How are the batteries wired in the diesel trucks? I have the two batteries and someone asked me the other day if I could give them a jump start and I wasn't sure how to hook the cables up to my batteries since there are two of them. Are they wired in series or are they parallel? Does each one run separate components? Thanks in advance.

basstardo

 

Good Question , I had been wondering this myself about my truck...
I am sure someone will have the answer.

 

Jump like you would any other negative ground system. Put the positive jumper clamp on a positive battery post, pick one if you have two batteries. Then put the jumpers negative clamp on a grounded motor bracket or something like that. I don't like to put the ground clamp on the negative battery post. If there has been a over charge and there is hydrogen gas venting off the battery look out if you spark at the battery it can blow up in your face.

 

Gentlemen,

The batteries on our trucks are wired in parallel. When the batteries are in parallel, the voltage remains at 12 volts, but you get lots of amperage to operate the glow plugs and to crank that gem of an engine when starting it.

FYI, batteries in series doubles the voltage, but the current out put remains the same. There is always a trade-off.

Take care.

Steve

 

It's not a good idea to jump start batteries unless you are sure of the battery you are jumping is good.
I jump tried to started a boat with my father in laws 94 f-350 and he had to buy two batteries the next day!
my doughter help a friend once and two day's later I was buying her a battery.
over and out
gseeders

 

Over the years I have probably jump started 25-30 vehicles. I learned a costly lesson 5-6 years back. While driving into a parking lot I was ask if I could jump start a vehicle that had a dead battery. Sure I said. Got out my cables and proceeded to give er a jump. Well their vehicle started and mine died. Wouldn't start again, just cranked it over and over. Had to have it towed. Come to find out that with the computer systems in todays vehicles any type of feed back or fluctuation can burn out computer diodes. This lesson cost me close to $500. Need a jump? I'll be happy to give you a ride, call AAA or even with my new beast I'll give you a tow. Give you a jump? Not a chance. Oh, by the way, those folks I jumped, would'nt even return my phone call much less offer to kick-in a few buck to help on the repairs. That's ok though, all is forgiven, just don't ask me again. Don't have to hit me in the head with a bat lesson learned!

 

I think you'd be safe jump starting someone with a PSD if you disconnected the cables from the passenger side battery and then used that battery for the jumper cables. I sure hate to let that positive clamp ground out on something though.

 

Jumping another vehicle shouldn't be a problem - normally. There are a few things to consider though. First, jump from the main battery - the one on the passenger side that actually connects to everything (the drivers side battery simply parallels this one, but it has a smaller cable). Personally I'd rather jump straight from the battery terminals so long as there's no danger of explosion (meaning my batteries haven't been under a heavy charge). The idea about connecting the negative to a chassis ground is great if you're afraid your batteries have been taking a heavy charge and are currently out gassing, but if that's the case I think I'd just say "no" and let someone else do it - here's why.

The only reason to connect the negative jumper to a chassis ground is to keep a spark from igniting the hydrogen that's emitted from your battery during a heavy charge. If that's the situation then you probably already know it if you've been watching your gauges or having trouble (in which case you're not a good candidate to jump start someone else anyway). If your batteries are low, weak, or your connections aren't good you could be in for real trouble. Let's assume the other guys battery is open, not just a little low (and low enough is as good as an open circuit) and your battery terminal connection isn't the greatest (or your batteries are low or weak). You now connect the negative jumper cable to your chassis ground and the other guy tries to start his vehicle. Initially, it pulls your trucks voltage (wiring harness, not necessarily battery voltage) down as he cranks his vehicle. Once his vehicle starts his alternator sees the demand and puts out full power (as his engine revs). This creates a big surge in voltage which "should" be absorbed by his battery and yours, but that bad battery of his isn't absorbing the charge so the power is heading toward your vehicle instead. Remember that bad connection on your battery terminal? Instead of absorbing that big surge only part of it goes to your battery because of the poor connection - the rest of it is heading right into your trucks wiring harness, elevating the voltage in your truck. Your truck's computer is going to love you for it. If you're lucky the surge suppressors in the computer will handle it for you - but if they can't they'll fry. Will a fuse protect you - probably not. It all depneds upon who dies first. Fuses don't blow as fast as semiconductors so it's pretty likely that by the time the fuse blows your computer has already died. Maybe the whole computer, maybe just the surge suppressors, and if you're really lucky maybe just the fuse. Someone here said they lost the "diodes" (surge suppressors and/or voltage regulators) in their computer doing this, and now you know why.

So what's the safest way to jump someone else? Hook up and let your truck charge their battery. Disconnect BEFORE they try to start. It might take longer but it's a lot safer.

Bob

 

Hmmm, I never considered that surge back through the wiring harness scenario. Good point Bob. Hate to take a chance on a battery explosion, or a diode failure. Guess if I continue to be a good ole boy helping where I can I might get one of those Jump It boxes that Prestone makes. Or, unhook one truck battery and jump off the posts.

 

the way the owner's manual says to do it

use ONLY the Battery on the passenger side.
connect your cables to the battery of the truck, ground first on the other car to chassi, then truck positive and then other vehiciule again, let sit for 2 mins, then start car, do not rev engine .

prevents negative power feedback from blowing battery up or electronics of truck.