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post #1 of 18 Old 01-04-2012, 12:50 PM Thread Starter
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1973 CJ5 
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Cold weather starting...

This keeps coming up, does every year...

CA Vs. CCA rated batteries.

'CA' (Cranking Amps) is rated at 32F (0C.)

'CCA', (COLD CRANKING AMPS) is the industry standard in the US, and it's rated at 0F. (-17.7C)

Since your battery has a LOT of 'Water' in it, the difference between 32F. and 0F. is SUBSTANTIAL.

Normal lead/acid batteries have a 'Tipping' point where they loose power VERY QUICKLY, and that tipping point is between 32F. and 0F.

The chemical energy stored in your battery releases MUCH SLOWER below 32F. and drops off VERY QUICKLY after that point.

The truth of the matter is,
At 0F. your battery is putting out about 1/4 of the current it should, and it's VERY SLOW to convert the chemical energy into electrical energy,
So it doesn't produce CURRENT, (Current, value of combined Amperage & Voltage) nearly as well as it does at a reasonable temperature.

*IF* you live in cold winter climates, look for a battery with a HIGH 'CCA' rating, and avoid the batteries with a 'CA' rating instead of 'CCA' rating.



Doesn't matter how large the output of the battery at any given temperature,
If you don't have cables large enough to handle the amperage the battery will produce, you aren't going to turn that starter!

The little WIRES used by the factory, 8 Gauge or 4 Gauge generally,
Are NOT enough to supply a starter in the winter, and barely adequate for a 'Hot' start in the summer.

A good set of CABLES will serve you much better than 'Wires' will.

WELDING CABLE, designed to handle AMPERAGE every day, all day long, will do you much better for a 'Hard Start' than the 'Wire' from the factory or some 'China' replacement source.

'China' wires are NEVER virgin copper, they are always alloy that doesn't carry amperage as well.
I don't know why 'China' can't figure out copper is the conductor, and anything else in the copper is resistance, but I've never seen a 'China' wire that wasn't alloy instead of virgin copper.

Welding cable is FINE STRAND, so it carries more amperage for the same cable size/gauge.
Welding cable is wound as CABLE, not 'Wire' which is just a spiral twist,
So they last MUCH longer,
And welding cable has insulation that is intended for hard, heavy use in contaminated environments, resists abrasion better, and generally works MUCH BETTER in Jeeps.


What most people are used to seeing is a smashed piece of tubing you crimp onto the wire.
THIS IS NOT 'GOOD ENOUGH' for long term use/abuse in a Jeep!

No matter how much the smash the tubing, there is still a passage from the terminal end up to the cable, and moisture/corrosives will enter!

The smashed tubing type usually DO NOT have a large contact patch to your terminals at the starter solenoid or the starter motor.
The larger the contact patch, the more current the terminal will transfer to your electrical load...

When you make the terminal connections,
1. Crimp.
Moisture WILL creep into the cable/connector and ruin your ELECTRICAL CONNECTION OVER TIME!

Seals out the moisture from contact points,
Closes up the potential for moisture to creep in from the 'Smashed' end,

Silver solder helps, but there is nothing like a good GLUE SEAL on heat shrink tubing to keep the moisture/oxygen/corrosives out of the cable bundle!

Meaning the material on your smashed tubing terminals is THIN AROUND THE 'EYE' HOLE,
There is a way to increase your connection surface area, and it costs 2...
Drill a hole in a PENNY, ('82 or older) and use one on both sides of the terminal.
'82 & older pennies are 95% to 98% copper, and when soldered onto the terminal end faces, will increase your contact area several times over and they are cheap and last a good long time!


STARTER RELAY ('Solenoid'),

Starter relays are like anything else, the 'Replacements' are made in 'China' or where ever, and they are CHEAPLY BUILT.

The average starter relay will come with 'Steel' terminals, which will pass about 170 amps on a good day...
The steel often carbons up where the electrical contact happens, and they pass MUCH LESS current when that happens...
(Go figure, you introduce CARBON steel to an electrical arc, then seem surprised when the carbon builds up on the contact surface as the steel gets burned away!)

