720 alternator charge issues

[floraljamoke]

Just wondering if anyone has had a similar issue, and knows how to resolve it. 

So a couple months ago my grandfather passed away and left me his old 84' 720 king cab 4wd. he actually ran through the engine and rebuilt it back in the 90's so it runs great when it has a charge. he had primarily used it as a yard truck so the wiring is kind of hacked up in places, and the bed was destroyed. so i threw out the bed to find a bunch of other underlying issues that are totally irrelevant to this situation, but the cab and the frame are solid so im trying to get it running nice so i can drive it for the winter. i threw a new carb on it because the old one had been messed with so many times it was fubar(I got the carb for free anyways). 

Anyways, the truck has always had charging issues since i owned it. He didn't have the money to throw at it, so he parked it last October and it hadn't ran since. like i said tho at this point, if i can keep a charge in the battery, it runs great. but as soon as i take the jumper cables off, you basically watch the charge needle drop until the truck stalls. so obviously i thought the alternator was bad, so i took it to auto zone and had it tested. it gave off no charge, so i bought a new one(had to drive all the way to RI from Worcester), installed it, and same thing. SO then i figured maybe i wired the alternator wrong. turns out i put it back together correctly. There are two wires going into the battery connector, and the connection was frayed so i stripped the wire and soldered on a new connector. still no charge. next i checked the ground connection. it looked solid, but i tried jumping it anyways, and still no charge. traced the two plug wires back into the cab, and the connections look solid, but i cant figure out which fuses go to the alternator. so i hit them all with the test light, and all the powered fuses in the panel tested good. yet again i removed the alternator to have it tested and it tested good. so i reinstalled it and same problem.

SO im not sure if its just me, but the logic is escaping me. there is an extra terminal on the alternator marked "P", but i was told this is for an electronic choke. Input would be much appreciated, thanks. 

 

[datzenmike]

I would look at the fusible links attached to the positive battery terminal. They are about 4" long with connectors on each end so they can be removed and replaced easily. There should be three, two Green and one Black. If one or more appear melted or burnt they probably are.

 

Does the red charge lamp come on when you turn the ignition to ON?

 

 

I hope you kept the old alternator because one.... if the original it's far better quality than the one you just put in. Two it didn't fix the problem so maybe it was something else and this alternator is also no good so now two things wrong. The crap they sell as 'rebuilt' are practically worthless today and are more likely than not to be 'bad in the box'.

[floraljamoke]

I would look at the fusible links attached to the positive battery terminal. They are about 4" long with connectors on each end so they can be removed and replaced easily. There should be three, two Green and one Black. If one or more appear melted or burnt they probably are.

 

Does the red charge lamp come on when you turn the ignition to ON?

 

 

I hope you kept the old alternator because one.... if the original it's far better quality than the one you just put in. Two it didn't fix the problem so maybe it was something else and this alternator is also no good so now two things wrong. The crap they sell as 'rebuilt' are practically worthless today and are more likely than not to be 'bad in the box'.

Ill give that a check, thanks for the insight. Ill check on the charge lamp as well, haven't really looked to see if that's on or not. i do have the original, i intend on rebuilding it, but until i have time to sit down at the bench, i have the duralast special  :thumbup: . less than ideal, but it works for now.