In my 1985 f150 i replaced the battery,alt,voltage reg, and cleaned all connections. the next day my new battery was dead !! i pulled the NEG wire and checked it with a amp meter.it read 13 AMP.... somthing is draining my battery...i tried the pulling all the FUSES one at a time and nothing ....Could this be somthing to do with the starter ? i even pulled the headlight connector....still nuttin..Whne i disconnect the hot wire to the ALT, the drainage goes away..I took back the alt, they tested it and said it wasnt putting out anything.i got a new one AND IT DID THE SAME THING.....HELP PLEASE !!!!!!

As soon as i plug the hot wire from the ATL, the drainage stops, i have replace the alt twice ( new alts ) and the same thing happens each time.....

 

Do you have a voltage regulator near batt? It could be defective.

 

i replaced the voltage regulator too......the connector was bad so i cut the wires, put new ends on them and pluged each wire on.

 

Moved to proper forum.

 

quote:
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Originally posted by elwaykid
AS soon as i plug the hot wire from the alt the drainage stops....this is the 2 nd new alt that i put in......
i'm pulling my hair out now.....ANY SUGGESTIONS ???
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I am assuming you are taking the heavy output wire off the alt, and your power drain goes away? I would leave it hooked up, but unplug your field connection on the alt, and the stator connection if you have one. With all the wires disconnected from the alt, (BUT the heavy alt output wire still hooked up), and it still gives you 13 amps through the heavy wire, your alternator is bad.

Why are two alternators in a row bad? It's either coincidence, or are you messing with wires while the engine is running? Don't pull the battery cable off with the engine running, and don't mess with any other wires while the engine is running.


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i tried that, still does the same thing.......i didnt start the truck at all......i'm going to try another voltage regulator......

i'm thinking its the alt .(again) but how can i get 2 bad alt's in a row..???

 

Depending on where you are getting them, it is possible. Some auto parts stores do not have a very good reputation on their rebuilt electrical stuff. I have heard of guys getting so frustrated, that they demand a new rebuilt alt be tested before they leave the store, and have had them test bad right out of the box. They don't care, it's your time and labor, and they will be glad to give you replacements all day long. It would be a different story if they had to install them.

 

when i put the 1 st new alt in i took it to AUTOZONE, and they checked it, the guy said it was charging the battery.....BUT the truck was running then.......then the next day , battery was dead, i took off the alt ( after trying evrthing ) and he tested it on the bench, it came up dead......SO he gave me another one, but he tested it first on the bench and it took the load..it did ...so, ..i didnt even install it, i hooked the wires up, grounded the alt and checked .( didnt start truck).......it was still draining the battery...now i'm really pissed, so i installed the alt and tested it again.......SAME THING....

thanks for the input.

 

OK it is possible you have a bad ammeter and or shunt and this is causing you to blow diodes in your alternator or your voltage regulator is staying on. Check the power at the regulator with the key off. you should have no voltage at the ignition or field wire with the key off. The Field to the alternator should also have 0 voltage.

But some 1985 Fords have a built in regulator. From your post I am assuming its an external regulator.

 

I am guessing he has a bad alternator.

 

thanks DARTH VADER, i'm gonna try that later .....

 

I don't understand this concept, but I agree with everything else you said.

 

On an amp meter the power flows from the alternator main cable through either a shunt or directly through the amp meter then to the battery. If you have a bad amp meter/shunt the circuit can open up intermittently and that could cause diodes to pop or even worse, voltage spikes.

Factory wiring on all makes sucks.

 

Ok, I get it now.

 

well, after a few days i narrowed it down to the wiring ....duh.
the F WIRE from the voltage reg to the alt i was thinking was bad. Then i got a call from a friend saying to take it to a auto eletronic shop down the road..Well, i caved in and took it there. I explain evrything it did to the guy, he called me back a few hrs later....... it was the wiring between the voltage reg , alt and battery.!!!!!!! no kidding i said....some how it was OVER chargeing arround 17 volts....almost burned up my new batt..
i'm picking it up today,All new wiring and it only cost me 150.00
just in time to snowplow.....
THANKS EVERYONE FOR THEIR HELP, THIS PLACE IS GREAT !!!!