While if you seek out a BRASS or COPPER terminal relay, they will pass up to 320 Amps and live MUCH longer.
An added benefit is most of the better relays have silvered or copper contacts silver soldered onto the terminals inside, so they don't carbon up/warp/burn away as fast and live MUCH longer, passing more amperage the entire time they live...



Most of you have the short 'Ground' cable to the engine block or head.

When you replace the wires for 'Cables',
Add a little to that 'Ground' cable and move it to a starter mounting bolt.

Since your starter is by far the LARGEST electrical draw in the system,
Why torture it for electrical 'Ground' through the engine block bolt, engine block, bell housing bolts, corrosion on the bell housing, rust on the block, then through the starter mounting bolts and finally to the starter body it's self?

Since it's the LARGEST ELECTRICAL LOAD, doesn't it make sense to add a foot of cable and run the 'GROUND' right to the starter so it doesn't starve for 'Ground'?
I mean, if the starter can't complete the circuit efficiently, it's simply not going to work efficiently...



If it's putting out at full value and you have reasonable cables/relay, you WILL crank the engine!

The draw backs are,
You have to have some place to plug it in...
That doesn't help you if you park in a parking lot without power,
Or forget to turn on the heater about an hour before you try to start the vehicle.

If you go out hunting or whatever and let the vehicle sit all day in the woods, you will be back to a single battery and a hard to start engine...


The second most effective thing you can do is put a SECOND STARTER RELAY IN SERIES WITH THE FIRST.
This is cheap, easy to do, and DOUBLES the battery output through the relay.
Normally, when you have a good battery, and good cables,
The starter relay will be the 'Restriction' in the system.

The battery might be rated for 750 CCA,
And you have cables that will conduct a good amount of that 750 CCA to the starter,
But the relay will only pass about 170 to 320 amps or so on a good day...
By DOUBLING the starter relay, you DOUBLE the amperage to the starter for about $12 and a little wiring...
(It's also a 'Redundancy' thing, you don't get stuck when a starter relay gives up since the second will take over and start the vehicle...)


Another way to do things is to have more battery in the first place.
DUAL BATTERIES, wired through DUAL STARTER RELAYS, will deliver TWICE the amperage to the starter.
This requires some extra expense,
Cables for TWO batteries, A dual battery tray, The second battery it's self, and if you wire it correctly, a second starter relay to deliver that battery current to the starter without choking it off in a single starter relay...



While your battery is down to about 1/4 power output,
Your engine is roughly 4 times harder to start.

Cold, wet combustion chambers from condensation,
Thick cold air makes spark harder to start in the plug gaps,
Cold fuel doesn't like to atomize properly in cold engines, so it runs into the chambers as liquid fuel,

Metal contracts when cold,
So you have crank, rods, pistons, camshaft that don't like to turn in their bearings,

Oil (and oil pump) hate cold weather, they are consuming MUCH more energy to turn and circulate the oil than in 'Warm' weather,

A 'Block Heater' will warm the core of the engine some, but you are back to being tethered to a 110 volt outlet for that to work...
And if you are only running a block heater, the battery is still very cold and only putting out about 1/4 of the amperage it should.

Running a 'Thinner' oil in very cold climates will help some,
I usually run 15W40 in three seasons, but the Jeeps I drive in winter get 10W30 in the winter, and it does help a little bit...

A more 'Practical' way to do things for a vehicle that isn't going to have a plug in available all the time is to upgrade the battery (batteries), cables, starter relay(s) and fix the 'Ground' issue to the starter...



With all the things working against you when it's very cold,
One thing you can do is something that helps you all year around...
An ignition upgrade...

We all know by now about the factory ignitions, and the potential 'Upgrades' available,
But I can't stress enough how they will help you in the cold of the winter getting things started!

The environmental conditions in the combustion chamber is PITIFUL,
HOSTILE would be a better description...

With a GOOD IGNITION, and better power to the ignition/starter, at least you stand a fighting chance of getting some cylinders to fire and get things running!

One of the biggest reasons an engine WILL NOT FIRE in very cold weather is the starter is consuming everything the battery will produce,
So voltage drops well below the threshold that will fire the ignition properly.

