My 92 Dodge-Cummins finally let me down (almost)

JDemaris

Well-known Member
For the first time ever, my truck wouldn't crank over yesterday. That when I was in the middle of nowhere, in the woods, with a full load of maple and oak.

My first thought was, it would be the last time I'd buy a junk NAPA battery. It tried to crank and then it just petered out, just as if that battery was bad. Note the battery is only a year old.

Keep in mind that these 1st generation Dodge-diesels use one big battery like many farm tractors, not duals hooked in parallel.

Luckily, I was parked on a steep mountainside, and I've got a standard trans. Rolled and popped the clutch in 2nd gear and it fired right up.

Truck is now in my shop am I'm still perplexed. I load tested the battery and it's fine. I then load tested battery power at various points. No power when I hook my tester ground to the engine. I also noticed that when I tried to crank the truck, the 10 gauge ground wire started to melt - that connects the battery ground to the body of the truck.

So - the fix ought to be simple, right? Acts like an engine/starter not getting a proper ground connection.

The main 00 sized ground cable runs directly from the battery to the engine block. There it is bolted with a large 13 mm bolt. So, I load tested at the bolt head and it reads fine. Then tested at the engine block and got nothing. And, the bolt is tight. ??? I pulled the bolt out, wire-brushed the block and brass cable end, and still, no-good. That's as far as I got. A simple fix has gotten a little complex.

I'm now wondering if that bolt got so oxidized, the threads are actually insulated? Doesn't seem possilble, but I'll have to figure it out tonight.

I'm thinking of just making up a second cable and running it from battery NEG directly to the starter.

Funny after all these years that this, all of sudden happened.

By the way, just for a test, I stuck some Vise-Grips on a starter-motor bolt. I then ran a jumper cable from the Vise-Grips to the battery NEG post and it fires right up. Seems the 10 gauge chasis ground wire was smoking because the starter was trying to pull high amps through it - since it was starving otherwise.

Anybody else ever have this happen to an old Dodge-Cummins?
 
(reply to post

at 09:18:21 09/06/10)


Id start simple.
Check things like the battery/starter cables for corrossion.

I have had a ground cable stop my truck dead, with no warning, and all it was, was corrossion built up on the connection.

Whatever it is, its simple, and an easy fix.







On a somewhat related note, my father and I are in the market for a 12v Cummins, 2500, with a manual. Just need something to pull a 9,000lb gooseneck with our tractors on it.
 
Shiny up the flat at the bolthole, and put a copper washer under the terminal end. Unless the terminal end is loose on the cable, it should work. Then spray on some rubberized undercoat to keep moisture out when done. Jim
 
Sounds like the ground cable has failed under the insulation . Probably at the crimp.
Try a jumper cable between the battery negative and the engine.
 
Every problem I ever had with a Cummins engine starter was always with the ground cable where it connected to the starter.
 
sounds like ground cable terminal is corroded inside terminal...i had one on my f150 give me fits cause it looked fine...drove a nail in beside cable and it fired rite up...roadside fix.
 
Like some of the other guys have told you. The ground cable is corroded inside of the insulation. It is a very common problem on high amp cables. I get a few each year on diesel tractors. Start by removing the ground cable. Some times you can feel the bad spot because the cable will not be as flexible where it is corroded. Then cut back the insulation a little at a time, starting at each end. You should find it easily. If it is close enough to an end just shorten the cable past the corroded section. Replace the terminal end and tape up the insulation, The insulation on the ground cable is not as critical as the positive cable. If not you will just have to replace the cable. Make sure and use a heavy gage wire car, cables are not heavy enough.
 
If your load test was fine at the bolt head then my bet is both the bolt threads and block area where the it is fastened have enough corrosion to offer a high resistance.
I had that problem once on a 1978 van and I really had to scratch up the block area to get a connection. If that is not it then like the others said the cable is probably bad.
 
Like this one? 120K miles a 96
a21753.jpg
 
Yeah, I just put 1500 miles on it on a trip to Canada fishing. Pulling an 18 ft Alumacraft, walk through, 115 hp motor, boatload of supplies for 8, and averaged 20.1 mpg at a hair under 70 mph. It does not have the 4:10 axle. But pulls 10k up a pretty steep hill in 5th gear. Spent it's entire life in climate controlled shop.
I can put put on my buyers list. Only three guys ahead of you.
Would I trade it for a new one? NOT.

Gordo
 
(quoted from post at 17:18:21 09/06/10) For the first time ever, my truck wouldn't crank over yesterday. That when I was in the middle of nowhere, in the woods, with a full load of maple and oak.

My first thought was, it would be the last time I'd buy a junk NAPA battery. It tried to crank and then it just petered out, just as if that battery was bad. Note the battery is only a year old.

Keep in mind that these 1st generation Dodge-diesels use one big battery like many farm tractors, not duals hooked in parallel.

Luckily, I was parked on a steep mountainside, and I've got a standard trans. Rolled and popped the clutch in 2nd gear and it fired right up.

Truck is now in my shop am I'm still perplexed. I load tested the battery and it's fine. I then load tested battery power at various points. No power when I hook my tester ground to the engine. I also noticed that when I tried to crank the truck, the 10 gauge ground wire started to melt - that connects the battery ground to the body of the truck.

So - the fix ought to be simple, right? Acts like an engine/starter not getting a proper ground connection.

The main 00 sized ground cable runs directly from the battery to the engine block. There it is bolted with a large 13 mm bolt. So, I load tested at the bolt head and it reads fine. Then tested at the engine block and got nothing. And, the bolt is tight. ??? I pulled the bolt out, wire-brushed the block and brass cable end, and still, no-good. That's as far as I got. A simple fix has gotten a little complex.

I'm now wondering if that bolt got so oxidized, the threads are actually insulated? Doesn't seem possilble, but I'll have to figure it out tonight.

I'm thinking of just making up a second cable and running it from battery NEG directly to the starter.

Funny after all these years that this, all of sudden happened.

By the way, just for a test, I stuck some Vise-Grips on a starter-motor bolt. I then ran a jumper cable from the Vise-Grips to the battery NEG post and it fires right up. Seems the 10 gauge chasis ground wire was smoking because the starter was trying to pull high amps through it - since it was starving otherwise.

Anybody else ever have this happen to an old Dodge-Cummins?
The definitive way to pinpoint the problem is with a voltmeter. Put the negative lead of the meter on the negative post of the battery. Then scratch a bright spot on the frame of the starter and attach the positive lead of the meter here. Have someone attempt to crank the engine and you will read the total voltage drop in the ground circuit. Keep moving the negative lead back toward the starter. When the voltage drop goes away, the problem is between the lead and the negative post. For example, if the negative lead is on the engine block and the positive lead is on the starter frame and you don't get a reading, the problem is not corrosion between the starter frame and the block. Put the negative lead on the head of the bolt and if you get a reading the problem is corrosion in the bolt threads. This is unlikely. Stick a needle or pin in the cable and take a reading while cranking. If you get a reading the problem is where the copper is soldered to the connector.
 
Well Sir, after you have tried what they said, and I do not disagree that's for sure, you have two more trouble items in the circuit.
The contacts in the starter solenoid and the relay on the fire wall. Both go bad quite a lot.
Sounds like the relay on the firewall is ok, but I would question those starter solenoid contacts.
I replaced the starter before I got my head out of my backside and started listening to folks.
There is a quarterly magazine called turbo diesel registry. They have tons of information in them.
There is also a vender called Gino's gargage. That is the cheapest place I found to buy the solenoid contacts. I put those in...and never looked back. They are oversize and work great.
Just my 2 cents....
 

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