pierpaolo Posted January 12, 2004 Share Posted January 12, 2004 I have just discovered from the shop manual that my 1955 chrysler windsor was originally ground positive (6v). What had to be changed at the time it was converted to ground negative?? How can I check that everything has been done properly? What could be the reason for the conversion, is there any advantage or disadvantage? And what should I do to return it to the original condition? Sorry about all this question, but I has been really a big surprise for me!Thanks, Piero Link to comment Share on other sites More sharing options...
48LCCOUPE Posted January 12, 2004 Share Posted January 12, 2004 What was it converted to? 12V neg or 6V neg? Link to comment Share on other sites More sharing options...
pierpaolo Posted January 12, 2004 Author Share Posted January 12, 2004 6V negative Link to comment Share on other sites More sharing options...
Guest Skyking Posted January 12, 2004 Share Posted January 12, 2004 My Metropolitan was positive ground and I switched it over to neg. ground. These are the instructions I used for the Met. It should work the same for you. Switch the wires at the coil. Turn your battery around and connect positive cable to positive post on the battery. Connect the negative cable to the ground. Get a wire long enough to stretch from the battery positive to the engine compartment. Have someone hold one end of the wire (with end of wire exposed) to the positive post on the battery. The 2nd person take the other end of the wire (wire exposed) and brush it against the "F" (field) post on the voltage regulator until you see a few sparks. You are now converted. Check all your fuses to see if any blew out, and if you had gauges, you will need to reverse the wires or the display will be backwards. I don't know about the gauges, I didn't have any.......hope this helps! Link to comment Share on other sites More sharing options...
pierpaolo Posted January 12, 2004 Author Share Posted January 12, 2004 What about generator, voltage regulator, starter motor, solenoid, etc., no change to be done to any electrical component? doesn't make any difference? Link to comment Share on other sites More sharing options...
Guest JT Posted January 12, 2004 Share Posted January 12, 2004 Probably someone along the way installed the battery backwards. I don't know of any reason to change from 6 volt positive ground to 6 volt negative ground. I would connect it as original and polarize the generator. Link to comment Share on other sites More sharing options...
Guest Skyking Posted January 12, 2004 Share Posted January 12, 2004 Some cars did come from the factory with positive ground. Metopolitans were one of those cars. I changed mine so I could add a tape deck & other accessories w/o a hassle....... As far as generator, starter and voltage reg., they didn't have to be touched. Link to comment Share on other sites More sharing options...
52deluxe Posted January 12, 2004 Share Posted January 12, 2004 actually the guages should still work, my 52 packard had been coverted to negative ground. i have sence converted it back, you will need to polerise "i know its spelled wrong" your generator "short the a and f term i think" make sure your regulator will work with positive ground. you do need to switch the wires on the coil but it will run if you dont. i think i read somewhere that there were problems with corosion due to the positive ground setup, but i cant remember for sure.tom Link to comment Share on other sites More sharing options...
48LCCOUPE Posted January 13, 2004 Share Posted January 13, 2004 <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">What about generator, voltage regulator, starter motor, solenoid, etc., no change to be done to any electrical component? doesn't make any difference? </div></div>These items don't really care (except the voltage regulator polarizing the gen).When the starter switch is engaged for example, it simply completes the circuit, a loop if you will, the loop doesn't care who completed it, the neg or the pos. Link to comment Share on other sites More sharing options...
48LCCOUPE Posted January 13, 2004 Share Posted January 13, 2004 I was just thinking, if you have an amp guage, you will have to reverse the wires on the back or it will go in the wrong direction. Not to sure how your gas guage will like the switch, that is if it works now. Link to comment Share on other sites More sharing options...
Guest Skyking Posted January 13, 2004 Share Posted January 13, 2004 the amp gauge may be a problem, but the gas gauge will work fine. Link to comment Share on other sites More sharing options...
Guest JT Posted January 13, 2004 Share Posted January 13, 2004 tom, in theory the positive ground will have less corrosion than the negative ground. I think that's at least part of the reason the British stuck with positive ground for so long (the Brits switched to 12 volts earlier than the US but kept the positive ground for many years). I just wish US manufactures had switched to 12 volts sooner than they did, it would make adding on that cd player a lot easier. In the case of my 40 Packard (6 volt) they put 12 volt systems on the exported models only. Link to comment Share on other sites More sharing options...
