87 Charging system won't charge

I have been tearing my hair out trying to get this problem resolved. My 87 burban will not charge. I've replaced the Batt. and Altornator. I need to some help. I need some ideas on what to do. I've pulled the new alt twice and it test good. The batt test good also.

Is the plug that goes into the alternator burnt or corroded?? open the plug and check it should seperate i had the same problem with my 87 burban and untill i opened the plug at the alternator it was burnt and melted but u could not tell from looking at the plug.

Also check and make sure the alternator belt is tight that will cause a problem

The plug is good and the belts are tight.

so how do u know the alternator isn't charging? what is happening ? ur voltage at the batt and off the back of the alternator ?

The voltage on the back of the alt is the same as what is in the batt. I can't get 14volts out of the battery, but the Alternator tested good at 2 different stores.

what is the voltage did u pull the alternator or test in the truck? and was it under load? i kinda sound like their is a bad connection between the alternator and the batt or some where on the charging system. let me know

If I remember correctly,there may be a fuse that is used for the charging system.Check to make sure it has not blown.What is the voltage at the smaller wire that feeds the field when the key is turned on?If no voltage present,that could be the problem.You could put 12 volts to the field wire and see if the alternater starts working.Hope this helps.
chuck's

Hmmm...Not charging...parts good...If applying voltage to field wire does the trick, I would start looking for a bad ground / connection, beginning with the starter. Truck will run w/o this wire, but won't charge.

Well the problem is fixed. I had to take it into the shop. It was great , they told me it had the wrong alt in it. Well for the 87 I have found out that sometime they started putting TBI in and had been using the 88 wiring. Really stumped them for about a day. So thanks to everyone for your ideas. Thankyou