I have been getting slow starts last 2 weeks. I tested batteys today 12.4 both when not running. Alt test at 14.5 running and load test good as well. my only thought would be the starter moter is going south. Its only 2.5 yrs old and it was a international. Just a good guess unless ther is a way to test the started as well. First crank on truck seems slow like battery going, after it starts and runs it seems fine. any thoughts? thanks Jeff

 

I would double check the starter mounting bolts and wire connections first.
The starter may not be grounded well enough. 3 years on a starter isn't much.

 

I just went through this last winter, I thought for sure starter was finally going bad but I had the batteries load tested anyway & found one batt was pretty weak & the other wasn't a whole lot better even though they read 12.5 v. Two new batteries & starter spins real good again.

 

Charge them puppies up, at least before condemning the starter. 12.4 is low - somewhere between 50% and 65% state of charge @80°F for a maintenance free battery.

http://jgdarden.com/batteryfaq/carfaq4.htm#interpret

 

How old are your batteries? I've had batteries test good but when given a load they showed that they were very tired. Since they're easier to test than the starter, have them load tested first if they're good then take a look at the starter.

 

Our starter started the same thing Friday. We had to go to Orlando Saturday so we load tested batteries, and checked grounds. All ok, so we got a new starter, our auto electric guy leaves after lunch on Friday's for the weekend. He did call though and will rebuild old one FREE. The new NAPA one worked flawlessly. So now we will have a backup.

 

My starter is cranking slowly as well. When the truck was with SkySkiJason to have the clutch replaced he recommended a high torque version and he would install it at no charge. I did not have the funds at the time, and have since found a reputable shop that will rebuild the starter.

I like the ones that CNC Fabrication sells and Corey (owner) is a great person to deal with, but do not like that they are nearly twice the size and don't fit in the space very well.

 

I second that. Battery should be 12.6 or even 12.7. However, I have trouble with my batteries discharging in a week or two to 12.4 or even 12.3 so I keep a trickle (smart) charger on them which keeps them at 13.2. I spent a lot of time trying to figure out why the batteries discharge and never found it. I even disconnected the radio. No change. I have an 05 expedition that does the same thing. 02 Saturn, no problem. Maybe it's just Fords? I would check how long it takes to get to 12.4 after a full good charge. If it's a matter of hours, batteries are certainly suspect.

 

12.80 @ 80°F

Specs change, battery chemistry has improved or modified a little bit anyway over the years. Standard conventional lead-acid batteries (with the filler caps) show fully charged at 12.65 volts. Sealed maintenance free are different, because of the alloys used in the plate material.

Now a tenth of a volt doesn't sound like much, but as a % of battery charge it's quite a lot. Battery state of charge can only be measured accurately after the surface charge has been removed. That means it sets overnight for several hours. Or, turn the headlights on (engine off) for five to ten minutes. Then wait at least ten minutes before measuring. There's a conversion chart at the link provided, keep in mind battery state of charge and charging voltages are temperature dependent.

Good battery maintenance and attention to the grounds cables and connections will pay dividends in terms of good performance and maximum service life.

 

Are you testing voltage with the truck off, or while cranking? Battery voltage dropping too low while cranking, bad positive or negative connections, or a worn out starter are all possibilities.

You can use jumper cables or wiring to bypass cable issues and to boost the existing batteries to help rule them out as well (cables hooked up differently for each test)

If the International starter was a reman, then it's possible it's time is already up.

 

In sure people will tell you how this is bad for a battery, etc., but if your basher are almost toast, why not try it. When my batteries were doing the same thing (not holding charge very long) , I took 1 quart of distilled water and added 10 tablespoons of Epsom salt (like what you put in your bath for sore muscles). I added that to the cells, and charged the batteries. I got 4 more years of off them before replacement. The truth is I was ready to replace them when someone told me this, so I figured it would cost me nothing.

 

A few notes about the Epsom salt reconditioning :

Epsom salt is magnesium sulfate, and when you add it, it significantly increases pH. It is also the active ingredient in the more expensive reconditioners.

When you mix the Epsom salt with water, heat it up first to make it dissolve easier.

After you do this, report your results here. People look at me like I'm stupid, similar to the look I have my wife's dad.

 

You got "another" 4 years, or a total of 4 years from the batteries. Also, a quart is a lot of liquid, way more then I could add to my batteries without overflowing. How did you manage that?

 

The batteries were 2 years old, and I ended up having them almost 6 years total. The first sign of weekness I replaced them. Also, I didn't add a quart. I mixed 10 tablespoons to a quart and added what was needed.

 

Very interesting. I certainly won't be trying it with a good battery though.