Guest DeSoto Frank Posted January 13, 2004 Share Posted January 13, 2004 "Less corrosion" where?(Unless you're speaking specifically about the battery terminals, my posi-ground MoPars rust just as fast as anything else... )Unless this '55 Chrysler is an Imperial (12v positive ground), it should be 6-volt positive ground. From '56 on, all MoPars are conventional 12vNeg ground.The only gauge that will "care" about polarity is the ammeter, and it will simply read "backwards"; it won't be damaged. The temp gauge (if not vapor/pressure) and fuel gauge are both bi-metal resistance gauges and aren't polarity sensitve. The oil pressure gauge is mechanical.As stated in the foregoing posts, the generator will need to be polarized to match what ever polarity you're going with. If you have a MoToR's of Chilton's manual covering your year, follow the steps there for proper polarization proceedure.The only reason I can think of for changing polarity without going to 12 volts would be some matter of convenience (couldn't get the right battery cable or voltage regulator...?), or somebody wanted to use accesories that were 6-volt neg ground only. Link to comment Share on other sites More sharing options...
52deluxe Posted January 13, 2004 Share Posted January 13, 2004 i know the fealing about 12 conversion, im about this close [ ] to converting the car to 12v. mostly so it will start easier. it starts easy when its cold, but i did a overhaul a while back and when the engine is hot it still has trouble turning over "its getting better slowly" also i would like to be able to run 12v lights as they are brighter and easier to get "i think you can get 12v halogen round headlights now." im not to worried about music as i just found a nos aftermarket motorola radio that was made for 51-52 packards "lots of chrome" but it would be nice to have FM cause i live in the middle of nowhere and get only 1 AM station unless i drive to buffalo about 60 miles away. if i do convert im going to use a 12v generator or find a 12 alternator that looks similar to the current set up. but this is down the road as i am going to replace the waterdistribution tube, timing chain, timing gears, and valves this year. "i hope"tom Link to comment Share on other sites More sharing options...
Guest Albert Posted January 14, 2004 Share Posted January 14, 2004 52 deluxe, I flipped my 54 over to neg ground, then i can run a 12v converter and a regular 12v radio/cd or you can get a fm converter that plays through the AM radio. my 54 i have started at -20c last winter without a problem, it just takes a lot of fiddling with the little things, and i am also using 2/0 welders cable to the battery. and you can get 12V 7 inch helia that will fit nicely in the front of the Packard. the only reason i was thinking of 12v was i would like AC in mine at some point later. Link to comment Share on other sites More sharing options...
52deluxe Posted January 14, 2004 Share Posted January 14, 2004 i thought about using a converter, jc whitney sells a 6v positive ground to 12 negative ground converter for about 40.00. but i have heard these make a buzzing noise. the biggest down side i see to a converter is when you run a accesory that draws 12v and say 300 watts "decent stereo" your 6 volt generator has to produce 600 watts to compensate. plus i would like to run HLED's in the brake lights and markers for added visablity. then running a stepdown transformer for the radio would be very simple, i think you can still buy 12v to 6v converters at radio shack. as for the starting, the hard start now only occurs when the engine is at full operating temp. the engine will turn over much slower then when its cold, it will fire right up when its cold out but i usually run the starter for a few seconds to get a little oil pumped up. i half suspect that there is a high resistance short in the starter causing a marked decrease in torque. i has never failed to start and in the last year it seems to have gotten better, so maybe things are starting to wear in a little bit. it just depends how much time and money i can put into the car without the wife getting to mad, so rarely gets to see more then a pair of feet sticking out from under the car. tom Link to comment Share on other sites More sharing options...
Guest stude8 Posted January 14, 2004 Share Posted January 14, 2004 For 52deluxe, slow cranking is usually related to undersized cables, deteriorated cables (strands rotted / corroded especially at terminal crimps) or under rated battery. There are strong and weak capacity 6v batteries, find a good agricultural supplier with heavy duty tractor batteries to fit your application.A comment on the polarity changes, they can have a bad effect on distributor ignition point contacts, the fixed and moving points were often dissimilar materials designed to not transfer material when used with the polarity the car was designed with. If you experience ignition problems or rapid transfer of point metal (one builds up a hill, the other gets a pit) you will know why.Stude8 Link to comment Share on other sites More sharing options...
pierpaolo Posted January 14, 2004 Author Share Posted January 14, 2004 Thanks all for the information, things are much more clear now.At this point, the question is: should I switch it back to positive ground? I mean, is it worth doing it or not?The only pros/cons I can see are that with pos ground I could restore the radio and use it as it was originally, while the corrosion would be faster (according to my informations, anodic corrosion happens on metals with positive charge).In case I decide to reverse the polarity, what is the correct procedure to polarise generator and voltage regulator?And what about the coil? As 52deluxe says, should I invert the wires? How can I check which is the right way (if it hasn't been done the first time)?Regarding the gauges, the fuel one works fine, the temp one is stuck in "cold" (but i to know how to check if is the gauge or the sender unit) while the amps and oil pressure ones are always at middle scale (they seem to work but never moves once started the engine): can anyone suggest me a way to check if the last two work? Link to comment Share on other sites More sharing options...
