Jump Starting?
 

Hi Everyone!

I think I've almost had enough fun fiddling with the chassis grounds, coil, distributor, generator, wiring harnesses, lights, horn, starter, fuel sender, fuel gauge, and ammeter in our car.

I was wondering:

What are the dangers and techniques for Jump Starting an old Ford original 6v positive ground, generator equipped system with a 12v negative ground alternator equipped modern vehicle?

Is there any device that can be used to make this trick safer for the vehicles?

Do you need heavier gauge wire in the jumper cables?

Is there such thing as a 6v jump box? Reading some message boards seems to indicate they may not be. Would carrying a 6v motorcycle battery be a substitute for a similar 12v jump box?

In auto-shop, we teach to hook the fourth connection from the good negative, to chassis ground on the dead car. This hardly ever works because of poor grounding. And grounding in the 6v system is even more important, isn't it?

-VeryTangled/Jeff

Re: Jump Starting?
 

when using a 12v jump put the pos cable on ground. then just touch the starter side of the sol or the starter post with the other cable .this way the onley thing geting 12v is the starter.whitch car take it. ps don,t forget to have ign switch on

Re: Jump Starting?
 

Iv done it in a pinch and had the same worry’s … nothing bad happened. Maybe I got lucky and im not sayin it’s the right thing to do.

Re: Jump Starting?
 

If using 12V to jump a 6V car only hook the jumpers up when the starter is engaged, also be careful and make sure all lights are turned off, this can be a quick path to all new bulbs.

Re: Jump Starting?
 

Ive jumped from 12V car many times,never had any troubles,Just make sure everything is off except ignition switch and do it quick,it should start real quick if its only the low or dead batt. And disconnect right away as soon as it starts. ken ct. OMO.

Re: Jump Starting?
 

If you follow the advise posted by Richard, there is no possibility of 'hurting' anything on the 6V side of the car. The ONLY thing that sees 12V, is the starter, if done this way. Problem is, many people don't understand this, and simply hook 12V across the 6V bat. For this scenario, usually nothing bad happens, but there is always the possibility that 12V can hurt the ignition system, or anything else that is turned on.
I choose to stick with Richard's way, noting that there must be at least enough 6V available to run the ignition (since it doesn't get 12V using this method).

Re: Jump Starting?
 

From the pictures i,d say call AAA.
If you think it will start.
Remove the small wire to selinode.
Next take the neg cable from 12 volt battery and put on starter.
next take cable pos to pos ground.
Now take the other of cable and touch to battery.Turn ign on,Be carfull the battery does,nt blow up.
If it does,nt start right up get ignintion working first.

Re: Jump Starting?
 

This way would not have worked for my second jump Saturday morning (read here: http://www.fordbarn.com/forum/showthread.php?t=93137 ) because the battery was too dead to even fire the coil. Had to jump battery to battery as others have said. Connect batteries while starter button is pushed in and disconnect as soon as starts. Always works fine. (Of course, I always push start it if I can before resorting to a jump from 12 volt.)

Re: Jump Starting?
 

Yes. I bought the longest beefiest cables I could at NAPA. Anything less and you've got smoke and melting pretty quick jumping from 12 volt.

Re: Jump Starting?
 

Thanks everyone for getting this rolling. Please, more comments.

So far, I get this much. Please correct all of this as you see necessary.

Make sure the dead car is in neutral, with the parking brake set and wheels chocked.

The good car should be turned off, and have itself secured (probably in Park) with the parking brakes set. You should never have to start the good car, it should have plenty of cranking power. Besides if you do start it, that seems to increase the chance of blowing ITS computer, turning the helper's good deed into their nightmare and your ulcer. I guess if you want to be ultra-safe you could disconnect the good car's negative battery terminal (requiring a tool), but be aware this will likely upset the car's computer/radio/alarm/seats/backup-camera/auto-parking system/transwarp-drive/etc.

Dead car: Turn everything off. All lights, blowers/motors, radios, even shut the door if you have a dome light. Don't turn anything on until the cars are disconnected. Unplug all accessory adapters and aftermarket stuff. (Editor: If you have a battery cut-out, and haven't turned it on yet, then go directly to Jail. Do not collect $200.)

