I'm going to we wire my shoebox as soon as it gets here and I had planned on switching it to 12v. Is it ok if I just wire it as-is with the positive ground system it has? I have a feeling switching it to the modern neg. ground will take alot more work. I'm also keeping everything stock as far as electrical things go for now.
you could if ya really wanted but take a look at these sites, they may help you when ya do the change over http://www.classictruckshop.com/garage/6to12volts.asp <~~ 6v pos to 12v neg http://www.imperialclub.com/Repair/Electrical/convert.htm <~~ this one is a good one too & it talks about a hint someone else here on the board used to make the change over fairly easy.... hope they help..joe
The short answer is, yes you can. The long answer is, it probably isn't worth the 12V hassle and it isn't really much extra hassle to switch to negative ground at all. The only extra steps required to switch from positive to negative is ammeter/voltmeter, starter button, and any relays (starter/horn/OD) which you'll be changing anyway for the 6V-12V conversion. It isn't really a lot of extra work & then you can run modern equipment off your cigarette lighter....if you go with positive ground, any accessories you run will have to be completely isolated from the car's electrical system.
My dad (who went to college for electrical stuff) told me that a positive ground system and a negative ground system can actually be in the car at the same time. But if you're doing a full 12v conversion, it pretty much has to be negative ground, because I don't think there were any 12v positive ground generators/alternators/starters/etc.
I'm no electrical whizz, but I just picked up a VERY handy little book that talks ALL about conversions and the pros/cons + stuff to look out for. I don't have the book in front of me, but I think all that is necessary to convert is to switch battery cables(change grounding), polarize the 12v generator, install 12V battery, voltage drops behind some of your gauges, switch headlamps & accessory bulbs to 12V, install a 12V regulator & start that bastard. If the 6V wiring is still sound, LEAVE IT. 12V will work with the stock harness very well. Also, don't attempt to polarize an alternator, if that's what you plan to run. I probably missed some stuff, so you may want to invest in the book. It's only like $12 from Speedway or you can probably get it on Amazon. The title is: The Official Guide to 12V Conversion by ?? Rundle(last name) ?? It will take the guesswork out of it if it's your first conversion.
[ QUOTE ] I'm going to we wire my shoebox as soon as it gets here and I had planned on switching it to 12v... I have a feeling switching it to the modern neg. ground will take alot more work. [/ QUOTE ] Why do you think switching to negative ground will be that much more work? It isn't.
If your gonna switch to 12 v.,just go ahead and use neg. ground.It'll make things a lot simpler. Converting my shoebox was the best thing I ever did to it. Before the switch, my greatest fear was that my starter would spin backwards!!!!???? BTW, I've been hitting the original starter with 12 volts for about 12 years now, no problem. Like the others said,your Speedway's catalog has all your answers. Good luck, Glenn
I thought it would be alot more work, because what do I do with all the switches? I'd like to keep the dash knobs it has since they are in great condition and I'm on a tight budget. Also what about the starter? It's the one with the inertial engagement type thing. I have a chrysler style alternator already, but after thinking about it that HAS to be neg ground. Sheesh.... not sure what I am going to do. Ok after thinking about all these replies. I think I need to get my starters polarity switched if that's possible. Is the 226 6cyl starter the same as the 239 v8s?
I think what the guys are saying is that the starter will work. The bendix drive will only engage in one direction and I don't remember hearing about ANY starter problems with this conversion. Six volt wires are usually bigger than twelve volt ones. Something to do with Ohms law: to carry the correct combination of amps/volts the wires have to be bigger for six volts. Starters are not "polarized". There are 12 volt generators available to replace the earlier six volt ones for each manufacturer. There are some custom six volt alternators but think of what you would have to do to get one in the middle of nowhere when yours goes bad. Bottom line: convert to 12 volts, negative ground AND alternator at the same time. Your original switches will work just fine.
Just so we're clear, you DON'T need a new starter solenoid or relay when converting from 6v pos to 12v neg? That's what I always thought, but that classictrucks article says otherwise.
[ QUOTE ] ........ because what do I do with all the switches? I'd like to keep the dash knobs it has since they are in great condition and I'm on a tight budget. [/ QUOTE ] Switches don't know the difference between POS ground or NEG ground. Because they are/were 6 volt, they can handle 12 volts without any problem. (as long as they are in good condition electrically)
Ok well maybe it's a coincidence, but When I first tried to start this car I took everything off the starter solenoid except the starter. I wired in a 12v coil and used a jumper box to try and start it. I didn't realize is was pos. grnd. at the time and hooked it up backwards. all I could get was a whirring noise that sounded like a blower motor, but was just the starter spinning. When I realized it was backwards, the starter engaged and turned it over. Maybe it's just a freaky thing and the starter drive was stuck or something, but this is what got me thinking that the starter wouldn't work with reversed polarity.
