How do I check battery cables?

[DennisG01]

Is there a proven method for checking battery cables? Everything looks OK on the outside, but I was wondering how to go about checking them out - would a resistance check from one end to the other be sufficient?

[Dvldog8793]

Howdy
Any kind of resistance check is going to read good unless something is REALLY bad. The best way to check them is to make sure that they are stil flexible and that the insulation has not been compromised. If the ends are not sealed properly and corrsion has been present it will work its way into the cable and cause problems that you will never see. In my opinion, The cables from the factory are undersized and the side post ends are inferrior to the older top post type. Top post are MUCH easier to maintain, normally have a larger surface area, and can easily be inspected without disassembly. The bad point about converting to new cables and ends is that in order to do it properly it can get expensive and time consuming. I doubled the size of all my cables and had over $100 invested by the time I was done(about 5hrs). I know it paid off because when it comes to electricity bigger wires are better. When I worked for Motorola building squadcars one of the first things that we would do would be remove the side post terminal if possible(Fords had top post, Chevy has side post) This not only gave a better connection but also more room to add our aux power wires.
Hope this helps....
Conley

[Robyn]

Without cutting the red plastic off the ends to expose the crimp area its really impossible to tell much.

If they are a few years old (5 or more) toss them and get a new set in there.
The grounds can fail badly at the engine end and not look bad at all.

[Mikeandwendy74]

Yes you can absolutely check the cables with a meter. First thing would be to check the insulation as already stated give it a good bend. Zero cracks and a resistance check within specifications will give a good cable. Most battery cables are 4 awg(american wire guage) and around 35 inches so....4 awg 3 feet long with resistance at .000292 ohms per foot should read out on a meter at approximately 0.000876 ohms. Hope this helps :)

[winemaker]

I don't know anything about testing them, but I can say that I removed the stock fastener in favor of the bolt method described somewhere in the DP. Before I did it, I had to tighten the pos terminal a few times. I decided I'd had enough of that and did the fix. No problems since.

[JohnC]

Most Ohm meters aren't that sensitive. An easier way to get a handle on it is to measure the voltage drop on the cable when it's under a load. The bigger the load the better. Starter is great but not convenient, glow plugs is good. A battery load tester is good. Headlights are fair....

[d350diesel]

The best way to test battery cables is voltage drop. Put the positive lead of a voltmeter on the positive battery terminal, and the negative terminal down on the starter. Crank the engine and observe the meter. More than 0.2 volts is bad, means you have a dirty connection or bad cable. The ground cable is checked the same way, except the positive lead goes on the block and the negative lead goes to the negative battery terminal. If cleaning the terminals does not fix the voltage drop, replace the cable.

[DennisG01]

Thanks, everyone. I'll do the voltage drop method as my meter isn't a very good one. Thanks for the numbers, though, Mike - I didn't realize the difference between a good one and bad one was so close. The truck is starting fine, it's just the first second or two is a little slow. But then it picks right up. Maybe that's just because it's been pretty cold, though (1* this morning).

What's the most convenient method to enable the starter to turn, but not have the engine start? Take off the 2 main glow plug wires?

Thanks!

[DmaxMaverick]

Thanks, everyone. I'll do the voltage drop method as my meter isn't a very good one. Thanks for the numbers, though, Mike - I didn't realize the difference between a good one and bad one was so close. The truck is starting fine, it's just the first second or two is a little slow. But then it picks right up. Maybe that's just because it's been pretty cold, though (1* this morning).

What's the most convenient method to enable the starter to turn, but not have the engine start? Take off the 2 main glow plug wires?

Thanks!

Disconnect the FSS (fuel shutoff solenoid) connector. It's the wire connection toward the front/top of the IP. That will prevent the pump from delivering fuel.

Disconnecting the GP circuit may prevent starting, but fuel will still pump into the cylinders. Could make for an exciting experience when you do eventually start.

[rustyk]

A quick check is to turn on the headlights and crank it. Headlights that dim considerably indicate either bad connections at the battery or ground, or that the cables are bad. This won't replace a thorough check, but it will indicate that one needs to be done.

[DennisG01]

Disconnect the FSS (fuel shutoff solenoid) connector. It's the wire connection toward the front/top of the IP. That will prevent the pump from delivering fuel.

Disconnecting the GP circuit may prevent starting, but fuel will still pump into the cylinders. Could make for an exciting experience when you do eventually start.

Is the FSS connector the one that is directly underneath the upper intake plenum?

After I wrote that question about removing the GP wires, I started wondering about exactly what you just said. What sort of things could happen? Anything damaging? Let's assume (between checking all of the cables) I use a total of about 30 seconds of cranking time.


Rusty: How much is "considerable"? Currently they do dim somewhat - slightly more than the difference between having the DRL's on compared to physically turning the lights on.

[DmaxMaverick]

Is the FSS connector the one that is directly underneath the upper intake plenum?

After I wrote that question about removing the GP wires, I started wondering about exactly what you just said. What sort of things could happen? Anything damaging? Let's assume (between checking all of the cables) I use a total of about 30 seconds of cranking time.


Rusty: How much is "considerable"? Currently they do dim somewhat - slightly more than the difference between having the DRL's on compared to physically turning the lights on.

Well, if you disconnect the glow plugs on a cold engine, and crank away, it shouldn't start, but it is still pumping fuel into the cylinders. After, if you reconnect the plugs and try to start, there could be enough fuel in the cylinders to cause detonation. That's when the fuel ignites before the piston reaches TDC. If it is enough before TDC, and there is enough fuel, it could cause some serious engine damage, like bent rods. The same result can happen from hydrolock, if you get more fuel in the cylinder than there is space for it. Another possibility is post-combustion detonation. That's when enough fuel is in the exaust system it will detonate when the heat is increased after the engine starts. These conditions are rare, but can and do happen. Keep in mind, this is a Diesel engine, and is designed to combust fuel with compression heat. If you get enough fuel into the cylinder, the relative compression ratio can be increased enough to combust the fuel w/o the aid of glow plugs. Also, excess fuel pumped into the cylinders that doesn't burn or get pumped through the exhaust port will wash past the rings and end up in the crankcase, removing lubrication from the cylinder walls in the process.

That said, 30 seconds of cranking won't likely cause any issues. You may experience a higher than normal RPM surge when you finally start. The engine will burn all the fuel you pump into it, and sometimes all at once, so keep that in mind.

The FSS is located on top of the IP, at the front (verticle cylinder with harness out the top). I'm not sure where your connector is, but it could be under. The harness length is dependent on the part #, which varies. Just follow the wires to the connector. Disconnecting the FSS will prevent the fuel delivery event by blocking fuel flow entering the pump.