52deluxe Posted January 14, 2004 Share Posted January 14, 2004 most coils will have a + or a - on the contacts. just remember that the wire going to your points is ground. so if you want the car to be postive ground make sure the + is going to the distibutor, switch it if you want neg ground. now converting a radio is veeeery easy, just install the proper vibrator for the ground you are using antique radio supply sells them in 12v and 6v both + and - ground. plus you have the added reliablility of a solid state vibrator. as to weather you should switch back, its personal preferance i dont see any advantage either way. stude8 i know the wires are plenty big enough and they are new, but the battery now that you mention it is pretty small. i originally bought this one with the intent of getting a larger one when i decided the car was worth it, but the only farm supply store near here closed its doors. i did have a larger one for a while but it would not sit in the battery tray "had to turn it sideways" so i gave it back. i also did not know about the points being directional, so i did learn something promise. Link to comment Share on other sites More sharing options...
Guest stude8 Posted January 14, 2004 Share Posted January 14, 2004 For 52deluxe:One other snag I forgot about, early batteries (even up to 1950's) had draft to their case walls, that is they were narrower at bottom than top because of the way the rubber cases were molded. Thus a modern straight wall battery case of the correct capacity probably won't fit the battery box correctly. I had to make a new straight wall battery box for my 1930 Studebaker (under the floor boards, nobody could see it) to fit the heavy duty #2 6v lift truck battery it wanted (336 CID inline 8 cyl). Stude8 Link to comment Share on other sites More sharing options...
Peter J.Heizmann Posted January 14, 2004 Share Posted January 14, 2004 piero...are you out there?Folks are putting quite a bit of time into assisting you.Any input, more questions, opinions?Regards, Peter J. Link to comment Share on other sites More sharing options...
pierpaolo Posted January 15, 2004 Author Share Posted January 15, 2004 Hi Peter,I am here and ready!I have already posted my comments, further questions (obviously, my curiosity is neverending!) and thanked everibody for the help just 2 posts above yours.The reason why sometimes I don't aswer immediately is that I live in England, so there is a consistent time difference (I am near to wake up when you are surfing the web!)By the way, at the moment I am working on the ammeter, that is steady in the middle position, i don't know if is the ammeter or the voltage regulator not working. Any suggestion how to check if the ammeter and the regulator are working properly?Thanks again to everibody,Pierpaolo Link to comment Share on other sites More sharing options...
Guest Albert Posted January 15, 2004 Share Posted January 15, 2004 You can check with a volt meter across the battery when it's running you should get around 13.8V-14v for a 12v batterys and 6.9V-7.2V on a 6V battery, the amp meter should swing to the - side (discharge) if you turn the headlights on without the motor running as well, quite often you will notice the turn signals will also cause the amp meter needle to twitch to the - side too. Link to comment Share on other sites More sharing options...
pierpaolo Posted January 15, 2004 Author Share Posted January 15, 2004 Albert,I think this way to check the ammeter won't work on my car because only the current to the battery goes through the meter, all the load for other uses (lights,etc) bypasses it. Link to comment Share on other sites More sharing options...
Guest imported_MikeWilliamsUK Posted January 15, 2004 Share Posted January 15, 2004 Piero,Just a note to say you are not alone. I also live in England and am filing all this correspondence away as I'm converting my 1938 Lincoln from 6volt pos to 12volt neg, a process started by the previous owner nearly 50 years ago, so he obviously thought it worthwhile to get better lights. Probably Slightly easier on an older car as less electrical bits and bobs.Mike Link to comment Share on other sites More sharing options...