*IF* The starter consumes more amperage than the battery/cables/relay will supply, the voltage drops considerably...
And your ignition needs around 10 volts to fire at all.
When the starter is turning the engine VERY SLOWLY, that starter is virtually a 'Dead Short' and that will drop the voltage to well below what is required to fire our electronic ignitions...

So even if you can get the engine to crank VERY SLOWLY, all you are doing is draining the battery, heating up the starter, and the ignition still isn't firing reliably, if at all...

That SECOND BATTERY discussed earlier would solve all these problems pretty quickly,
And if wired through a second starter relay, even better solution to the low amperage problem to the starter!

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post #2 of 18 Old 01-04-2012, 03:10 PM
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Whats a good place to get some beefy battery cables?
Could AMP cables for a subwoofer be used?
I have a 0-1 gauge cable for my subs amp... its almost as big around as a hotdog... it was not cheap by any means!
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post #3 of 18 Old 01-04-2012, 03:16 PM Thread Starter
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You are better off with welding cable from any welding supply store, or even NAPA if they carry good size cable where you are.

The insulation alone on the speaker cables I've seen would keep me from using them...

I don't want to piss anyone off, but stereo cable is mostly for show, not 'GO'...
And virtually all of it comes out of 'China' so it's alloy rather than virgin copper.

I live with virtually the same kind of winters you do in VA., and 4 Ga. WELDING cable has worked well for my starter here.
If I lived in any colder climates, I would up side to 1 Ga. or even larger the colder it got.

Just switching from 4 Ga. 'Battery Wire' to 4 Ga. Welding Cables increased the amperage to the starter about 35% or so...
But I did use the heaviest terminal ends I could get my hands on also, and I'm sure that had something to do with amperage delivery.
The factory 4 Ga. 'Battery Wire' had PITIFUL terminals on it...
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post #4 of 18 Old 01-04-2012, 03:25 PM
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Lol, I agree on the china crap, but I ought to post a pic of this cable, its very fine strand high quality stuff. But the sheathing is definitely not meant for mud, oil, gas, hardcore solvents and abuse. So 4-gauge is plenty big you think? Im tempted to go for 2-gauge, just because.
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post #5 of 18 Old 01-04-2012, 03:27 PM
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Also would you mind throwing up a pic of your cable setup? Can the welding shop or napa put good terminals on the cable for me?
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post #6 of 18 Old 01-04-2012, 03:57 PM Thread Starter
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2 ga. is a bullet proof way to do things,
If you want to see the cables I use, try the winch threads in my signature line.

Napa or Welding shops will crimp the terminals on for you if you buy the cable and/or terminals there,
But you will still have to break out the torch and get some ELECTRICAL SOLDER (preferably silver bearing solder for fine electrical connections) and solder in the ends once crimped, or you will leave space for corrosion to get started...

There is also something called 'Tinning' the cables...
(gets it's name back when solider had a lot of tin content).
You solder over the exposed wire between insulation strip and connector.
That will help keep the corrosives out of the wire bundle,
BUT BE CAREFUL, you CAN over do the solder in the wire bundle and wind up with some REALLY STIFF wire!


NOTICE the heavy duty terminals I use,
These are SOLID COPPER, with a corrosion resistant lead cadmium plating.
These are NOT cheap or easy to crimp, but they will keep working when EVERYTHING ELSE has failed...

NOTICE the 'Red' battery cable, wires all twisted the same direction on the LEFT,
And the Welding Cable on their Right, with counter twisted bundles and much finer strands, 'Black' insulation...


If you strip too short, the wire won't reach the bottom of the terminal and you loose contact area/amperage carrying capacity,
Strip too long, and you wind up with a big open spot for contaminants to enter the cable bundles...





Oxygen, Water, Corrosives can enter the cable bundle.


See the flattened end of the tubing terminal? See the highway for corrosives to enter the terminal/connection?

When you solder the flattened terminals, you close up the gaps and corrosives can't enter the connection. I usually cut and drop some solder in the terminals before I put the wire in when I'm using the flattened tubing type just to make sure that gap gets sealed!
Cheap way to make cheap terminals more useful and long lived.


