Well I've got one new battery and one good battery. I can charge them up all night to full, and i'll still have trouble getting the rig to start in like 45 degree weather. This is after the glow plugs do their thing, and the glow plugs are all new and the controller is working fine.

It's just cranking slow. Once I've been cranking it for a minute or so then one of two things will happen: the batteries will run low and it will start cranking slower or it will just start cranking faster and once it does it will fire right up.

The cables on there are used factory cables. Cleaned up the terminals well.

Thanks
-Matt

 

Keep in mind that even though the battery terminals are clean, corrosion can find its way up into the insulation and cause problems that you may not be able to see.

May be cable related or a dragging starter. Do you have a multimeter or an amp meter to test for voltage drop at large starter battery terminal and starter draw while cranking?

Jason

 

I can test the voltage drop but the current limit on my multimeter is not even close to 1500amps or whatever

 

I had this problem. It was the starter. $130

Starter and Batteries
The first thing you should check for on a no- or hard-start concern is the batteries. Clean the terminals and check each battery individually (one negitive cable disconnected). They both should pass a 15 second load test of half the rated cold cranking amps (voltage drop no lower than 9.6 volts). Starter draw should be no higher than 500 amps with both batteries connected and engine RMP should be no lower than 200 RPM.
If the cranking speed is too low, the engine won't produce enough compression to ignite the fuel.

 

Look at the passenger side battery cable close to the battery clamp.

Does the insulation look discolored like it has been hot?
Is it hard and brittle?

If so, you have internal cable or clamp corrosion.
All power goes through the passenger side positive clamp.
That is where the alternator, both batteries and the starter wires all come together.

 

Fluid Film protects battery terminals for at least 12 months. A little goes a long way...

 

Also I know in theory I know it should work, but I have never had any luck replacing one battery, even in my trucks with 4 batteries I bite the bullet and replace them all. Which sucks because I wind up with three good matched batteries.

 

Well since this truck has been running my bank account dry and i just snapped my front axle stub shaft, a second battery will have to wait. I really don't think that's the problem here. Even at half of it's rated life the engine should be able to crank faster than it is.

There is some corrosion at the positive passenger terminal but it appears to me to still be a sound connection. I measure 13.4V at idle across the passenger battery so i think it's charging just fine.

If I remove the starter and take it in to be tested at NAPA will they be able to tell if it's bad because of drag? Technically it still works but it seems like it's weak.

Thanks
-Matt

 

Any visable corrosion is hurting you. There are several ways to help The one I use is to soak it in baking soda and water, several times if neccessapy to get the shiny copper back, another I have used is coke to prolong the life a little.

 

 

OK OK what is so funny, it will get all the green stuff out and make the copper shine, really really.

 

its true Rodney.Coke is great to eat rust and corrosion.

lemonshindig,
if you can see the corrosion,then it's much worse than you think.if you to slice down the cable,you would see green flaky corrosion.this REALLY hurts these trucks big time.
since $ is tight right now,slice it right open (it needs to be replaced anyway at some point) and pour the Coke right to it.
next,wrap it back up with tape.this will keep ya going for a few weeks,or heck probably a month or more lol.but replace it as soon as you can.

also,don't forget to clean up the starter wire connection down at the starter,and the ground at the block/take a piece of sand paper,and make the contact points real,real shiny.then coat with a good healthy dose of grease.
this doesn't cost anything,and can make a world of difference.
you probably have a combo of problems now.bad cables and a worn out starter.sorry for the bad news.this will set ya back a few hundred total now.
have the starter tested first tho.
remember 20 second MAX cranking a starter.and let it set 2 minutes MINIMUM between cranks.
once you fix these things,test your GP's.
good luck.looks like you'll be saving a little green for some maintenance,but these tips will help ya keep going for a bit.
don't forget,replace a burnt out GP with a motorcraft only,and dont feel bad about plugging the heater in a couple hrs before the first start of the day to help your starter keep going for ya.

 

I guess you have never used coke to clean the bugs off the windshield or to soften the bead on tire before changing it either. lol There are better uses for coke than drinking it. lol

 

The glow plugs are all new motorcraft and they're working wonderfully.

 

Going by your first post when you said that it will sometimes start spinning faster leads me to belive it is a cable or connection problem that heats up and mahes a better connection. It would be rare in my goofy way of thinking for a dragging starter to speed up after you have used some of the available cranking amps.