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Update 6 volt to 12 volt on my 1940 special


Mun24ster
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I am currently switching my 40 Buick to 12 volts. I have removed the generator and put in an alternator with a self contained voltage regulator, thus eliminating the car's original. I put in the required ignition coil. Also replaced the starter solenoid. Of course replaced the battery to a 12 volt. Made all the wiring changes according to the info sent to me by vintage auto garage, where I purchased the kit. My 40 Buick method of starting the vehicle has been switched to a push button start. Now is where I am stuck. When I push the button, I am getting a clicking sound as if its trying to send power thru, but nothing is turning over on the engine. Am I missing a wire to some place, sounds electrical problem to me, but I don't have a clue. Any help would greatly be appreciated.

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Sounds like the solenoid is not working or the starter is cooked. It could also be the starter button, the wiring, the ignition switch, or the battery. I would guess the solenoid is bad since it's the cheapest part. Start there.

 

Sadly, you're pretty far down the conversion road and diagnostics are going to be a lot more difficult. Is there a specific reason you're converting to 12 volts? It complicates things considerably when things don't work because it doubles the number of things that could go wrong. Instead of making things easier, it often makes things more challenging when trying to maintain a vintage car.

 

Anyway, if power is going to the solenoid, your battery is fully charged and load tested, and the wiring is good, then somehow it's not kicking power to the starter. That's the solenoid's job, and it doesn't sound like it's getting done.

 

I would also wager that if you put all the 6V parts back in, it would start...

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Go over the electrical diagram.     The electrical system is very simple.     The only thing that most people miss is the grounding circuit that goes thru the regulator.   The solenoid has only two wires.   One goes to ground (thru the regulator) and the other gets its power from the starter button circuit.    Use the original 6 volt starter and solenoid.    They work fine.     Wiring size is more than sufficient when going to 12 volts.        Get the newer 12 volt head lights that are about  35 /55 watts.      The original were  I believe  25 / 25 watts.    I just had my '35' 50 series head lights recoated by a guy in Michigan.  ( Vacuum Orna-Metal ,  Frank @ 800-827-6762 ).     They look like mirrors.    I am converted to halogen bulbs.   Details if wanted.   

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the simplest answer is the battery posts. 

 

Check the connection of the heavy "hot" cable on the solenoid terminal.

Also check the heavy copper strap  connections from the other solenoid terminal to the starter case.

All of the starter current...which is a lot of amps...has to go thru

the solenoid so these connections really have to be good

 

Is the battery voltage at 12V or so  ?

 

I suggest these in the vein of "easy things first"

 

I suppose you still are using the original battery cables ( for 6V service )...these 

are plenty heavy enough  for 12V use

 

Jack Worstell

Edited by Jack Worstell
Clarification (see edit history)
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Yep, sounds like the "Kit" did not know the Buick wiring. The two ways to fix this, 1. go back to 6 volts and motor on. 2. Complain to  vintage auto garage that their kit did not replace the Buick wiring properly and now the solenoid does not pull in. Get them to understand it is their error. Have fun!🤣

 

See Jim's explanation above to the error.

