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Here I go again ..... to 12V or not 12V
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Greeney in France



Joined: 06 Mar 2008
Posts: 1173
Location: Limousin area of France

PostPosted: Tue Oct 14, 2008 8:38 pm    Post subject: Reply with quote

On the Traction there is a large space under the dash where the loom connects to a 10 terminal bar I have bought an 8 way fuse box for this area. I am not a purist by any means but would prefer it to be safe and still look good
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Kaybee



Joined: 27 Dec 2007
Posts: 147
Location: Croydon, Victoria, Australia

PostPosted: Sat Oct 25, 2008 10:08 pm    Post subject: Reply with quote

Rick wrote:

I'm toying with the idea of putting the Dodge on 12v (only toying with the idea at the mo!!) and I'd rather stick with the factory twin pulley dynamo, than something that would look a bit out of place

R


Hi Rick, my old Dodge Weapons Carrier was 12 volt from the factory , so a correct 12 volt generator and large Military regulator does exist for these models, maybe a bit of searching on US Ebay or some of the military sites/forums will solve your problem, cheers, Col.
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Rick
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PostPosted: Sat Oct 25, 2008 10:23 pm    Post subject: Reply with quote

Thanks Col, yes I've been wondering about which regulator would be needed if I did do the switch!

ta, R
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Nic Jarman



Joined: 05 Oct 2008
Posts: 1031
Location: Stoke by Clare, Suffolk

PostPosted: Tue Oct 28, 2008 9:28 pm    Post subject: Reply with quote

I think a moment of clarity is called for. It is simple, if one is drawing 10 amps then use 15 amp cable and use a 13 amp fuse. OK call it 6v at 60 watts = 10 amps. The fuse will pop at 7.8 volts which is a surge of 28 watts, where does this extra energy come from. It is true that bad connections that make and break can cause spikes but it is the resistance in the connection that is more of a problem as it produces heat. This is also true for fractured cables as happened on my battery lead where the flexible cable joins the ridgid clamp ( know as the fracture point). What the fuse is there for is if a wire shorts out and the battery throws as much current as it can to set your car on fire. The battery acts as a vey good voltage regulator and it is bad practice and poor mainenance that cause these problems.
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Jim Walker



Joined: 01 Oct 2008
Posts: 124
Location: Chesterfield, Derbys.

PostPosted: Wed Oct 29, 2008 12:43 am    Post subject: Reply with quote

Thank you Nick. I gave up on this one. I said "use the next larger fuse". I doubt that a 13 Amp automotive fuse would be available - the next fuse size above 10 Amps is usually 15 Amp. However, since fuses are fuses whatever the voltage I suppose a 13 Amp mains fuse would do if it fits in the fuse box/holder.
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Nic Jarman



Joined: 05 Oct 2008
Posts: 1031
Location: Stoke by Clare, Suffolk

PostPosted: Wed Oct 29, 2008 3:34 pm    Post subject: Reply with quote

Hi Jim, the figures are not supposed to be taken literally but a guide on the relationship between cable size, fuse and current drawn. I was looking back at this thread and solenoids have a short duty cycle so they are not suitable for a semi permanent connection. One would have to use contactors which are rather large and i cannot remember seeing a 6v dc coil on one. If one wants 12v lights etc but wants to keep a 6v starter then use two 6v batteries in series and centre tap the starter. It should be OK to jump this off 12v but I have not tied it. It is usefull to think of a battery as a perfect voltage source with a variable resistor in series, high resistance when flat and low resistance when charged. My friend with a Morris 8 has jumped his car off 12v and has not done any harm to his 6v electrics. It should pull the voltage down to around 9v however I would not leave the two batteries connected for too long.

Nic
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Greeney in France



Joined: 06 Mar 2008
Posts: 1173
Location: Limousin area of France

PostPosted: Wed Oct 29, 2008 4:13 pm    Post subject: Reply with quote

I was speaking to a friend of mine with a traction yesterday, I asked about the 6V thing and he was telling me for the last 20yrs of ownership he has had a 12Vbattery in the boot and has his starter cables going to that, obviously it needs charging once in a while as it doesn't take a charge AND he still has the same 6V starter motor, a 6V anything is made stronger to cope with the higher Amp rating than 12V so generally will cope especially a starter motor. So I think if you could isolate the system enough the odd jump start on 12V wouldn't hurt any
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ukdave2002



Joined: 23 Nov 2007
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Location: South Cheshire

PostPosted: Wed Oct 29, 2008 4:26 pm    Post subject: Reply with quote

I have seen many a 6-12v conversion with the 6v starter motor left on, and they seem to survive, the contol box is a differnt matter and a 6v unit wont like a 12v battery for long.
If you are going to carry a 2nd battery why not carry a 2nd 6V battery round? you could have it charged by the car at all times, use it in parrellel if the main one went flat, and get a 12v jump start off someone else by putting it in series with your main battery?


Dave
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dalbuie



Joined: 24 Dec 2007
Posts: 408
Location: Gullane

PostPosted: Wed Oct 29, 2008 6:05 pm    Post subject: Reply with quote

The starting motor is one of the things that I'm told need not be changed if upgrading the Chevy to 12V. A friend has had several in the past, upped them all to 12V and still has the original starting motors in them.

