1988 F450 7.3L diesel charging system
 

Hi Im helping out a buddy trace out his charging system problem. he has a 1988 ford F450 diesel flatbed tow truck. he already put in a new Alt. regulator, batterys. still does not charge. im looking to see if anyone can help out with a wiring diagram for the charging system.
thanks in advance

Did you check the battery fuse?

HUM did not know there is one Where would it be located

It is in the dash fuse panel in the SD trucks, but in some cars it is under the hood. It is a larger fuse 60A or higher.

thanks JC but thiss truck is a 88 it does not have any big fuse like that. all the fuseable links though were checked. you wouldnt happen to know what the 4 pins on the voltage regulator go to.