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When I did mine,  I used Rhode Island Wire.   They sell partials such as 'Dash to engine' wiring.       My 35-57  and my '38-46s' wiring needed help.    Their kits are well documented,  labeled and easy ( ?) to  understand and install.    Is your wiring is decent shape ?      Both My '38'  and '35' needed help 'safety wise'.     One thing in the conversion is '12 volt systems are common'.   for those who are not electrical talented.      Jay at Vintage is a fair guy but I suspect he bought a system that someone put together for resale.     Converting to 12 volts is fairly easy.    All lighting bulbs are replaced with 12 volt bulbs.   You did the correct upgrades to the  ignition coil to 12 v.    The original  6 volt starter / solenoid assembly works nicely on 12 volts.   BTW,   removing  the regulator removed the built-in ground for the starting circuit.    That system was designed to use a coil in the regulator to keep the car from trying to start again after the engine is running by disconnecting that part of the start  circuit.      One of the two wires going to the starter solenoid goes to the regulator..    by running that wire a good engine ground will fix  - eliminate that factory  generator safety circuit as you use the much better alternator.   The other wire leaving the solenoid goes to the vacuum start circuit.   I really hope you installed a 3 wire alternator.   The single wire alt does not put out until you get going.      Google '3 wire alternators' for a good education on them.    By wiring a normally open push button across the original vacuum start circuit - by passing it so it cannot work,    that lets you start the engine ONLY when you push the button.    Now if you have a solenoid issue - that is a starter / generator repair shop fix.    They have the instrumentation to check out and repair problems.      Study your Buick provided service manual  (you have one right  ? )  and they have a pretty good electrical diagram.    Remember,   their diagram is electrical circuits and a "not as actually wired" diagram..  electrically wired per the service manual when chasing problems but  - well, get your buddy to explain just how.   You will become a good fixer of their fairly simple designed electrical ...     much is duplicated year to year with minor improvements for increased complexity. 

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Yes,   I forgot that you must use a 'Runtz'  voltage controller for the gas gage.    You will cause failure it not used.     There are some others but  Runtz is the best.     You don't want to replace the sending unit or have the gas gage repaired. - - -,     

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Well,  there is one other item that needs modification.    The heater is wired for 6 volts but you can get a wire wound voltage reducer to keep things kosher.    You can get  some mid 50's heater blower motors that are 12 volts.     I think I have covered everything  - - I  hope,   I think its 'old timers disease' creeping up on me - - -  ya man.......

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Oh, and the clock.

 

And the radio.

 

And the ammeter.

 

And the horn relay.

 

And the defroster motor.

 

And the turn signal relay.

 

All that stuff is already in the car. Why is 12 volts better, again?

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Fix it till it’s broke............1940 Buick’s have driven millions of miles.......the 6 volt set up from new was definitely no good.

 

To be fair to the original poster, most people have no clue why they are doing this, thinking the car will be better. It will not. Just like the electric fuel pump that is most certainly wired incorrectly, and unsafe. Par for the course. David Dunbar Buick is rolling over in his unmarked grave.

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Doing an extensive restoration on my bucket of junk and decided to convert to 12 volt.  

Probably should have given six volt a chance since everything will be new.

Seems everything I remember about 6 volt meant dim lights and slow engine cranking,  but as long as it didn't take too much to get it started maybe I should have just lived with the dim lights.

 

I like how some people make sarcastic comments about the phrase " upgraded to 12 volt "!

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I converted my 1940 Special to 12V because I couldn't find a "check engine" light that was 6V. And when I wired the doors to make a dinging sound when they were ajar, they were all 12V. I put seat belts in the car, but the seat belt warning light I installed was too dim on 6V and was hard to see, I was afraid I wouldn't see it and forget to put my seatbelt on. This could lead to death, so I converted the car to 12V for safety reasons.

 

NOT!!

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Yes, but you found it hard to get a 6 volt fuel injection system!😄

 

 

On 5/30/2020 at 1:07 AM, 1937McBuick said:

 

I like how some people make sarcastic comments about the phrase " upgraded to 12 volt "!

 

Because if only changing the system from 6 to 12 volts, with no other accessory modifications, it is a waste of time and energy, not an upgrade.

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On 5/30/2020 at 12:07 AM, 1937McBuick said:

Doing an extensive restoration on my bucket of junk and decided to convert to 12 volt.  

Probably should have given six volt a chance since everything will be new.

Seems everything I remember about 6 volt meant dim lights and slow engine cranking,  but as long as it didn't take too much to get it started maybe I should have just lived with the dim lights.

 

I like how some people make sarcastic comments about the phrase " upgraded to 12 volt "!

 

 Just have to consider the source.  I HAVE NEVER BEEN SORRY I changed to 12V.  Ten years and almost 20,000 miles. Replaced the 12V battery after 9 years.

 

  That's my story and I'm sticking to it.

 

  Ben

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7 minutes ago, Morgan Wright said:

I don't see why you didn't just upgrade to 120V AC and get a Maytag.


