Need some help about why my truck won't start

Wicked · Jan 22, 2014

OK so here is the background:

As it began to get colder this winter I thought that maybe my original 140k mile starter was on its last leg as my truck had started to take long slow cranks to get it to start up. I still had a warranty on my batteries so I took them to AutoZone and had both Duralast Gold batteries replaced. Truck started better for a week or two but then went back to slow cranks. A month later as the temp has been colder now (roughly 25-35 every day) it would take sometimes 2 times to try and start before finally starting.

Monday morning I went out to start my truck and it did not kick over on the 2nd try and by the 3rd there was no where close to enough juice to kick her over. I came back at lunch and hooked up a Mazda 3 to try and jump it and could just not get enough juice. So I called AAA to come out.

AAA comes out and we begin to try and jump it. We find out that the negative ground on the drivers side to the engine is very loose. Given that we had no tools to tighten it up we pulled it tight to try and get a ground and start it. Hooked up 2 jumper boxes and his little truck. Had 11 volts or so and it was cranking fast and great but just never started. It got late and we decided to give up but right before he left I had him test the batteries. I manually held the ground for a good connection and his test said I was getting a total of 770 CCA... Any thoughts on what it could be? Am I in some sort of safe mode? Is it sensing a poor ground? Any and all help would much appreciated before I have to pay to get it towed.

Stroked383 · Jan 22, 2014

With a total of 770cca sounds like you have a bad battery connection and only using one battery to try to start it while below freezing temps. Which as you found out isn't going to happen. I'd start with cleaning all battery cable ends (just because I they don't have a bunch of corrosion on them that you can see doesn't mean that they are clean and making a good connection) and make sure they are tight. If that doesn't help and it still cranks slow I'd check the negative connections at the block.

PSD POWER007 · Jan 22, 2014

I also bought a large gauge ground cable for each battery and ran another set of grounds to the frame.

mandkole · Jan 22, 2014

starter and batteries are both fresh? You said the starter had 140K on it, but did not note if it was replaced.

The starting circuit needs good terminal connections, grounds, relay, starter, batteries, glow plugs, GP relay... Its a basic system so checking everything for clean connections is fairly easy. Another thing to think about is any draw on the system from other components while shut off. If you do not run it everyday, the batts will eventually draw down. My truck only runs every other week or so, and its on a trickle charger all the time. I dont have patience for battery/starting issues...

Fly By Night · Jan 22, 2014

Id check all my connections and see where that gets you, 770 cca is a little less then what ONE battery should produce in one of these trucks. Did you disconnect the battery's to isolate them while testing them? If its not starting while being jumped Im going to guess that its a wiring issue or your starter is toast.

Wicked · Jan 22, 2014

Yea sorry... batteries are fresh... starter is not (140k miles). I am going to get my tools and check everything out tonight and see if it will go.

I assume that when AAA was out the computer/something was sensing a poor ground so it would not let it turn over???? When we had it hooked up to everything it was cranking the best I had ever heard it and would not kick over. Noticed some black smoke coming out the stack after several 8-10 second cranks.

Wicked · Jan 23, 2014

Ok so I tightened all the grounds and took the batteries to AutoZone (Duralast Gold) and had them checked and charged. Turns out one of them was good, the other bad. I know your supposed to replace both at the same time but they are only 3 months old.... So the good one was charged up and I put it and a new one in the truck. Everything works fine now.

My question is: Could a loose ground on one of the batteries kill it?

When he first checked them one was at 50% and the other 26%. I did not mark the one that did not have a good ground (which I regret). One took a charge and tested good and the other did not hold the charge and obviously tested bad.

Thoughts? Am I in the clear?