If the glow plugs were drawing enough current to draw two good batteries down 4 volts I am pretty sure it would pop the fusible links.

I would suspect a bad cell or a bad battery. It is possible, though maybe not likely, for a battery to show a good charge until a heavy load is placed on it.

 

I'm with David, it sounds like one or both batteries are bad.

12.7 volts is 100% fully charged.

The trick with the "on the bench" testing is that the load they put on them doesn't even come close to what a diesel will require to crank over and actually start.

One of the keys to my thinking is that if you leave the charger on it and then start, it starts right up.

Just for grins, charge the batteries to 100%, turn the headlights on for 10 seconds, turn them off, and then check the battery voltage right at the batteries. Leave it overnight.

Check the voltage again in the morning. If it's not 12.6-12.7, you may have a parasitic drain. If they are still showing near 12.6, try to start it. Then check the voltage again. If they are back down to 8 volts, those batteries are suspect.

 

Another thing I didn't consider last night is potential corrosion in the terminals or grounds. If there is enough corrosion it can allow low amperage through (like the amperage required to test the voltage), but hit it with a high load and it can't get by the corrosion.

 

And said corrosion will get VERY hot under a high load.

 

that is what the "voltage drop" test is all about. measuring the power loss due to degraded connection or cables. eg pos test lead directly on pos battery post, and neg test lead on pos post on starter. set meter on 4-5 volt scale if not automatic, nothing will show.....until someone hits the starter. the number that you get is the amount of voltage the cable cannot carry. lower is better, .005is good if you get into the .1's or higher its real bad.

 

Glow plug is an issue, but not the root

3yrs back my Durango wouldn't start. All the accessories ran fine, multimeter said 12.5-13 volts directly read

Swapped battery out from F-150...it fired right up. Took battery for load testing. Passed with flying colors. Put it into F-150 and truck wouldn't start. Called Interstate and they said it was a bad cell. They tried denying it at first, but I could prove battery was culprit

If the battery was discharging quickly enough to die with just 1 cranking session, you'd have a fire under the hood. Ever get it resolved?

 

actually not always. back in the day i had a chevy 6.2 diesel and the batteries were not bolted down. i hit a bump and everything went black,no lights, no power windows, no power locks. bailed out though the rear sliding window popped the hood and found 1 pos post welded onto the body. i gave the battery a good jar to break it loose and the lights came on dim. starter would not even click so in less than 1 minute with the engine running and the alternator charging it killed TWO batteries and DIDN'T start i fire.

 

Ok, went back to interstate this morning, after I tried to start the truck and it cranked for 6 secs and then died out like normal. After yesterday it start and ran just fine. Was super polite and basically told the dude what everyone has been saying. He tested again and said it's got plenty, but I remember you and your truck from this fall. I'll replace them. Unfortunatly, over the weekend they sold out of the MAGATRONS so I am waiting for the shipment.

I drive the truck to a shop that I have had some work done at before on my 150. NCR Imports in Forest Lake, MN Ken the owner shops at my store and I love keeping small business that do good work going. Knows me by name and we chat here and there about local issues and family etc. I drop the truck and tell him the symptoms, and about getting fresh batteries. He's an interstate dealer and tells me have them drop the warranty batteries here instead of me running around. DONE interstate agrees!

So, here i sit at home hoping for the good news... Ken seems to think my Code is just telling me something is wrong with the GLOW PLUG SYSTEM, maybe not the actual plug. He's going to drop in the new batteries. And get a data stream going on it and see what's what. Hopefully my baby will be back in my hands tomorrow running like the champ I know she is and I'll be on my way to Denver for my show and some snowboarding.

I have no issues with being a DIY type guy for themost part, and really appeciate you guys help! If you are in MN and need a mechanic that in beyond fair, does great work and treats you like you actually knw what's going on go see Ken at NCR. Tell him Don sent ya!

 

I hope that new batteries will fix your problem. I think it will.

One thing I know from past experience is that low voltage can cause all sorts of codes that don't have anything to do with actual problems but were just caused by low voltage.

Once you get the voltage problem fixed, I'm willing to bet that the codes will not return.

 

Let us know how it works for you.

 

IT's back again... Same symtoms, The last time he brought my Alternator in and had the Diodes upped to 180 (I think). Been running great all year until we got cold around here. Now fighting it again. I brought it back to Ken and he took apart the Alt and thought the positive terminal was coming loose so he sodered that back together. I picked up the truck and it was running great showing good voltage etc. Went to start it later that night back to clicking. Ugh, this is killing me. Not being able to trust that my truck will start is brutal.

I think I am in need of some true tracing to the source wiring help.

 

Can you get Interstate to install a couple of new batteries in it to confirm that the batteries are not the problem? I have never gotten more than 2yrs out of the batteries with a powerstroke,