Good car: Red onto positive battery terminal.

Dead Car: Red onto ground (chassis, block, starter case/bolt? Advice please.) Both red hook-ups are done, to be removed after start-up, remove it from the dead car first when the time comes.

At dead car black onto starter post/battery negative. (Note: One connection is not hooked-up, black to the good car's negative battery post. Controlling this cable from the good car end of things is safer than trying to make this momentary connection while starting the car in the engine compartment of the dead car.) Some seem to indicate it's okay to go the battery ground terminal vs. the starter post, yes/no? Connecting to the battery seems to expose more of the bits to being blowed-up, but the battery disconnection will be easier to do than from the starter post (of a running engine:eek:, even though it's away from the spinny pieces). A thought: Can you get to the starter post from under your car? Maybe you feel this is a safer place to reach under and disconnect after the car is running. (Remember chocks/brakes please.)

Dead car: Switch on

Dead car: Starter on

Cable-person/Helper will momentarily touch black coming from the dead car starter/battery to the good car's battery negative terminal. (Starter should spin rather well?) Cars are connected, hopefully for the shortest amount of time possible.

Caution: When lead-acid batteries charge/discharge they off-gas hydrogen and oxygen, a combustible combination. Try not to make too many sparks nearby lead-acid batteries, such as when you touch the cable to this negative post of the good car. Touch the connector with force and confidence. Oh yeah, they're called lead-acid because they have a sulfuric-acid solution in them. :( Not something you want to a) wear, b) clean-up.

When it starts: Cable-person/Helper will quickly remove good car black from good car battery negative terminal. Cars are disconnected (but keep track of the end of that cable for a few more moments, don't touch it to any metal surface). Release starter button like you normally instinctively would.

Keep it running.

Remove dead car black cable from starter post/battery. Black cable is now safe.

Remove dead car red cable from previously selected (positive) ground.

Remove good car red cable from battery positive terminal. Both cable ends are now safe.

Cautions: While doing this be aware of fans, belts, pullys, and dangly things even/especially hair/headwear/neckwear/jewelery. If you have gloves and protective eyewear they might be a good things to put on. (Note to self: put these in the back of the car now.) Check one more time to make sure the car is in neutral, with the brakes set.

Is there any way this is not a two-person job, it seems you need a 'starter' and a 'cable-person'? The cable-person job can be made safer depending on where you hook-up (and on who the starter person is... Check the brakes/neutral again. please.).

Any comments on 6v jumper cables vs. 12v cables? [Edit: Sorry, was off writing when Prof. Henry's above post came through.] How about the idea of just carrying a motorcycle battery in place of a hot-shot would they have enough amps to get a satisfying crank?

-VeryTangled/Jeff

Re: Jump Starting?
 

I think to much knowlege is bad for a simplie, start and run problem.
Buy a new 6 volt battery.

Re: Jump Starting?
 

If the motorcycle battery was off of a 3,900 cc motorcycle (that's the size of the 239 cu.in. V-8 flathead) it might work. Think you can get one that big? Not likely. For a 6 volt battery to start a flathead V-8 it must have 700 cold cranking amps (CCA). Just a quick browse for the largest motorcycle battery I could find was 350 CCA - only half of what you'd need. Of course, they're all 12 volt - not too good to start 6 volt systems. Might as well carry a spare car battery but how to keep it fully charged and ready when you really need it? That's just one more thing to worry about.:(

CCA's are critical. I found that out after being sold a 6 volt golf cart battery by a "knowledgeable" NAPA guy when I first restored my car. Great big huge battery. Had to be good. Right? - to power a golf cart? NO! I soon found out that if I wanted to move my car with the starter motor the battery would move it quite a ways but to start it in the winter? not so good. Gotta have the CCA's.:cool:

Re: Jump Starting?
 

If you rewired it and have a volt meter.
1 take wire off dist.
2turn key on and the end you took off dist put neg lead,other end to grd or pos on batt.Should read 6 volts.
3 now put wire back on and leave neg test wire.
4 should read about 4.5 volts.
Don,t leave key on to long.
You better have a fire exstingihser handy.
You have to nice a car to be runnig amps wire and burn her up.
You have about 40 degs down there now get a good 6 volt battery.
Back in the day they used 10 w and put some k1 in old days.
I don,t think thats the problem.
Wireing my guess.
Every day there is a start and run problem.
Burnt coils most often.