[ QUOTE ] Switches don't know the difference between POS ground or NEG ground. Because they are/were 6 volt, they can handle 12 volts without any problem. (as long as they are in good condition electrically) [/ QUOTE ] True for headlight, heater, fan, etc switches, but the way the starter button is wired, it will have to be replaced. The starter button only has one terminal because the housing is the other connection to the dash itself - now ground. If you try to run 12V through it, you WILL short your wiring. The solenoid now requires 12V to the S terminal - can't get there with the stock starter button - no way. You have to replace it with a momentary-on push-button switch that has two terminals on the back & wire it in series with the hot wire to the S terminal on the starter relay. Or you could run a modern key-type switch & not use the original button, but I like the button. Relays & solenoids will work as well - for a while. Then they burn up - too much current running through them. Starters work because they aren't constant use - relays & solenoids are.
cool, well I already got an after market starter button and new ign. switch. I forgot to mention when I tried starting it the first time I just jumpered the solenoid. It is missing the original switch and button. Thanks for all the info guys. I'm gonan go with a 12v neg grnd. Looks like it takes a lot less replacement parts than I thought, plus I already have an alternator for it.
Also, just to dispel a myth, your starter will NEVER run backwards. It's only designed to go one direction. That is why you can convert to 12V and switch the groundings and run the original starter forever. As I said, I really suggest getting this book. Knowledge is power...er something. -Maybe that's why I'm weak. They sell it here & I know Speedway has 'em. http://www.gregsonline.com/eshop/Electrical/LIP612.htm
[ QUOTE ] True for headlight, heater, fan, etc switches, but the way the starter button is wired, it will have to be replaced. The starter button only has one terminal because the housing is the other connection to the dash itself - now ground. If you try to run 12V through it, you WILL short your wiring. The solenoid now requires 12V to the S terminal - can't get there with the stock starter button - no way. You have to replace it with a momentary-on push-button switch that has two terminals on the back & wire it in series with the hot wire to the S terminal on the starter relay. Or you could run a modern key-type switch & not use the original button, but I like the button. [/ QUOTE ] Not nesesarily. If a 12 volt EXTERNALLY GROUNDED starter relay (also refered to as starter solinoid) is used, the stock grounding button can be used. The external grounded solinoids (12 volt) are used in a lot of industrial applications.
[ QUOTE ] If a 12 volt EXTERNALLY GROUNDED starter relay (also refered to as starter solinoid) is used, the stock grounding button can be used. The external grounded solinoids (12 volt) are used in a lot of industrial applications. [/ QUOTE ] OK, I'll concede that point, but not what you'd usually use to replace your firewall mounted starter relay when converting to 12V. Most everyone I know would replace it with a standard Ford, buy-at-any-corner-store starter relay. Only called a starter solenoid if mounted on the starter & used to actuate the starter bendix (think SBC). When mounted separately & only used to complete the high current electrical circuit, it's a starter relay. The Flathead Ford design uses helical splines to engage the bendix. Sorry, one of my pet peeves - they're not technically interchangable terms.
[ QUOTE ] OK, I'll concede that point, but not what you'd usually use to replace your firewall mounted starter relay when converting to 12V. Most everyone I know would replace it with a standard Ford, buy-at-any-corner-store starter relay. [/ QUOTE ] Hummm...I have been stocking them for years. [ QUOTE ] Only called a starter solenoid if mounted on the starter & used to actuate the starter bendix (think SBC). When mounted separately & only used to complete the high current electrical circuit, it's a starter relay. Sorry, one of my pet peeves - they're not technically interchangable terms. [/ QUOTE ] Maybe on your side of the pond; but they ARE over here!
Revhead. Let me know if you need help with the 12V conversion. I have had a 48 Plymouth that was converted, as well as my A. All you need is an alternator with internal regulator (meaning you can get rid of the firewall regulator), some 12V light bulbs, and someone on here had a great idea of hooking a cell phone car cigarette lighter charger up to your fuel gauge since they drop 12V down to 6V. You can get 'em cheap everywhere. Everything else is straight forward.
