alternater wont charge

[codycatract]

Hi, my name is cody. i just bought a 1979 datsun pickup, i put a l16 into it. no matter what i cant get it to charge, new battery and alternator. it gets a current of 14.5 volts come out of the alternator. the little 12v wire and the charge light wire are hooked up backwards, but when i switched them around and it started battery fluid started oozing. anyone know anything sorry if you cant understand this i am on my phone sorry all help appreciated thanks.

[datzenmike]

Cody:

Are you using a stock L16 alternator? They were meant to be run with an external regulator mounted on the fender behind the battery. The '79 won't have this regulator as the alternator for that year was the internally regulated type.

 

Running an externally regulated alternator on an internally regulated system may be the cause of your problems. Disconnect it first and sort it out before the battery is damaged.

[izzo]

On another note, are you SURE the wires were backwards?? I mean were they cut, spliced etc. or stock wiring was still in tact?

[I'm BLUE]

Cody:

Are you using a stock L16 alternator? They were meant to be run with an external regulator mounted on the fender behind the battery. The '79 won't have this regulator as the alternator for that year was the internally regulated type.

 

Running an externally regulated alternator on an internally regulated system may be the cause of your problems. Disconnect it first and sort it out before the battery is damaged.

 

+1 ---> Very good point datzenmike

 

On another note, are you SURE the wires were backwards?? I mean were they cut, spliced etc. or stock wiring was still in very in-tact?

 

+1 h2theizzo

 

Re-Manned Alternators CAN sometimes be a "Dime a Dozen" ( keep installing one until it works properly since they supposively test , inspect , and fix all problems with alternators before sending them to the next dude :rolleyes: ) I have experienced this across a wide variety of brands , no name brands , and a few good ones. Just a thought :) since datzenmike ^^^ is correct on the idea that it should be internally regulated through those years right ?

 

My Internal Regulator wen't bad on my current alternator on my 1990 Ford Ranger ( Charging about 14 volts :blink: , but none the less still charging and I am running a larger battery but none the less will cook it ) , I swapped my "known good spare alternator ---> From a used Junk-Yard motor , and all is good now :cool:

[codycatract]

ya it is an internal regulater its a 73 motor and alternator the plug that goes in the back those wires were back wards. so i switched them to how the wire diagram said it was suppose to be, and started it and it was chrging like 16 volts then battery started leakin. think its just bad regulator? o and also when i have it hooked up running 16 volts it ran like crap i think thats just because the electric fuel pump got to uch voltage

[FoxyRoadster]

did you unhook your battery when you changed the alt? if you did you might double check that you hooked it up correctly.

[codycatract]

ya its all hooked up correctly i was workin on it for hours. i think it was probably the regulator, so i when and traded alternater in for new one so ill see if its it if not ill just put chev one wire in it

[datzenmike]

ya it is an internal regulater its a 73 motor and alternator the plug that goes in the back those wires were back wards. so i switched them to how the wire diagram said it was suppose to be, and started it and it was chrging like 16 volts then battery started leakin. think its just bad regulator? o and also when i have it hooked up running 16 volts it ran like crap i think thats just because the electric fuel pump got to uch voltage

 

The plug in the back of the alternators are the same for all years and for internal and external regulators, so the wire can't be backwards unless someone cut them.

[codycatract]

ya pretty much every wire has been cut, i bought someone elses problem big time. according to the wirediagram for 73 and 79 they were backwards, but when i hooked them up the way it said it just over charged bad. so i think its the alternator. i eliminated everything lol, its all it can be

[I'm BLUE]

ya pretty much every wire has been cut, i bought someone elses problem big time. according to the wirediagram for 73 and 79 they were backwards, but when i hooked them up the way it said it just over charged bad. so i think its the alternator. i eliminated everything lol, its all it can be

 

:blink: :o That Sucks man ! Previous Owner did a :no: to the wiring

[banzai510(hainz)]

Datto 510, His buddy and I pulled my 521 motor out to swap a trans. Put motor back in then started the truck find out I had the batt cable loose. After git it started noticed the alternator was putting out alot of voltage. Was reading abnormal on my diaode cker. So I then put my lights on and heater and it still read over 15volts. Then I know I popped the volt reg. Swap another External VR and was good.

 

Your probably have a unreg 120 cycle 16-17 volts . zthis will cook the battery and ooz(batt acid all over) and bulge the battery. I know I had a bad VR and the truck was running about 15volts to slowly cook the battery.

 

even 14.5v is getting close on the high side

[codycatract]

ya i heard 13.5 to 14v is good 14.5 is pushing it but will still work. i made my 1 day old battery ooz, kinda pissed haha. well thankls for the help guys, going out right now to swap alternator and hopefully this will work. now you know how on the plug there is the 12v wire (wr) and then there is the little bigger wire that goes in cab?do you guys have the bigger wire on the bottom of the plug i think its labeled n?