Re: Jump Starting?
 

Hi Jeff, I am trying to figure out exactly what you are showing in some of these pictures (as viewed on my smart phone :)) and wondering if they represent a problem that just happened?
I personally do not like jumping a 6V system with 12V. This would have to be an absolute last resort option for me to even consider doing. Especially when connecting 12V directly across a 6V battery after I once had one explode doing this years ago. The option to connect one lead to the starter terminal would be the only thing I would consider if the main battery had enough charge left to fire the ignition system.
This may sound a bit extreme, but I am planning to carry a backup Optima 6V battery, jumper cables and a battery charger/tender with me on long distance tours in 2013.

Re: Jump Starting?
 

JM I doubt the battery exploded from the 12 volts. There were no doubt fumes from the battery and the spark from the jumper cables ingnited them. A dead 6 volt battery is going to pull the 12 volt jumper battery down in the 9 or 10 volt range. A larger charger puts this much voltage into a 6 volt battery initially when the 6 volt is very low. Best solution is to carry a 12 volt battery pack like I have. This has a switch and I connect the cables on the ground and starter side on the solenoid or right on the starter. Turn the ignition on, turn the switch on the battery pack which runs the starter and it starts right up. If the battery is to low for coil voiltage hook it right on the battery terminals then turn to pack switch and start it. Turn the battery pack off as soon as it starts. This pack also has an air compressor a 12 volt cigarette socket and 110 volts AC. Has it's own built in charger. Large diameter or wire size cables are best for jumpers, but the shorter the better. G.M.

Re: Jump Starting?
 

Oops. How did this turn into "How to fix my broken car?"

My real question is how do I keep from breaking my car when stranded on the road?

I put the photos in to illustrate some of the systems we have worked on in the time we have owned the car. I hoped the photos would stir some conversation. ;)

None of the systems are broken right now. Our car runs just fine right now, thank you very much. <tapping foot>

I really am feeling like JM. A spare Optima, a set of 2 gauge cables, and a 6v tender with 150' extension cord would be only thing I might be able to rely on.

-VeryTangled/Jeff

Re: Jump Starting?
 

You took the time to write this and your daddys car runs well.


LOL LOL LOL

Re: Jump Starting?
 

I don't know George, could have been ignition of fumes. If spark occurred, it happened after the jumper clamp had been connected to the battery terminal and the starter began cranking. All I remember was the 'KA BOOM!!' and feeling fortunate that I did not get hit by pieces of the case or get any acid in my face.

Re: Jump Starting?
 

Interesting subject. Growing up on a farm we always had a low or dead battery on something. We had 6V, 12V and 24V systems and had our share of explosions with battery acid and battery parts flying. This does happen and getting covered with battery acid is not good. I am gun shy using an unmatched voltage as a jumper source. I have done it many times with no problems but it's not worth the pain when it goes wrong. When you put a 12v battery across a half dead or dead 6v battery you have two batterys bucking each other. The 12v battery will over power the 6v battery and you will have current flow through the 6v battery which will get the hydrogen gass warmed up and the hydrogen fumes start to form a cloud around the battery. This sets you up for a nice big explosion if you get a spark from a generator brush or a loose jumper cable when you crank the old girl over.

Re: Jump Starting?
 

when you jump a car or truck you schould put one cable on the batt the other cable touch to ground away from the batt .this way if there is a spark it will cause no harm. i have been a mech for over 65 years i have worked for larg fleets been on thousands of road calls i have never had a batt explode on me . i can,t say that for maney of the guys i worked with. who would put both cables on the batt

Re: Jump Starting?
 

Chisel The batteries aren't "bucking each other". They are in parallel. The voltage in the low battery will increase and the higher one will decrease. You will have a voltage lower than 12 volts out with this combination. Leave them connected a while and the 6 volt battery will get a fast charge and the 12 volt one will get lower in voltage. I'm not sure a battery will explode with the caps on it takes oxygen to have an explosion. G.M.

