1999 Dodge RAM 3500 5.9L - Won't Start After Cutting Off?

**m67cummins** · 02-08-2023

Hey everyone, my 99 Dodge RAM 3500 5.9L will not start after cutting off.

I just replaced both batteries and got a brand new alternator(not a remanned); it is bone stock, is a 5-speed manual, has 98,000 miles on it, and is my tow rig.

Overall in excellent shape; any ideas of where I should look next?

The truck does not click when trying to start will try to spin over but drains the batteries.

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**AK Bob** · 02-08-2023

Are you saying it cranks but won’t start?

Do you have any trouble codes?

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**m67cummins** · 02-09-2023

It will start with jumper cables hooked up and runs fine after that.

When I start it again without jumper cables, it will crank but not start; it just drains the batteries and no trouble codes that I've seen.

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**AK Bob** · 02-09-2023

Originally Posted by m67cummins

It will start with jumper cables hooked up and runs fine after that.

When I start it again without jumper cables, it will crank but not start; it just drains the batteries and no trouble codes that I've seen.

It sounds like the batteries are weak.

I would have them load tested.

If your truck starts and runs when jump started, it should start with good, fully charged batteries.

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**C-MAN** · 02-09-2023

Which battery are you jump starting the truck off of?

The hooking up of the cables and it starting possibly tell me there is a cable on a positive lug from which you are jumping that is loose or corroded and only seeing power with the jumpers connected/clamped over them.

The alternator charges the passenger side battery and the driver side battery is in charge of all of the electronics of the truck.

It could be a number of things but I would check and clean all of your battery cables on the driver side really well even if they don't look like they need it.

Make em shine with some emery cloth or a scotch brite spin disk.

Especially the cable that runs to the passenger battery and the cable that goes to the fuse box on driver inner fender (clean at the fuse box and check for corrosion where it is molded into the factory lug).

I've also seen plenty of alternators that have been bad right out of the box for 2nd Gen trucks that have bad or shorted diodes and cause such excessive a/c ripple that will mess with the PCM enough to cause a no start condition as well.

If it were me I'd first try jumping the truck from the other battery and see if it still starts to make sure you're jumping power and not just running off of one battery and go from there.

If you are still having problems I would suggest pulling the alternator and have them swap you for another new one because most parts houses dont even know how to test diodes and their machines most of the time will always show a false positive.

I hope this helps.

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**C-MAN** · 02-09-2023

Also, crawl under your truck and check your central starter lug and see if it is loose; they corrode and or burn out over time from so many starts and sit in there almost unconnected and will always slow crank as if the batteries are weak even with new batteries.

Still, the juice from jumper cables might cause it to cross enough direct power to let it start.

Ask me how I know, LOL.

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**m67cummins** · 02-10-2023

Originally Posted by C-MAN

Also, crawl under your truck and check your central starter lug and see if it is loose; they corrode and or burn out over time from so many starts and sit in there almost unconnected and will always slow crank as if the batteries are weak even with new batteries.

Still, the juice from jumper cables might cause it to cross enough direct power to let it start.

Ask me how I know, LOL.

I am going to be doing some more troubleshooting today.

I will check it out

Thanks!

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