I'm sticking to 6V though Smile


Last edited by dalbuie on Fri Nov 07, 2008 9:14 pm; edited 1 time in total
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1stpop



Joined: 03 Dec 2007
Posts: 109

PostPosted: Fri Nov 07, 2008 1:08 am    Post subject: Reply with quote

I kept my 6V starter motor without any problems
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Nic Jarman



Joined: 05 Oct 2008
Posts: 1031
Location: Stoke by Clare, Suffolk

PostPosted: Thu Jul 22, 2010 8:21 pm    Post subject: Reply with quote

Nic Jarman wrote:
Hi Jim, the figures are not supposed to be taken literally but a guide on the relationship between cable size, fuse and current drawn. I was looking back at this thread and solenoids have a short duty cycle so they are not suitable for a semi permanent connection. One would have to use contactors which are rather large and i cannot remember seeing a 6v dc coil on one. If one wants 12v lights etc but wants to keep a 6v starter then use two 6v batteries in series and centre tap the starter. It should be OK to jump this off 12v but I have not tied it. It is usefull to think of a battery as a perfect voltage source with a variable resistor in series, high resistance when flat and low resistance when charged. My friend with a Morris 8 has jumped his car off 12v and has not done any harm to his 6v electrics. It should pull the voltage down to around 9v however I would not leave the two batteries connected for too long.
Posted: Wed Oct 29, 2008 2:34 pm Post subject:
The 2 6v batteries in series was discused nearly 2 years ago.
WLC I think 0.5A might be a little bit low. However you could use it as a reference for a nice big trany.


Nic


Appologies to Paul Horowitz and Winfield Hill for the spelling mistake.
All the info is here, when I have rebuilt the Talbot fuel system and then checked through its electrics, and when I have fitted the Morris 8 panels/floor/seats/headliner/rearwings and running boards, then when I have stripped the MGB back to a bare metal shell and rebuilt it, I might just have the time to investigate a suitable voltage regulator, OR use a 2 battery system that I proposed 2 years ago that I thought for some reason was being ignored. Rolling Eyes
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WLC4EVA
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PostPosted: Thu Jul 22, 2010 9:54 pm    Post subject: Reply with quote

Rick wrote:
Can a dynamo formerly used on a 6v system, be converted in order to work in a 12v setup?

ta, R


If you've got a 3 coil regulator Rick, then

!) set the current control to half the original amps
2) set the voltage to twice the original voltage.
3) set the circuit breaker to twice the original volts, plus say 10%.
. . . . . getting the circuit breaker right often involves a bit of trial and error.

You will then get 12v out of a 6v dynamo.

If it's a Jo, Prince of Darkness jobby, it's err, a bit iffy.

Kind Regards, WLC.
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WLC4EVA
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PostPosted: Thu Jul 22, 2010 10:22 pm    Post subject: Reply with quote

Rick wrote:
Thanks ukd Smile

I'm normally an advocate for sticking to original too, I'm thinking practicalities a bit with the big old bus.

With it being quite large, I want to minimise wherever possible, reasons for getting stuck with it somewhere. If I went to 12v, and for instance if I had a flat battery at a show, I could always get a jump start from nearly any other car, or borrow the battery from most other vehicles to get it going. If I'm stuck at the side of the road, kind Mr AA man may be able to give me a jump start too, I doubt he'll have any 6v kit in the back of his van. If I'm on 6v and I have a flat batt at home, I'd not have any other batteries to press into service. Plus if I made a habit of carrying an old car in the back, I could discretely fit a 12v winch, maybe hidden in an old wooden box or similar, rather than rely on the manual winch.

When the Dodge was in use in the 40s, they used to put two 6v batteries together (=12) for starting, then disconnect the 2nd battery once it was running, so even then 6v was perhaps a bit on the marginal side for churning over a 5.4 litre lump. Making a permanent move to 12v now wouldn't be complete heresy, and like you say is a reversible modification.

But for a vehicle with a much smaller engine, like the E83Ws, the Z van or the 10/4, I'd happily stick with 6.

Decision decisions huh! Smile

R

They put two 6vs in series because they were using inadequate 6v batteries Rick.
Batteries cost an arm and a leg in those days, plus 'make do and mend was all the rage.

I don't know what batteries you use, at a guess, they should be long narrow ones.
If I'm right, then you can probably get two in side by side.
Ok, it's not quite original, but a blind man on a charging horse would be pleased to notice the difference.

Civvy Dodges probably used 12v dynamos by the 50s.
If you can get a dynamo off one, it should be a straight swap visually and mechanically.
Ditto the regulator.
It will probably look identical.

After that, run the bits you wish to run on 6v, off the live post of the battery with the earth cable.
And run the bits you want to run on 12v off the live post on the other battery.

If you want to change to 12v ignition, then a 12v relay (solenoid switch) of adequate amperage would pull in the 6v bits.
There are 12 relays that would operate your horn off 6v.

You can, if you wish, operate the starter from 12v in cold weather, and 6v in warm weather.
And you can run your winch, although I suggest you run your engine at a v fast tickover as winches suck the juice, and 12v dynamos don't produce it at low revs.

Kind Regards, WLC
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