Wont start keeps killing batteries

[07_powerstroke]

Last winter my alternator took a dump so i bought on from federated auto parts. And new Napa batteries. If i let the truck set for a couple days or started and stopped the truck alot it wouldn't start this has been going on for almost a year... two weeks ago I traded my old batteries for better ones at Napa and the truck started yesterday when out this morning won't turn over also I noticed my power window goes up very slow. I have my alternator and both batteries down to the local napw to get tested any ideas? When I tested the batteries after boosting the truck and than shouting it down it said 11.8 volts and the alternator said 11.2 for a couple mins of the truck warming up than it said 14.+ after the truck ran for a couple mins. Any ideas loose connection or what?

 

[Shootingstar]

Ck it for a draw! Disconnect both batts. Then place a test light in between the neg post and neg cable. With the key off is should just barely glow do to the radio memory. If its bright then you have a draw. Pull one fuse at a time to locate the circuit the draw is in.

 

[07_powerstroke]

Ck it for a draw! Disconnect both batts. Then place a test light in between the neg post and neg cable. With the key off is should just barely glow do to the radio memory. If its bright then you have a draw. Pull one fuse at a time to locate the circuit the draw is in.

I don't really understand I am not very good with electronic stuff! So I will leave the positive wires disconnected the whole time?

 

[07_powerstroke]

Is it normal to have the battery light to be on koeo before I start the truck?

 

[wetnsloppy4x]

I don't really understand I am not very good with electronic stuff! So I will leave the positive wires disconnected the whole time?

Not to speak out of turn here, but just the negative side.

Is it normal to have the battery light to be on koeo before I start the truck?

Yup.

Like Shootingstar said, you've got a draw somewhere.

 

[07_powerstroke]

Not to speak out of turn here, but just the negative side.


Yup.

Like Shootingstar said, you've got a draw somewhere.

Ok wonderful I was hoping it was a bad battery or something! I have a multi meter would that work or would it be easier with a light?

 

[Shootingstar]

I don't really understand I am not very good with electronic stuff! So I will leave the positive wires disconnected the whole time?

Leave the pos connected. You are putting the test light inline of the neg cable so you can see the current being drawn.
Make sure you have the key off and all the dome lights off too.
It's best to have a second so one person can stay in the truck an pull the fuses. Don't forget many super duties have two fuse boxes.

 

[Shootingstar]

You need a light. It's much simpler!

 

[07_powerstroke]

Ok so it won't matter what battery I put the light on right? And when I pull the fuse that is causing the problem the light will get brighter or go out? The fuse box under the dash and one under the hood right?

 

[Shootingstar]

I'd ck both batts see which side you get a brighter light on then work from there. When you find the fuse the light will go out
If ya need batts. I've always had good luck with napa or interstate.

 

[Shootingstar]

Oh yea! yes two boxes one in cab and one under the hood.

 

[Big Angry Hillbilly]

Typically on most Ford vehicles you'll need to wait 40 minutes after attaching the test light for all the modules in the vehicle to go to sleep.

One thing to try as a fluke, after the truck sits for a few hours, put your hand on the GPCM, see if its hot. I've seen them kill batteries, but its usually quicker than a couple days.

Good luck, finding this type of problem sucks sometimes!

 

[Big Angry Hillbilly]

Oh yeah. And you asked about the couple minute delay before charging too:

There's a two minute delay before alternator goes to full output. The glow plugs are still on during this time (even though the light isn't) depending on ambient temperature. So the alternator delay is just the max time the plugs will be on.

HTH.

 

[07_powerstroke]

Thanks for all the help guys! I haven't got any news back on how my alternator and batteries tested out. It is -5* here so i don't wana work on it today anyway. Do you think the alternator I bought is the problem it is a 70$ one from federated auto parts. Napa said they can get me a 135 amp one for 225$.

 

[07_powerstroke]

Well I guess the alternator tested bad. I have a Napa 130 amp one on the way with a life time warranty I really hope this is the problem! Its been a on going inconsistint problem for a year now...

 

[wetnsloppy4x]

I'd still make sure you don't have a draw. Starting a truck on nearly dead (jump started) batteries can kill an alternator from the massive charging the alt. is doing to try and catch the batteries up. The newer generation of alternators are much more sensitive to this.

 

[07_powerstroke]

I'd still make sure you don't have a draw. Starting a truck on nearly dead (jump started) batteries can kill an alternator from the massive charging the alt. is doing to try and catch the batteries up. The newer generation of alternators are much more sensitive to this.

I deff still plan on doing the draw check! He said when he tested the alternator and it jumped all around would that make sense why it is inconsistint?

 

[07_powerstroke]

Well I got the alternator and the batteries in along with a fresh oil change with some rev x and the truck seem to run alot smoother! If i get a voltage reading today on the batteries and than check them in a couple days should I see any drop at all? Also how long does it take for rev x to fully start working?