Re: Jump Starting?
 

Yeah, go ahead and try that. I dare you.
If those batteries are hooked together for more than a few seconds there will be smoke and melting of the insulation on the cables. Believe me, I've seen it.

You're thinking of hooking a good and dead battery together of the same voltage. That may have some of the charging effect you describe. But, you can't charge a dead 6 volt battery with a good 12 volt battery. No cable will handle the current and neither will the batteries.

Re: Jump Starting?
 

Hi GM
With due respect to your vast electrical knowledge and not trying to start a pissing contest. When a battery is installed in an old car there is no current flow from the battery until the ign sw is turned on. Now you come along and hook a 12V jumper battery on a 6V system. + to + and - to - you have a series circuit. 12V source bucking a 6V source. The 12V source will over power the 6V source and will cause heat in the battery and hydrogen gas will escape the battery and if there is a spark near by--boom. As a dumb young kid jump starting farm equipment daily, I have experanced quit a few explosions.
Your method of jump starting is a safer solution.

Re: Jump Starting?
 

I highly doubt that the cables hooking those two batteries of different voltage together would last long enough to heat up the batteries. In my experience the cable heats up and starts burning off the insulation way before either battery heats up as much.

Re: Jump Starting?
 

Any else confused?

Re: Jump Starting?
 

Old Henry
The jumper cables we use are home made. 4/0 welding cables 16' long with copper clamps and the batterys did get hot.

Re: Jump Starting?
 

Ah, now them right there are some mighty fine jumper cables. I can see how they could definitely heat up the batteries.:p

Re: Jump Starting?
 

I broght that battery blowing up because i see it happen.
Try to start a 38 dodge years ago after a bearing and ring job.
Hooked 12 to starter and battery under seat so direct to starter and not knowing the fusmes could exsplode,my friend touched to battery and blow the cap off,lucky he had glasses on.
I do remember years ago before 12 volts,you could put two 6s in series.
If you have a calibreted eye ball watch your amp gauge.I like a volt meter better.
From the first post i didn,t know it was a show and tell. atboy.

Re: Jump Starting?
 

Chisel, I'm pretty sure +to+\-to- equals parallel, not series. Series changes the outlet voltage, parallel Keeps it the same (-) drop!
Chuck

Re: Jump Starting?
 

I wonder why all batteries don't blow up when a large high amp shop charger is hooked up. Check the voltage being pumped in. You don't leave these on for long periods at the high range. As stated before the explosions are from gas comming from the battery and spark ignited. I have jumped old Fords with 12 volts for many years with no explosions. G.M.

Re: Jump Starting?
 

Barners, here's what I was thinking when I started this discussion...

Prof. Henry writes very entertaining descriptions of his multi-day travels. The V8 Club is trying to promote driving events. Even the Barners Bashes, like the recent Maine tour, and Georgia tour(s) are something that interests me. There are probably several caravans that are traveling west this year. (Tipping hat to all who work behind the scenes to organize these events.)

For group tours it's not too hard to find a set of suitable jumper cables and a 6v donor car.

But in other cases we're not traveling with buddies and are not going to have the luxury of going 6v to 6v if we need a jump start.

I didn't quite say it clearly in my original post, but in my 53 years on this planet I've broken more than a few things from my own stupidity. Usually these things can be fixed with time, money, and effort. But I and am trying to learn from those experiences and be smarter.

Towards that end I thank all contributors to The Barn, and to this thread.

I can see a time in the future where I'd like to more clearly understand the most gentle techniques for road-side breakdown solutions.

So that was were I was coming from.

-VeryTangled/Jeff

Re: Jump Starting?
 

Not that I'm going out to buy some, but there seems to be a big price for some of the heavier gauge jumper cables!

I just popped over to NAPA's site (just chosen because I knew they'd have more than one to pick from).

One thing that seems important is that it makes a difference if the dead 6v battery has enough charge left to fire the coil. If it does it seems you should connect to the starter, if it doesn't it seems you should connect to the battery.

Unresolved questions: Does jump starting have to be a two person job to minimize the time the 6v system is exposed to 12v?

Are there any portable hot-shot solutions for 6v?