Best laugh I had In days.👍

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I'm kinda new here and have the mentality of "live and let live".

I made a choice and am going to live with it.

This car will be very well restored and I'd like it to be close to original,  it won't be competeing in any car shows that matter!

I am fussy and more money is being spent on this car than makes sense,  but I'm not doing it to make money on it....I'm fulfilling my 30 plus year old dream.  I want to drive this car,  enjoy it,  and take care of it.  

 

To each his own....

 

Let's help each other and respect each other's opinions at the same time.

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20 hours ago, 1937McBuick said:

I'm kinda new here and have the mentality of "live and let live".

I made a choice and am going to live with it.

This car will be very well restored and I'd like it to be close to original,  it won't be competing in any car shows that matter!

I am fussy and more money is being spent on this car than makes sense,  but I'm not doing it to make money on it....I'm fulfilling my 30 plus year old dream.  I want to drive this car,  enjoy it,  and take care of it.  

 

To each his own....

 

Let's help each other and respect each other's opinions at the same time.

 

I also in the driving category,  but I have lot older cars.  Over all, I strive to be the same as from the factory, except for safety items.  Some of those items include replacing the wood in the wheels with new wood, upgrading the wheel bearings from ball bearings to tapered bearings, and adding stop light, etc.

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I almost always recommend staying with the original electrical system in a car. Now that's not due to my purist point of view, because I agree that driving is the point and whatever gets you on the road is OK with me. I say it simply because few 12-volt conversions actually make sense. Most guys assume that 6-volt systems are inferior and there's a persistent myth that old cars were always hard to start and that changed when 12-volt systems were introduced. Not true, but I bet if you ask 10 guys at any local cruise night about 6-volt electrical systems, you will get 10 guys telling you that they're crap. So part one of the problem is this myth that 6 volts doesn't work. That's BS, but persistent myths in this hobby are not a new thing.

 

Now that I've had, oh, 3500 cars pass through my hands, I have come to realize that trying to out-smart the factory engineers is a dicey proposition. At best you get something that works, but it is merely one guy's idea of how it should work. If it works, that's fine. But if it doesn't work or needs replacement parts, it can be extremely difficult to diagnose the problem and figure out what parts that one guy in his home garage used to do his work. Repairs become significantly more difficult at that point because the factory shop manual, with its detailed diagnostic procedures, is completely worthless. Now you've got to figure it out for yourself without the assistance of the really smart guys who built the thing in the first place. You're pretty much stuck with us yahoos on the internet shooting darts in the dark.
 

I know I've mentioned the 1946 Mercury convertible I had where the previous owner had converted it to 12 volts. It worked fine except the entire car was wired using red 12-gauge wire. EVERYTHING. Should something go wrong with that car, how the heck do you fix it? It worked, but it was a recipe for nightmares for future owners and had a significant impact on the car's marketability and value. Nobody wanted to touch that thing, even though it was ostensibly operational.

 

The conversion can be done without a lot of difficulty, but it's never as easy as it seems and it never really solves any problems without adding a bunch of new ones. Everything electrical in the car will stop working and will need to be altered somehow. Most guys don't bother making the original gauges work and just slap some Summit Racing gauges under the dash and call it done. They figure they only drive in the summer so they don't need the heater or defroster fans to work. Clocks never work anyway, so they skip that, too. They wire up a modern stereo system in the glove box and cut holes in the doors or side panels for speakers or remove the original radio and chop up the dash to make a new one fit. I guess that's all fine and dandy for a car you're going to just drive, but it always screams amateur workmanship and laziness and ultimately the car probably doesn't drive any differently. And the next guy is going to look at your workmanship and strt discounting the car immediately.

 

What most folks don't seem to realize is that most of the problems people have with 6-volt electrical systems can be fixed with cheap, easy repairs: good battery cables, clean grounds, strong battery, rebuilt starter, healthy ignition components. I find that more often than not, a 12-volt conversion is used as a band-aid for sub-standard electrical components throughout the car and the guy doing the work figures it's junk rather than solving the actual problem. There's that myth again.

