The 12-volt Conversion Guide is a well-laid-out, professionally typeset, 28-page booklet containing a wealth of information on the topic, well written and thoroughly explained by an obviously experienced technician, one Randy Rundle. I've never spoken to Randy, but intend to give him a call now that I have excellent materials in hand. One item he manufactures is a six-volt alternator that has many collector-car applications, with brackets to fit about anything. He has been involved in several Great Race vehicle electrical systems through the years. The book's introduction is accurate. Quote: "This book is a no-nonsense guide to upgrading your automotive electrical system from 6 volt to 12 volt. Most of us have no desire to become electrical engineers; we just want to know what we have to do to make everything work." I can't imagine this not being interesting reading and reference material for just about anyone in our hobby; he covers many vintage car electrical topics and conversion requirements. Randy's address, etc: Randy Rundle Fifth Avenue Antique Auto Parts 415 Court Street Clay Center KS 67432 ==================================== You'll need new motors for the wiper, heater & defroster probably. I replaced mine but some guys use volta-drop boxes. 12v coil & battery, of course, and replace all the bulbs with their 12v equivalents. If your car has an overdrive, it's okay as is and generally the horn will survive more juice. Get a one-wire alternator from a local auto electric place and they'll show you how to hook it up. Easy-squeezy! --------- I think those dual voltage batteries are cool.. Has two positive terminals on it. One 6v, and one 12V... Some rewiring to get it all to work, but a neat setup. The starter will handle 12 volts just fine... Jeff --------- Another option is a Conversion Aid that dorps the voltage for the instrument panel and accessories. Units can draw up to 20 amp and then you can use a 12 volt battery and let the starter take the 12 volts but everything else can be 6 volts and it a cheaper way. . . cost $20 - $30 depending on apllication and can be purchase from Hot Rod and Custom Supply in Cape Coral, Florida. ---------- I knew I forgot something...if you have a radio, you'll have to either send it to someone who's adept at conversions from neg. to positive grounds and 6-to-12v, or use a voltage dropper. ================================================= Sep 20-04 Generally, if you are having problems, slow starter, dim lights then you likely have a corroded ground or wiring problem (sometimes completely hidden inside the covering), and it is time to replace/restore anyway. Changing to 12V just masks a bad problem which isn't going away. Changing to 12V without addressing problems with deteriorating wiring is just doubling your chances of having electrical fires when you double your voltage. You are better off cleaning grounds etc with a wire brush/sandpaper/whatever, using dielectric paste to ensure good contacts, and checking out every wire/circuit for impedance to find the culprits. remember your wiring is OVER 50 YEARS OLD! If you just want a more trouble-free output and longer battery life, you can simply get a 6Volt alternator. Positive ground ones are available (via the Model T crowd especially)...but if you want A/C, that is still a problem. If your 49 doesn't have too many "modern" stuff options contemplated, it gets a lot simpler. Perhaps I might suggest what a local fellow does. Change to 12V alternator/battery, and 12 volts to starter, keep absolutely everything else 6 volt. Wire in step-down(s) to everything else: lights/dash/lighter/ignition/gauges/flasher/ etc to keep them at 6volt, its simpler. Keep the generator for someone else. It should not harm your starter to run on 12V for the next umpteen years if it was in good shape in the first place, and it will turn much faster. Other than radios, it makes little difference to many things whether the alternator is positive or negative ground, as such. If you want modern A/C and high power stereo, do what he does and wire in a direct 12V circuit to those items only. Using solenoids instead of old mechanical switches is a very smart idea--especially if you succumb to the lure of high-powered headlights. If you want to run something new on 12Volt, especially halogen headlights, it needs new wiring too. Likely the best possible solution is to replace old 6V wiring with new 6V wiring, and use it also for the 12V items too (double the size=less crowding of electrons ) Jim Bartley on PEI ===== Send $10.00 to: Randy Rundle Fifth Avenue Antique Auto parts 415 Court Street Clay Center KS 67432 and request a copy of his book, "The Official 12-Volt Conversion Guide." It is excellent. He also sells the various resistors and any alternative parts you will need. BP ------ Feb 2005 Here's what I did on my '53 hardtop. The gauges are not polarity sensitive. I built a little 12V to 6.5V linear regulator and mounted it to the back of the cluster to run the temp and gas. The radio was a bigger problem. I am a EE and reconditioned a cosmetically nice '53 8 tube radio (the one with pushbuttons) I found at a swap. The tube radios are not polarity sensitive, as long as the mechanical vibrator tube is still being used. However, the solid state (electronic) replacement ones available now ARE polarity sensitive. I had can-openered the original vib tube and sanded the points to get it working at all for my repair/testing work and it worked fine with either polarity. For permanence, I put in a 6v neg ground SS vibrator tube and then built a switching power supply to provide the 6.5v neg ground power for the radio. My radio takes about 7-1/2 A at 6.5V. The 6 tube (non push button) radio probably takes a little less. The SAMs service manual says they both take 5A or so, think there is a error there.... Except for the electronic vib tube, the rest of the radio is still vintage tech. Another alternative is it is possible to convert the radio itself to 12v power. The 6v tubes can be swapped out for 12v ones. Thats the easy part. The problem is the power transformer. That needs to be changed to one with a 12v primary winding. There are places that will do this sort of conversion. There are also places that you send your tube radio and they gut it out, replacing the insides with digital tuning and modern electronics. Somehow they are able to keep the outside looking stock and the tuning knob and buttons still work. That service when I checked was in the $250+ range. I'm thinking about doing it with a spare parts radio I have since AM radio has a pretty poor choice of programming. I found a NOS aftermarket FM converter box that I use now but it drifts around a lot on stations. Its a cheapo kraco or something from the 70s. Those convert the FM to AM and feed it to the AM radio through the antenna. Jeff H ================================== READ THIS!!! //////// A quick check of the starter showed the teeth all tore up. My //question is : Would a 12 volt starter turn over a six volt flywheel for a //few dozen starts before talking a crap. I'm not sure where the flywheel came //from, but it sure does not like the starter and I wondered if I had the //teeth count wrong. /////// ------ The 12 volts have 162 teeth and the 6 133. This is for the V 8 cars. ------ correct me if im wrong,but i was told there is a difference between a 6volt and a 12 volt starter. the 6 volt starter has the same number of teeth as a 12 volt,but the actual gear is larger in diameter than a 12 volt.the 12 volt starter wll work on a 6 cyl flywheel,but not for long.the teeth dont have sufficent depth penetration into the flywheel teeth and will strip off the very edges of the drive gear on the starter.something to consider when doing a mix and match. --- --- It looks like it might be a six volt flywheel, it did strip the teeth off the drive. ------ the 9 years in the starter shop hammered home ONE FACT.. IF you got a 6 volt vehicle, AND convert it to 12.. you CAN leave the starter ALONE IF you do NOT have to sit and crank on it a LONG time.. it will then, fry.. eventually.. BUT, if the engine starts good, then you are fine. ---------- if you have the six volt starter and a six volt flywheel (133 teeth) with a 12 volt system, it should work fine. The starter will last as long as you don't grind on it several seconds at a time. I used this set up on the CH for years with no problem and the six volt starter spun it so good, it would almost start before you got off the starter. Ted ------------------------