show intermittant alternator, and load test should pick up a weak battery cell. Main battery cables do get corrosion in them at the crimp terminal ends and current flow heats them up and bingo no current flo. A test of them too. Your test charging voltage should be +13.7 volts. Systems don't charge with as high a voltage as in the past. More control of voltages with ECU's now. If you find no problems look at your fuse box and GEM for corrosion from water leak. You will see blue green corossion or rust on them. They are bad if that way. If there is no power to the small wire or connection is poor where it plugs into the alternator, the alternator will not energize and charge. Here is where another fusible link wire is.

 

Thanks again papa tiger, I shall be trying everything you mentioned over the course of this week and i shall see what i fined. I have the alt back off now just need to take it over to the tester, I also have a brand new alt. Harness For our 72 maverick we wont be using and it looks like it may adapt to my bronco, Thus should eliminate that as a problem.
Now another question you may have an answer to, i had a 3g alt kicking around so i decided to see what would happened if i tired the swap, got it all on and wired, works great, but when the idle drops low the voltage starts to jump back a forth 12-14 than back up and down and headlights dim etc. So i thought maybe the pulley was to big, swapped lower pulley's problem remains. thinking the alt i had kicking around maybe no good.

 

Voltage will drop off coming back to idle say 650 rpm when warmed up. With cold idle warm up voltage should hold at or near 13.7 volts and alternator should charge +30 amps steady until battery is built up and start kicking back to what ever the load is, say 10 amps with head lights on. Home Depot sells a DC amp meter VOM for about $125 that is the handiet tool in the tool room. It just clips over the cable and reads out positive or neg biased amp flow. Great for alternator starter battery amp draw diagnosis. Make sure it says AD/DC amp meter on it. They also sell only the AC type. No good for DC Amps readings.