Guest Albert Posted January 15, 2004 Share Posted January 15, 2004 The one side of the ampmeter should be the only connected to the + side of the battery (assuming - Ground)(other than the large dia wire connected to the starter), the other side of the ampmeter commects to the rest of the car's electrical system, this way it measures all the current entering or leaving the battery,(charge or discharge) at this point the cars headlights, ignition, and Generator/alternator are connected. Switching from 6V to 12V should not be any problems with the wireing as long as the wire is in good condition (no missing insulation or bad connectors) as 6V wiring is a heaver guage than 12V. the only thing is to replace or adapt all the 6V parts to 12V, about the only thing you don't have to replace it the starter and the horns. For + Gnd to -Gnd, resetting the generator, flipping the ign coil around is about the only thing you have to do and if you have an amp meter reverse the wires on the back (also check the radio + electronic devices), the starter will still turn in the right direction as it is field wound, the only motor you may run into a problem is some fan motors have perm. magnets in the fields, these will change direction, but if you open the motor you can reverse the wires connected to the brushes and reverse the direction to what you want. Link to comment Share on other sites More sharing options...
pierpaolo Posted January 16, 2004 Author Share Posted January 16, 2004 Albert,this morning I have switched on all the lights and the heater fans with engine at idle and the indicator moved to 2/3 on the discharge side.This means that the ammeter works! This should also mean that the wires were inverted correctly at the time of the first swap (+G to -G).I've done it also driving (about 15-20mph), and the same thingh appens for few second, is it normal?This evening I will test the battery voltage with engine running at higher speed to check the regulator, and probably this weekend I will revert the car to the original, mainly to be able to reinstall the original radio once repaired. I have been told that inverting the radio polarity is not very easy, is it true? If i will have problems I will ask.Pierpaolo Link to comment Share on other sites More sharing options...
52deluxe Posted January 16, 2004 Share Posted January 16, 2004 a real quick test to see if its charging, just let it idle with the front of the car against a building "so you can see the lights" and rev the engine, if the lights get brighter your charging. its quick, easy, and you dont have to pop the hood. im lazy like that.tom Link to comment Share on other sites More sharing options...
pierpaolo Posted January 20, 2004 Author Share Posted January 20, 2004 Well, I am back!I have few more question: there are two small electrical components that I haven't still identified, both are located betweeen the battery and the regulator, one is rectangular (approx 3/4"x1") with four contacts, 2 large and 2 small diameter wires connected; the other is a black cilinder (approx 1"dia x 1.5") again with 4 contacts, 2 large and 2 small dia. wires.My guess are starter relay, and the other don't know!!! Maybe horn relay or neutral safety switch (I can start the car with any speed selected, so I don't know if I don't have it or if it is not working).The other question is: is it normal for the Voltage regulator to become hot when the engine is running? If not , what could be the cause?Thanks,Pierpaolo Link to comment Share on other sites More sharing options...
Guest DeSoto Frank Posted January 20, 2004 Share Posted January 20, 2004 Piero,The smallish rectangular box is probably the horn relay. The other larger unit may be the starter relay. (Am trying to recollect what is under the hood of my '55 De Soto)Yes, it is normal for the voltage regulator to get "warm" after 15-20 minutes operation...,ore important is to check the wiring going to it...none of the wire should get too hot to hold your hands on it. Any signs of smoke or smells of scorching indicate trouble. Link to comment Share on other sites More sharing options...
Mrbuick714 Posted January 24, 2004 Share Posted January 24, 2004 I am no expert on Mopar,in fact there are those who may think I am not an expert on anything,but here goes.On GM products,the points on the regulator are made of dissimilar metals,this to minimize.metal transfer.Reversing the polarity causes much transfer and premature failure.Another thing to consider is the radio.It may not work with the wrong polarity. I am not very daring,I usually put things back to standard. Link to comment Share on other sites More sharing options...
gearboy Posted January 24, 2004 Share Posted January 24, 2004 Regardless which way you go, Jim Irwin at Antique Auto Battery, Hudson, Ohio 1 (800) 426-7580 can supply reasonably-priced 6-volt positive- or negative-ground alternators, as well as Pos.- or Neg.-ground 8- and 12-volt alternators. Simple bolt-in installation with NO butchering of your car or wiring harness. Your old generator can be bolted back in quickly should you sell your car to a purist. Jim was a big help when i called him about a 6-volt alternator for my '47 Packard Su-8 last week. We really need to support businesses that bother to help the old car crowd, otherwise there'll be nothing left but a retro/repro kar industry. Please tell him Mike referred you. Tho' this website is [color:\\"black\\"] for Classic cars 1925-48, i wish you luck, since Chryslers were the best American cars of the '50s, in my 'umble opine. [color:\\"black\\"] [color:\\"black\\"] Link to comment Share on other sites More sharing options...
Mrbuick714 Posted January 31, 2004 Share Posted January 31, 2004 We have a guy in Norfolk,Nebraska who would agree with you. Link to comment Share on other sites More sharing options...
mackensen Posted July 10, 2017 Share Posted July 10, 2017 NAPA will have the bat. you need Link to comment Share on other sites More sharing options...
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