Green Mechanic Question;

I have a 1964 F100, 223 Inline six, and I replace the battery cables, negative and positive with four gauge. Should all the cables be two gauge?The original battery cables I replaced also look like four gauge.
After the negative and positive battery cables replaced, I would occasionally get a click, and lose power altogether. When I would receipt the negative cable can go either way. I would either get another click, or it would turn over.
And I read something about a two gauge strap?

Should all the cables be switched over to two gauge? I’ve had the truck for years, and it was running fine… Of course until I fixed it. Any links or info or appreciated.

Thanks,
rtcapo

 

Aahhh, the old "it worked until I fixed it" scenario, been there more than once myself.

If your battery cable length is not significantly longer than the originals then the original cable size should be fine. I write that, because amperage is lost over distance and if you have increased the length significantly, then that might not be carrying the load, thus the clicking noise. Furthermore, it is worth noting that not all materials will carry voltage or amperage the same, copper vs aluminium might also play a role.

Also, you might check the new cables for resistance, they should pretty much have none, but if one of the new cables has corrosion within the insulation, or the connector was not crimped correctly, that too could equate to a problem starting.

Also, it is worth noting, that if where the new cable is bolted to the chassis, and or motor, is not clean, it only takes a little bit of patina (corrosion) to cause power loss. I shared in another thread, that I was having trouble with my Fiat Ducato transport van. It was throwing codes, that the start stop function was not available, (something that rarely if ever worked since new) and in looking further the system implied electrical parts failure. Long story short, after much frustration and throwing some significant, but logical parts at the problem, it turned out that unfastening, and cleaning up all the ground points, solved the problem. In fact, now the start stop function works smoothly all the time.

Lastly, you might check to see if the alternator is charging correctly, that starter solenoid is functioning, and verify if the battery is not adding to the problem, along with all those connections as well.

Hope that helps, and iplease keep us posted as to what you find out.

 

Amperage doesn't decrease over distance - ever. If a starter is pulling 200 amps of current the battery will be delivering 200 amps and the cables will see 200 amps. The cable doesn't determine amperage, but the load draw does determine the amperage. Voltage drops over distance but if resistance stays the same in a given circuit and voltage drops then ohms law says that current (amperage) must increase. That's what causes wires to heat up and eventually start smoking.

 

Well I stand corrected, thank you for clarifying that.

 

The old garden hose analogy of how electricity behaves is applicable to a pure resistive circuit, but the analogy falls on its face when you introduce a real load in the circuit like a motor, starter, solenoid, winch or anything with back-EMF. When voltage drops a resistor draws less current whereas an electromechanical device like a motor draws more current. When the motor slows down back-EMF collapses which causes the effective resistance to drop and current to rise.

 

Personally, bigger is better when it comes to battery cables I think. I have them made at a farm tractor dealer when I need new ones, custom length

 

I agree with the larger battery cables. The originals were 4 gauge if not 6 gauge and many replacements use 4 gauge. Generally, 2 gauge is good for light duty trucks. Larger engines and diesels often run 1 gauge or thicker.

New cables could possibly have an anti-corrosive coating like shipping wax or anti-oxidation film that might obstruct the best of contacts. Sometimes a good wipe of acetone or lacquer thinner helps. The click you hear is likely the solenoid slug moving but there not then being enough amperage to turn the starter. Matt also mentions oxidation/patina. Even with brand new batteries and brand new cables - especially the clamp ends I use a battery terminal brush to make everything look like shiny metal with a bit of a tooth to the surface before I attach the clamps and tighten them down. Make sure the clamps tighten down well. I've seen new clamps that are a bit too large of internal diameter to snug down 100%. I remove the clamp bolt and file the gap to widen it until the tightening of the bolt gives a good snug fit where I cannot turn the clamp by hand on the terminal.

Performance Tool Battery Terminal Brush PTT W147C | Buy Online - NAPA Auto Parts

New clamps can often get a skin of corrosion that won't keep you from installing them, but they can have a higher resistance if that surface layer isn't clean.




As Matt also mentioned you can do some resistance checks with the battery hooked up and the cables all attached and the truck turned off. Measure from negative battery terminal to engine block, negative connection on the solenoid, starter motor housing and see what readings you get. Positive battery terminal to solenoid stud and starter motor.

