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Dead batterys

133 Views 4 Replies 5 Participants Last post by  97F250HDXLT
Is there a better way to go about jumping my truck, I originally had just a nother truck trying to jump my truck but I never got very far, I used a battery charger too on the other battery and it’s charging more but I feel like I’m doing something wrong, can I have some pointers or ideas (have a truck and a battery charger tryna jump my truck)
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You need to let the batteries charge for a while with the jumping vehicle attached and running.

On initial start-up you can need 400-600 amps + between the glow plugs and the starter.
Jump on the truck's passenger side batter too. Cheers!
agreed. jumper cables should be on the passenger battery, and let it charge off the other vehicle for at least 5 minutes before trying to start.
if you can leave the battery charger on for at least 12hours that will help put some decent juice in the batteries, unless one is internally shorted
If a lead-acid battery is really "dead" (~0V with a digital multimeter), then it may never work well enough to crank a diesel. Cranking batteries do not tolerate deep cycles well. The SLOWER (lower Amps) that you recharge, the better it is for the battery, but (of course) the longer it takes. The charging current must be higher than the battery's internal discharge current, which means that a trickle charge may not work at all - I'd try to start off around 5~15A for an hour or 3, and then see how low (~0.5A) you can go while still seeing the voltage creep up by the hour. If voltage creeps down after an hour, it's not enough current to charge, and the battery may be shot.

Obviously, it's easier to charge the batteries in parallel like they're normally connected in the truck, but they can interfere with each other's charging. So if you have the time & 2 chargers, it's better to pull the negative cable off one, and connect a 2nd charger directly to that battery, so they'll charge independently.

While you're doing all that, take a CLOSE look at the terminals (and post pictures here). If they're dirty, loose, or corroded, the batteries will never charge properly, and the truck won't run right. Pull them off & clean up every mating surface so you have shiny metal touching everywhere. This page explains in more detail:

1983 Ford Bronco Solder-On Battery Terminals pictures, videos, and sounds |

This page shows what I found on my '97 7.3L, and the links below the pics show how I fixed it:

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