STARTER RELAYS ('Solenoids'),
These corroded steel terminals were passing barely 75 amps, and will only pass about 170 amps when brand new and shiny,
While the Copper Terminal version will pass about 320 Amps on the load tester!

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post #7 of 18 Old 01-04-2012, 05:12 PM
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Good stuff, thanks Hammer, if I didn't solder or tin the wires for protection, would liquid electrical tape or silicone sealant be an ideal way to seal or contaminants?
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post #8 of 18 Old 01-04-2012, 05:55 PM Thread Starter
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Silicone sealant uses an acid based (Vinegar smell) and that will attack your wire faster than the weather will.


I don't know about 'Liquid' electrical sealer, haven't use it much, so I don't know what it will do over the long term.

Any welding shop or usually NAPA or any big truck supply store will have the proper heat shrink tubing, but it's not cheap...

Most of the nut and bolt stores will have a source for heat shrink also.
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post #9 of 18 Old 01-04-2012, 06:16 PM
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Tractor Supply is a good source for welding cable (by the foot) and electrical needs as well. Great write up as always Hammer!
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post #10 of 18 Old 01-04-2012, 06:23 PM
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Originally Posted by JeepHammer View Post

STARTER RELAYS ('Solenoids'),
These corroded steel terminals were passing barely 75 amps, and will only pass about 170 amps when brand new and shiny,
While the Copper Terminal version will pass about 320 Amps on the load tester!

JH, regarding the two Solenoids. The front two wires (engage/run as it were) on the solenoid, those only stay on the one or do you splice into the second solenoid? I was thinking the second solenoid was contact continuity/electron flow, am I right, or do you need to triggers on the second one as well.

OOPs, brain fart over after seeing what I wrote, you would need to triggers to make the solenoid contact to flow the electrons, right.

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post #11 of 18 Old 01-04-2012, 09:36 PM Thread Starter
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I use one relay per battery, with both outputs combining to go down to the starter.

When you use ONE battery and two relays, you jump the battery cable from input on one to the input on the other,
Then connect the two outputs down to the starter.

Same with jumpers for 'Blue' and 'Red' small wires from one relay to the other.

Sounds a LOT more complicated than it is...

Both relays feed the starter,
Both supply the ignition (Small 'Red' wire),
Both trigger at the same time this way (Small 'Blue' wire)...
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post #12 of 18 Old 01-04-2012, 09:39 PM
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Thanks, thats what I thought but then again I was thinking I was also crazy.
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post #13 of 18 Old 01-04-2012, 09:59 PM Thread Starter
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Anyone that CHOOSES to work on one of these old rust buckets is completely NUTS!


What people now days aren't used to, and I remember WELL since I was always the sucker that got sent out to start the vehicles when it was REALLY COLD...

Was that in the 'Good Old Days', things just didn't run when you wanted them too!
Back in '73 when mine was new, with breaker points,
EVERYONE Had their own way of getting things started,
Some used jumper cables, some used starting fluid, some just cussed and pumped the throttle/ground on the starter until the battery was completely dead and went back to bed!

Since electronic ignitions and fuel injection, we all expect EVERYTHING TO START RIGHT UP!
And when you are dealing with a 30 year old vehicle, sometimes that just doesn't happen...

Between old batteries, old cables, old relays, old starters and old engines, sometimes that 'START RIGHT UP' not only doesn't happen, but it won't start at all!
And if you are lucky enough to get it started, there are no guarantees it will stay running...

I'm just trying to show you how to get it cranking,
Once cranking occurs, the start/run is entirely up to you!

I've posted choke adjustments, battery & starter upgrades, ignition upgrades and tuning.
Hopefully, some, or all of this will help most of the guys get the old clunkers running when they need them!
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post #14 of 18 Old 01-05-2012, 01:47 PM
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+1 on the welding cable. My brother significantly increased the cranking RPM on his diesel Jetta doing this. Think he used a 2/0 section of old welding cable from work when they got new cables.
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post #15 of 18 Old 01-10-2012, 12:38 PM
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Went to the welding shop today and looked at some cable, they have 2-gauge, and they also have 2/0
The 2 gauge is about the size of my pinky finger...
The 2/0 is about the size of my thumb... which should I go with?
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