6-Volt Jump Start

[SoCal32]

I posted this on the 12-volt conversion thread but thought this might be better. As someone that just picked up a restored '47 Sedan that is still 6-volt, my concern was jump starting if away from home (can't always park on an incline). What's the proper procedure with the positive ground 6-volt system if jumping with a 12-volt source?

[OhioRick]

You can hook up 12 volts directly to the 6 volt starter to turn the engine over.
Many 6 volt starters are run in 12 volt conversions for years with no issues.

[69a]

OhioRick is correct. Connect the doner battery first. Put one lead anywhere on the body (ground terminal on the battery is fine) and the other lead you can just hold firmly on either end of the cable that between the solenoid and the starter. Starter will start cranking as soon as you make contact. That cable is isolated from your 6 volt circuit unless you hit the starter button.

[JayChicago]

But of course don’t forget about the reversed polarity on your positive ground old car. The red positive jumper cable will go to your positive (ground) battery post. The black negative jumper cable goes to the starter.

Also don’t forget to turn-on the ignition switch. Ignition circuit will still be fed by the depleted 6 volt battery.

Also make sure the car is in neutral before sending power to the starter.

[RalphG]

I don't think the polarity makes any difference when boosting with a 12 volt battery. I just connect one cable to the starter side of the solenoid, other to ground and then touch the booster cable end to the 12 volt battery. With ignition switch on of course. The starter will turn instantly and at least twice as fast. You have to be fast dropping the cable end once the engine starts and hands on the choke and throttle to get it set to run right. I've done it on the 52 Merc a few times when the six volt battery was a bit too weak. Its a lot easier if you have a helper. Some video of mine.
https://youtu.be/YC_daLVs274

[Kube]

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Originally Posted by JayChicago

But of course don’t forget about the reversed polarity on your positive ground old car. The red positive jumper cable will go to your positive (ground) battery post. The black negative jumper cable goes to the starter.

Also don’t forget to turn-on the ignition switch. Ignition circuit will still be fed by the depleted 6 volt battery.

Also make sure the car is in neutral before sending power to the starter.

Jay, I'm glad you'd posted your response. I believe many folks get confused when jumping a negative ground vehicle to a positive ground vehicle.
Positive always goes to positive regardless of grounding.

[J Franklin]

Don't forget they also can be started with a good ole hand crank! I believe.

[tubman]

If the 6 volt battery is completely dead, the "Cable to Starter" probably won't work. In such a case, connect it to the battery, but make sure you have all of the lights and accessories turned OFF.

[big job]

don't pay attention to pos or neg grd. jump the battery. The extra 6 volt will not hurt anything as long as you remove cables fast enough like if you are luckey to have a push button on the solenoid.

[Merc Cruzer]

Why don't the companies that make the portable jump start batteries, make one that is both 6 volt and 12 volt? Or some enterprising sole make an adapter, that you could put on one, to reduce the voltage down to 6 volt?

[RalphG]

Originally Posted by big job

don't pay attention to pos or neg grd. jump the battery. The extra 6 volt will not hurt anything as long as you remove cables fast enough like if you are luckey to have a push button on the solenoid.

I don't know if this falls into the category of old wives tales but many years ago I was warned to never boost a six volt battery with a twelve volt battery or it could blow up the battery showering you and your vehicle in battery acid. That is reason enough for me to by pass the six volt battery when boosting with twelve.

[FortyNiner]

Originally Posted by big job

don't pay attention to pos or neg grd. jump the battery. The extra 6 volt will not hurt anything as long as you remove cables fast enough like if you are luckey to have a push button on the solenoid.

This has been my experience - 12v jump, don't dawdle, zero issues.

[69a]

Originally Posted by RalphG

I don't think the polarity makes any difference when boosting with a 12 volt battery. I just connect one cable to the starter side of the solenoid, other to ground and then touch the booster cable end to the 12 volt battery. With ignition switch on of course. The starter will turn instantly and at least twice as fast. You have to be fast dropping the cable end once the engine starts and hands on the choke and throttle to get it set to run right. I've done it on the 52 Merc a few times when the six volt battery was a bit too weak. Its a lot easier if you have a helper. Some video of mine.
https://youtu.be/YC_daLVs274

That is correct!

[Merc Cruzer]

RalohG,

Get yourself one of these and leave it hooked up (I would guess you have power to the building) when you are not driving the car. It will bring your 6 volt battery back up to speed, and you will be good to go the next time to want to start the car.

The cold is not friendly to that 6 volt battery, as you know.

Good video.

[petehoovie]

Originally Posted by Merc Cruzer

RalohG,

Get yourself one of these and leave it hooked up (I would guess you have power to the building) when you are not driving the car. It will bring your 6 volt battery back up to speed, and you will be good to go the next time to want to start the car.

The cold is not friendly to that 6 volt battery, as you know.

Good video.

[RalphG]

Originally Posted by Merc Cruzer

RalohG,

Get yourself one of these and leave it hooked up
Good video.

Thanks, I've been thinking about something like that or maybe a solar powered tender. Although at almost nine years old maybe my battery is reaching the end of its best before date.
Its -30F here tonight so I won't be trying to start anything. Been enjoying your Mercury driving videos with the top down Very scenic.

[Big hammer]

Originally Posted by Merc Cruzer

Why don't the companies that make the portable jump start batteries, make one that is both 6 volt and 12 volt? Or some enterprising sole make an adapter, that you could put on one, to reduce the voltage down to 6 volt?

The jumper boxes are not designed to crank a dead car, they are designed to put electrons back into your dead battery 6,8,12 volts. My SIL was using my jump box, he didn’t follow the instructions on the box, he destroyed the box , the tiny little battery CAN NOT crank a dead vehicle period !

[Merc Cruzer]

Originally Posted by RalphG

Thanks, I've been thinking about something like that or maybe a solar powered tender. Although at almost nine years old maybe my battery is reaching the end of its best before date.
Its -30F here tonight so I won't be trying to start anything. Been enjoying your Mercury driving videos with the top down Very scenic.

It is absolutely balmy here this morning at 3 degrees F, compared to you. Only 69 days until Spring. Looking forward to making another video this year. I should have made one in the Fall and I could have been working on it now.

Stay warm.

[big job]

Originally Posted by FortyNiner

This has been my experience - 12v jump, don't dawdle, zero issues.

True and why do I need a jump? Because of that stupid heater switch YES the knob lights up only at night. I should get a relay to the ign switch for this habit of turning knob to the left and that is low so on all night ugg

[Merc Cruzer]

Just take the bulb out. My Electro-Vac has a lighted switch. If yours is the same, just pull the knob straight off and then take the bulb out.