OK Here's the deal...<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

This may sound like a strange question, but can "bad" glow plugs cause my truck to see the batteries instantly go straight to ground when I turn the ignition?<o></o>

I'm at a loss here. I have brand new batteries but I only get about 20 seconds of crank time before they are "dead.” I have done everything I can to rule out the batteries. But nothing short of starting it with jumper cables seems to work.<o></o>

I am not a diesel mechanic, in fact this is my first diesel, and I am learning as I go...<o></o>

Thanks<o></o>
<?xml:namespace prefix = st1 ns = "urn:schemas:contacts" /><st1:GivenName w:st="on">Patrick</st1:GivenName><o></o>
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Sounds like a dead short is killing things faster than normal. Could be a short in battery or starter cables? When you are jumping it, it's with a running vehicle? What are voltage before starting, as you start it, after you start it? Ussually if a glow plug or a GP relay goes, it goes dead and no longer consumes power. So I am thinking something else. Any codes?

 

Check the starter cable to make sure it isn't grounding out. What ever it is should have a VERY burnt spot in the insulation where it's shorting out. Suprised you haven't noticed smoke, smelt something burning or had other more dangerous issues if they're going dead that quick.

 

I know the batteries are new, but have you had them load tested? I have seen a couple of batteries whose voltage checked out, but instantly went to zero when a load was put on them.

 

Yes that was the first thing I did. They both registered near the top of the "normal" range. Dummy me I didn't write down the numbers for later reference.

 

I've only been able to look at part of the electrical circuit...good thing is I haven't smelled any "electrical burning" smells.


With the longer daylight hours and the weekend maybe I can take the dash out and look in there too.

For now the truck sits in the drive mocking me and earning it's "Monster Truck" nickname for all the wrong reasons!

 

This is good, sort of. It would be nice to smell something if it was shorting out...that way at least you could find the issue if/where it's grounding out. Dumb question...what condition are your battery terminals in? All four post need to be checked....just saying. How about the alternator...making any strange sounds if/when the truck is running? It wouldn't hurt to check the ground straps that ground everything; I forget how many there are...but there are several. Pretty sure one is under the A-pillar for the body; one is near the starter for the engine. Both batteries ground to the frame as well.I have my doubts it's in the dash, but hey...it doesn't hurt to check there. But there's nothing inside the cabin (OEM spec) that would draw that much power that fast.

 

The first thing I did was tighten the battery cables...last time I had someone else work on it I got it back with all 4 terminals loose...they are all tight now. The alternator is brand new.

I think I'll take a look at the ground straps...thanks for the idea...

 

If you're only getting 20 seconds of crank time before the batteries are dead, then they were either dead to begin with, or they aren't dead, there is some other problem preventing cranking.

Draining 2 750CCA (or higher) batteries in 20 seconds would most likely cause a fire or explosion. I just don't see it happening. At the very least, the lead post would melt from the heat.

So. You really need to make sure they are getting and keeping a full charge. Just because they are new and even load tested doesn't mean they are. What are the voltages on the batteries when they sit, just after you turn the key on, while cranking, just after starting, and after the engine has been running a bit.

After they go "dead", what are the voltages on them and what does it take to recharge them?

Have you inspected all of the cables from the batteries down to the starter, and all of the grounds, to make sure there is no corrosion or loose terminals?

 

hows your starter its self? when jumping it off does it sound, spin normal? have seen plenty of them draw to much current without a burninig smell. also they make an inductive current gauge that you place on the wire to check the draw from the starter.

 

It's not the batteries themselves...not only have I checked them but I also brought it to my mechanic who indicated the same.

I have not checked all of the cabling yet. The only thing I checked were the battery terminals. I tightened them. I will be checking as much of the wiring as I can today.

 

I thought about that...it's a bit more work than looking at the cables and wiring...but it's next on my list of suspects...

 

I know it's been a long time since I first posted this question, but I finally got everything worked out.

It's a long frustrating story so I'll just share the "Cliff Notes" version...

As I stated before the batteries died very quickly. So after I check and had a dealer check the batteries and each time they passed the testing, I ws TOTALLY convinced that I had other issues than the batteries.

I looked at or tested every electrical part on the engine I couild think of and found nothing wrong. I even rechecked the FICM to make sure that the new unit was not defective already.

The only problem I found had NOTHING to do with the electrical system...I had a loose clamp on the "Y" pipe (lol..taht took care of the power issues I had at RPM when towing...and I was starting to think I had a turbo issue).

So after trying to keep a charger on it and stil getting stranded, I went back and rechecked the batteries...guess what?...

It WAS THE BATTERIES

The problem kept getting worse because the batteries kept getting worse...I (and the mechanic) should have realized that since they were first checking at the low side of normal was an indication that there could be an issue wtih them. Oh well, its up and running now.

Oh yeah BTW...Come to find out apparently Interstate has had issues with batteries in diesel trucks before and they have even brought a new diesel specific battery to market, but yet they wouldn't replace mine wiht the new diesel specific batteries....