 

So while I'm not necessarily a purist, I am practical. I am of the opinion that making the original equipment work properly is not only better for values, but also for serviceability and functionality, and simple repairs will typically cost less than a 12-volt "conversion." You can change and upgrade and alter all the parts that need to be changed and upgraded for 12 volts, or you can simply use what's already there and save time and money without taking any steps backwards in terms of service or functionality.

 

 

Edited by Matt Harwood (see edit history)
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Matt,  as you can see from the pic of my resurrected "find", where it was resting peacefully until I found it......I am basically starting from scratch.   So I decided to make it twelve volt,  I don't think I ever used the word "upgraded", but may have used the term "converted".

 

 

IMG_20190409_220458_891.jpg

 

Maybe the most frustrating thing will be there is no ground wires to alot of things,  relying on a ground path through body panels etc might be interesting given this thing was in pieces,  current has to flow regardless of 6 or 12 volts.

Edited by 1937McBuick (see edit history)
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I suspect a lot of the negative comments around 6v is because there are so few well sorted systems out there, my Cadillac’s 6v system is all originally and will fire instantly (as long as the timing/throttle/enricher is correctly set) easily as well as a modern car. Our 26 Buick is a different proposition in that it can be slow to start, but that’s got nothing to do with electrics and all to do with the bowl on the carb running dry and it having to build a vacuum to suck in fresh fuel - if you didn’t know what’s going on you’d probably assume it’s slow cranking because that’s what you have to do if you want to get fuel into the carb without manually topping up the gravity tank.

 

Lighting is also similar in that it’s rare to see 6v systems that the silvering is still in good condition or has been done properly, when in new condition they actually quite reflective with no globe even in them

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When I did mine,  I used Rhode Island Wire.   They sell partials such as 'Dash to engine' wiring.       My 35-57  and my '38-46s' wiring needed help.    Their kits are well documented,  labeled and easy ( ?) to  understand and install.    Is your wiring is decent shape ?      Both My '38'  and '35' needed help 'safety wise'.     One thing in the conversion is '12 volt systems are common'.   for those who are not electrical talented.      Jay at Vintage is a fair guy but I suspect he bought a system that someone put together for resale.     Converting to 12 volts is fairly easy.    All lighting bulbs are replaced with 12 volt bulbs.   You did the correct upgrades to the  ignition coil to 12 v.    The original  6 volt starter / solenoid assembly works nicely on 12 volts.   BTW,   removing  the regulator removed the built-in ground for the starting circuit.    That system was designed to use a coil in the regulator to keep the car from trying to start again after the engine is running by disconnecting that part of the start  circuit.      One of the two wires going to the starter solenoid goes to the regulator..    by running that wire a good engine ground will fix  - eliminate that factory  generator safety circuit as you use the much better alternator.   The other wire leaving the solenoid goes to the vacuum start circuit.   I really hope you installed a 3 wire alternator.   The single wire alt does not put out until you get going.      Google '3 wire alternators' for a good education on them.    By wiring a normally open push button across the original vacuum start circuit - by passing it so it cannot work,    that lets you start the engine ONLY when you push the button.    Now if you have a solenoid issue - that is a starter / generator repair shop fix.    They have the instrumentation to check out and repair problems.      Study your Buick provided service manual  (you have one right  ? )  and they have a pretty good electrical diagram.    Remember,   their diagram is electrical circuits and a "not as actually wired" diagram..  electrically wired per the service manual when chasing problems but  - well, get your buddy to explain just how.   You will become a good fixer of their fairly simple designed electrical ...     much is duplicated year to year with minor improvements for increased complexity. 

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Over the last 50 years, I have solved MANY "carburetor" problems, as well as hard starting ignition problems, on both 6v and 12v systems. The solution: first scrape off the 92 coats of engine paint that the "restorer" placed on one of the head bolts; then connect a heavy-duty jumper cable from the ground terminal of the battery to this particular head bolt. Paint is not a particularly efficient carrier of electric current.

 

Jon.

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