[ QUOTE ] Maybe on your side of the pond; but they ARE over here! [/ QUOTE ] Dude, I'm a yank, maybe it's because you're in the great white north, eh? You spell like the Brits & pronounce like us yanks (except for the 'ou' sounding like 'oo') I only have the privilege of being here in the UK courtesy of my Uncle Sam (and enjoying it, I might add). Bottom line: You can call it whatever you want, a solenoid & a relay do work similarly, but to be technically & semantically accurate, you should say what you mean. While both work using electromagnetism to actuate, the relay uses it to make a contact (generally without physical motion - only magnetism) & the solenoid physically moves something (valve, starter bendix, door latch, etc.). Most starter solenoids (SBC) use the solenoid to physically move the bendix & physically make the hi-current contact, so it's not a combination solenoid/relay - just a solenoid. [ QUOTE ] Hummm...I have been stocking them for years. [/ QUOTE ] I have no doubt & I'm not trying to enter a urinary olympics here - just pointing out that the standard, off-the-shelf, Ford starter relay that costs about $6.99 is available damn near everywhere. Hell, they probably got them at 7-11! Easier to find than a floating ground starter relay...and easier to hook up (1 wire instead of two). Relax, take a knee, face outward, & drink some water. It'll all be over soon
[ QUOTE ] Bottom line: You can call it whatever you want, a solenoid & a relay do work similarly, but to be technically & semantically accurate, you should say what you mean. [/ QUOTE ] Ernie you ARE right. But after spending 45 years wiring cars, MOST OTHER people don't make the destinction; so I only remind people that the terms are often used interchangably. [ QUOTE ] While both work using electromagnetism to actuate, the relay uses it to make a contact (generally without physical motion - only magnetism).. [/ QUOTE ] Not to start a "p*****g match; but the relays your refering to (NO PHYSICAL MOTION) are common in MANY electronic applications today. But ALL the relays that I stock (high current handling) do rely on electromagneticaly actuated physical movement to make (or break) contact. [ QUOTE ] And the solenoid physically moves something (valve, starter bendix, door latch, etc.). Most starter solenoids (SBC) use the solenoid to physically move the bendix & physically make the hi-current contact, so it's not a combination solenoid/relay - just a solenoid. [/ QUOTE ] Again, your right, but MOST people are not aware of the differences. (I get the impression your are in the electronics business) [ QUOTE ] Hummm...I have been stocking them for years. [/ QUOTE ] I have no doubt & I'm not trying to enter a urinary olympics here - just pointing out that the standard, off-the-shelf, Ford starter relay that costs about $6.99 is available damn near everywhere. Hell, they probably got them at 7-11! Easier to find than a floating ground starter relay...and easier to hook up (1 wire instead of two). [/ QUOTE ] Again NO argument. But the original question of this thread was, "12 volt NEG ground vs POS ground, I was trying to point out that he could keep the original GROUNDING TYPE starter button (because it matched the rest of the switches and dash knobs) by using an external ground starter relay. And they are not that hard to find.
[ QUOTE ] But after spending 45 years wiring cars, MOST OTHER people don't make the destinction; so I only remind people that the terms are often used interchangably. [/ QUOTE ] I know - it's frustrating in some ways. I'm just one of those annoying folks who correct people when they use their, there, they're incorrectly too...my own personal hangup. [ QUOTE ] But ALL the relays that I stock (high current handling) do rely on electromagneticaly actuated physical movement to make (or break) contact. [/ QUOTE ] I obviously don't know what you stock, so I can't say one way or the other. But I've actually taken apart the Ford type several times to repair them because I am a cheap bastard. Most of them only use guides along the coil & not true solenoid operation. Very definitely relay operation (iron core vs "piston"). That's not to say there aren't physical motion switches... [ QUOTE ] I get the impression your are in the electronics business [/ QUOTE ] Nope. My uncle lets me fly his planes. But I did take several industrial electronics courses in HS & my dad owns an avionics shop that I worked at for a few years. [ QUOTE ] I was trying to point out that he could keep the original GROUNDING TYPE starter button (because it matched the rest of the switches and dash knobs) by using an external ground starter relay. And they are not that hard to find. [/ QUOTE ] No argument - you're 100% correct that if he wanted to keep the original style starter button, that's the way to go. I guess I've never seen an externally grounded one (which proves exactly nothing!). It would have to be floating (ie - isolated from the mount) and would require two wires to operate. But it would definely allow the use of the original switch. I guess I take finding the switch for granted with my dad's avionics connection - then I've always used the std Ford relay. w/o the non-verbals, it's easy to take things the wrong way...sorry if I offended.
let me make things simple for anybody that doesn't want to read what dave and ernie are arguing about;GM and Mopar have solenoids,Ford has a relay.
[ QUOTE ] let me make things simple for anybody that doesn't want to read what dave and ernie are arguing about;GM and Mopar have solenoids,Ford has a relay. [/ QUOTE ] Yorg, as about as simple as it can get. Thanks. Ernie, no offence taken. At least between the two of us, (and Yorg) we may have pointed out that there are some differences between the two terms, and that the world of electrical / electronic components CAN be misunderstood. (hope the young guys have taken note of Lesson 101! )
Gents: Is there any way to use a Ford starter button (used on 6V neg. gnd.) on a 12V pos. gnd. system with a starter SOLENOID on a 250 Chevrolet. I am building a '41 Chevrolet of a friend and he wants to have a starter button on the dash. We like the Ford starter button's appearance vs. aftermarket buttons. The Ford button does not have an isolated contact. I guess we can use a relay, but I just wanted to know if I am overlooking something. Alternatively, does anyone know of a good looking starter button with the isolated contact so I can use the hot wire to the solenoid?
My 1966 BSA Thunderbolt motorcycle is still 12V pos ground (for now). Working with it I discovered that most modern "electronics" like Strobe Lights, some LEDs, Stereos, Special Modules, and other modern stuff will NOT work on Positive Ground system. Old electrical stuff - like filament type light bulbs don't care about plus & minus.
Many DC motors WILL run backwards by reversing polarity...like window motors and seat motors. Your Starter Motor is a series wound motor...changing the polarity of the power applied to the starter motor will not reverse the direction of the shaft. You can modify this if you separate the excitation windings and reverse them. DD
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