need some help I've replace the battery and alternator and when the truck is running the alternator is not charging it steadly drop volts while running but when the truck is off but the switch is on the volts stays the same i got a 1987 ford ranger 2.9 V6 Thanks to anyone that can help really dont know what else to do or replace

 

i don't understand. you switched your alternator? was the alternator new? what kind of battery did you buy?

 

yes the alt was new and i bought a battery from advance that the truck call for the battery is around 6 months old then the alt quit charging so i replaced it with a new one and it worked for about 2 months and then it quit working so i put another one on today and it still wont charge i dont what else to do i dont know if it is some sort of relay that is keeping the alt from charging

 

Remove and clean all the ground connections , esp. from battery to engine.

 

try replacing the alternator again, i know its pretty ****ty, but its happened plenty of times on hear where people got a new alternator and it was bad when they got it,you can get bad parts

 

I agree, i know its new but it sounds like your alternator isn't working,

 

yeah personly i'd get it checked were you bought it and if it tests out bad, then ***** them out like crazy, till they replace it

 

ok, i can understand one alt being bad. But 4? seems like there is something else going on.

As ortech stated, Check and clean all connections

 

Check the wiring going to the regulator. If the key on voltage is not there, it won't turn on the regulator and you have no charge. It should be the green wire if I remember correctly. The yellow one should have constant.

 

I just wanted to tell everyone thanks on their input on my problem and I finally got it fixed today took the alt back and it checked out fine so i put it back on once again and started chasing wires from the alt back and notice that there was a cluster of wires on the drivers side that didnt look right so i pulled them and they was stuck to the fender and there was a burn spot where a wire has been arching off and there was the problem the wires was melted together and one was broke so i fixed that and the alt started charging so once again just like to say thanks to everyone with there input