1998 Dodge 12-valve Cummins no start

RenegadeT

no shirt,no shoes,no dice
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Mar 24, 2005
Location
Stokesdale-Greensboro
First off, my truck is an electrical mess. I've been driving without the IOD fuse (I think #10) for years now, that's where I found a battery drain. When it was in, I was able to still run radio, wipers, hvac fan, blinkers, power windows, etc with the key position in LOCK/OFF, no key required.
It's been ok, but over the last year or two, the gremlin started growing. No instrument lights, dim pass. side headlight (only 5V at the bulb socket), interior lights rarely work, trailer brakes only work with manual switch. 2 weeks ago, I had an Autozone battery go "bad"; it was 2.5 yrs old, so replaced under warranty. The other battery was "good", so it's still in the truck.

So yesterday, I was making many local trips, starting/stopping here and there, shutting down/starting up with no problems, until of course it wouldn't start at all. Almost no signs of the battery being connected, kind of like trying to start without the clutch depressed, except headlights and hazard lights wouldn't work. I thought it very strange that the key-in-cylinder buzzer was still working. I disconnected the batteries, measured 12.7v at each battery. All fuses underhood and in dash looked good, except the 40amp fuel heater was burned. Swapped it with another marked trailer lights or something, didn't expect any change, still didn't start (PO had removed the fuel heater).

I zip tied the fuel shutoff solenoid up, pop started the mofo (glad I don't have automatic tranny), and drove it home. Now I'm kind of at a loss where to start diagnosing this.
This truck spent its first 8 years of its life near the beach outside of Boston, MA. To say that rust and corrosion have taken over would be an understatement. PO also has some WVO solenoids wired in the mess somehow. Besides getting these out, where should I start looking?
 
Sounds like a trip to LKQ for an unmolested wiring harness??? Electrical fires while going down the road ain't much fun.
 
Wow, it's been over 3 months, and I haven't done much. Right now, I'm poking around with the meter, and this doesn't make sense to me.

I have one lead on the negative terminal of the primary battery, then the other end on the ring terminal to the underhood PDC. when I disconnect the terminal and probe the bare wire, I get 12.35 volts...makes sense. When in touch the terminal to the stud where it was bolted too, voltage drops to 0.01. FWIW, ignition key is set to RUN.
I don't understand why it drops almost to zero, and I certainly don't know where to go from here.
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I've got a 1st gen 12-valve, 6-years older. Mine has several fuse links coming off the big cable from the + post of the battery. Can't say yours does, but might be a good possibility. I spent a whole day last year tracking down a starting problem. Mine turned out to be ignition switch and 2 relays. Runs like a top now. Good Luck! :)
 
Wow, it's been over 3 months, and I haven't done much. Right now, I'm poking around with the meter, and this doesn't make sense to me.

I have one leaf on the negative terminal of the primary battery, then the other end on the ring terminal to the underhood PDC. when I disconnect the terminal and probe the bare wire, I get 12.35 volts...makes sense. When in touch the terminal to the stud where it was bolted too, voltage drops to 0.01. FWIW, ignition key is set to RUN.
I don't understand why it drops almost to zero, and I certainly don't know where to go from here.
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That's because the cable isn't capable of carrying current. It's called a voltage drop caused by excessive resistance (corrosion in the end, a broken wire, blown fuse link etc) in the wire. I'd make a new cable and test again!

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I tried taking the cover off the steering column to check ignition switch, but it looks like I need a long tamperproof Allen wrench.

Underhood, I guess I need to start looking at all my big cables and measure resistance. With such a big voltage drop, I would've expected the wire to get hot and maybe burn up...maybe a fusible link did somewhere else. Man this sucks.
I do have the FSM on CD somewhere, better dig that up too.
 
Resistance test won't tell you diddly on a big cable, you could have one strand of copper in good shape and show 0 - ohms. No reason to check bigger cables, just verify that the voltage at the battery remains the same when it's connected (make sure the battery isn't dead) and verify the drop isn't in the terminal itself.
I see two or three of those a month with a similar drop across that wire or a battery terminal without evidence of excessive heat.
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I'm really glad that mine only has 4 wires hooked to the motor :D

I have nothing useful to add!
 
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