When Matt says new cables should pretty much have no resistance it should be below 1 ohm and you need to make sure your ohm meter if you have one is set to a scale that can read out in very low numbers. Tenths or hundredths of an ohm is normal.

 

Thank you Chad for articulating in a much more clear way my thinking. rtcapo, sorry to have had my wires crossed terminology wise, in my muddled mind, I spoke wrong, but no one on this site wants to mislead. Hopefully, the new info at hand will help you get your truck back on the road with reliability.

Going back to your original question, do you need to replace the cables with larger diameter cables? I think that if you were not having problems starting before, and you used the same alloy and diameter as before, then the likely culprit is not related to the cable diameter, and I would trouble shoot the other things first.

Also, I am wondering if you are dealing with a non start issue or click when the truck is warm, or cold? I had a Ford 351 in my old Master Craft, and started to get a not start or click, but only when warm. After rebuilding the starter, with a continuation of the same problem, I discovered that the problem was the Starter Rely. I assume that when you replaced the cables, you had to snug down those cables leading to and from the starter relay. Question is, could in doing so, something relating to the relay become a contributing factor?

Good luck, and please share what you find out.

 

If you have already replaced the cables and now it just clicks you need to revisit where the negative cable goes to tbe engine block. It's either greasy, corroded, painted, or just not tight enough.
you gotta really reef on that bolt so it won't turn any more. After making sure it has a clean place to make contact like Chad said. ALL battery cable connections, at battery, solenoid, block, chassis ground, starter, alternator need to be clean and tight. Make sure your battery is charged too. If you keep clicking that solenoid you will cook it.
As for the strap you inquired about I think that you are thinking a ground strap from engine to chassis. That can't hurt. When I was doing the electrical in my 65 I added extra grounds everywhere.

 

I suggest that perhaps you should revisit ohms law for the I^2R effect. I always use the biggest cable I can find,. The more resistance the more power loss, that is why transmission lines have high voltage with large conductors. 12V/2R=6 A, 6V/2R=3 A, 12V/1R=12 amps. Changing the voltage or resistance changes the current in Amps. The reason voltage drops over a distance is because of the resistance. The larger the conductor, the lower the resistance thus the more current in amps.

 

Let's examine wire gages, the lager the number up to 0 the smaller gage. #1 is larger than #2, than #4, than #6 than #10, extra. When we get to 0, then 00 is larger, than 000 is larger and finally when we get up to 1,000,000 kcmils or more than we start to have transmission lines or in my case renewable energy conductors. A 0 conductor will have more current than a 1 or a 2. Someone else said check the chassis connection. In fact check all connections. I always use oxidation inhibiter for all my wire connections. That is all the little packet of paste they give you when you get a battery. It prevents oxidation or resistance in the wire connection. If you replaced a #1 conductor with a #2 conductor, you are creating more resistance, not less, therefore less current. Just because you changed something, does not mean it got worse, just something else was about to change.

 

Check your connections, particularly at the starter solenoid. On the solenoid there are nuts that hold the cables onto the studs. On most solenoids there are also nuts inside the cables that hold the studs into the solenoid. Take your cables off and make sure the inner nuts are snug. Do not tighten the inner nuts, just snug. Reinstall the cables. Go back through all the connections and snug the nuts down. New cables will sometimes compress a bit after installation and get a bit loose. Good tight connections are necessary before diagnosing anything else.

 

I just re wired my 64 F600 with #2, I added some extra grounds, battery to bolt on frame, frame bolt to starter bolt, (used a stud with more threads to add ground), then starter stud to body, (used #8 here). My starter is the inertia drive rather than the solenoid style, not sure if it draws the same current, PO was having trouble with it all, starter was ok when tested, wires were the issue. What are you all using for starter relays?, since most are import, would like to get a spare/HD one.

 

You are talking about pure resistive loads where some of these circuits in a vehicle have an electromechanical device involved. A starter motor is not a purely resistive load, it's got winding resistance, inductance, magnetic field strength, mechanical load, and back-EMF. A starter motor reacts to reduced voltage - when RPM drops the back-EMF collapses - causing current to increase. You could run 0000 gauge welding cable, and the starter would still behave the same way if the supply voltage sags under load. The cable only affects how much sag you get — not how the motor responds to it.