Where are good attachments for the dead car's positive cable? Nominees are: Battery positive, unpainted chassis, starter mounting bolt, starter case.

Will the starter spin faster or with more torque when hooked to the 12v system?


-VeryTangled/Jeff

Re: Jump Starting?
 

The starter spins much faster with a STRONG 12 volts. The engine will also get a stronger spark. Also a set of 12 volt jumpers are usually very small wire size. The heat you feel in these cables is like a resistor and causes a voltage drop so you don't get 12 volts any way. Solution,12 volt battery pack with a built in switch, no current to the cables until the switch is turned so you can hook it up to the starter and a good ground, turn the ignition switch on THEN turn the battery pack switch to spin the starter. Even with a low 6 volt battery there should be enough voltage to fire the coil as the coil volyage is not being pulled down by the starter. The engine will start with a crank, pushing by hand or coasting down a grade for the same reason, no voltage drop from the starter load. More fuel will also be pumped spinning the engine on 12 volts. You can also check the oil pressure spinning on 12 volts, mechanical gauge, remove the plugs and the oil pressure you see will be the oil pressure driveing downthe road. G.M.

Re: Jump Starting?
 

Hi G.M. Thanks for helping.

Does your jump box have something like the switch on this one? Having the switch seems a good idea.

What Make/Model is yours, if it's close by?

This one has 4 gauge wire, comments anyone?

-VeryTangled/Jeff

Re: Jump Starting?
 

Main comment - this, again, is a 12 volt jump box. Not ideal for 6 volt.

Again, of all of the times I've had to start my car with a dead battery, 90% of the time it's by a quick push - not a jump. As others have said, battery jump is a last resort when pushing just won't do.

Re: Jump Starting?
 

It does unless you hook up a remote starter trigger to the starter solenoid so that you can run the jumper cable clamp and the starter at the same time.

I've always clamped right onto the positive battery post clamp - eliminates any weak connections between that and other alternatives. Even then, I really have to "work" that clamp contact to get it to really contact (wiggling, etc.) I've never tried directly to the starter terminal because it's so awkward and inconvenient compared to the battery post.

Re: Jump Starting?
 

When a battery is fully charged, it will start producing Oxygen and hydrogen gas.
from the water in the battery (H2O);and that gas mix is very explosive.

Thats the reason you always connect the positive post's on the two batteries.
and then connect the last Connection to Earth somewhere on the Engine or body.
Not on the battery post, preventing to get at spark igniting the explosive gas.

This is for a car with Negative Earth.

Avoiding sparks is the name of the game.

I have started 6 Volt cars with 12 Volt and even with 24Volt. and used the method above.

Keeping the Connection time as short as possible helps.

Re: Jump Starting?
 

The best answer i can come up with is carry another 6 volt battery.
Up here in the north are plows have a quick disconnect.
The end before stater wire put a selinode,and wire a push botton in dash.
Other end to frame.
Now you need the male end on battery.
Quick disconnect Made for Fisher plows.
Now if you have a dead battery with no power to start you have a spare battery.
Or call AAA

Re: Jump Starting?
 

I agree with this too. In your recent cases, #1 thick oil/very cold, and #2 warm, but not enough charge to spark the coil, I have been able to learn from your contributions.

I think I like the idea of carrying a starter switch, they are small enough and useful for other electrical troubleshooting too.

One thing I experienced after installing a battery cut-out switch is that you can roll-start a car with the battery cut-out in the off position. You will get the thing started but it will break the coil pretty soon. <Skip I owe you some money.> So even when roll-starting there are pitfalls.

I was thinking about your situations though, in neither case was rolling or pushing helpful. Have you noticed any ill effects from the trip?

Enjoying the conversation.

-VeryTangled/Jeff

Re: Jump Starting?
 

Henry no pushing for Me .I wouldn't want dents etc ,Jumping is a one man job, and one of the easer things to do on a flathead ,done it hundreds of times .on a 47/48 Whats wrong with hooking up to the starter side of the solenoid you will get a few sparks ,use a charger on the 6 volt if its completely flat .If you plan on hooking to the battery be sure to ware some high strength goggles ,My 78 year old friend can see like a cat now because of a battery explosion,he has got a new retina ..