6v to 12v Conversion for Dummies

Ed:



I got my wiring harness from Rhode Island Wiring. In fact my '50C8 is what they used for the 1950 patterns. I am assuming you have a 6 cylinder so the engine harness is not the same but some of the other harnesses may fit. The best thing to do is send your harness in and they will make an exact copy from it, with the correct wire color codes and a map for you when it returns.



I have been surprised that starting up with 6V is not as bad as some had said it would be. It really works pretty well. I think having a good battery and good wiring with a good ground are all that is necessary. Also, I am going to put in a headlight relay with 6V halogen headlights which should make up for the sealed beam dimness.

Pacemaker500 wrote:

Really only for better starting and brighter lights for safety. Any tips on boosting starting power?



The wiring is solid but the original coverings are showing thier 56 years of age. I would still like to put in new OEM-loke alike replacement wire.



Thank you for your suggestion.

You need big high capacity cables from the battery to the starter, a good earth from the engine to the frame and a starter motor that is fully effective.



My cars are 6v and no problems at all, wouldn't even consider converting to 12v. They start in a heavy frost no problems, or even after sitting for a month and having to crank long enough to fill the carb float chamber. The ET8 has big bright lights, very strong for 6v..........whereas you often hear that one reaosn to go 12v is for better lights.

Reproduction wiring, if you buy from a reputable company will come labeled and with a wiring map. It really is not very difficult. If you take yours out carefully and do not hack it up they will be able to make an exact repro. I would label where each one came from. Mine came back with all the wires tagged and labled so it was a snap to put the new one in. I only replaced my front wiring, not the interior lighting or rear lights since the front was the only area that had been mouse eaten and a lot of age wear.



Here is a source for 6v Halogen headlights, I got a dual headlight 6V relay on ebay! If you do this upgrade I would suggest you get 12 guage wire between the relay and headlight cross over, 12 guage for the cross over and 12 guage for the headlight buckets. Run a 10 guage from the battery to the power lug on the relay. You will need to tell the wiring vendor that is what you want for the cross over and bucket wires since they are usually 14 guage.



http://www.danielsternlighting.com/tech/relays/relays.html

My '49 Commodore Six has a Optima battery, six volt battery cables and a headlight relay. The car starts like a 12 volt car and the lights are as bright as a 12 volt system. See this thread for a happy user of a Optima battery and six volt battery cables.



http://www.classiccar.com/forums/showthread.php?t=5245&highlight=optima

Well I would have to disagree here to an extent and respectfully. True in good condition a 6v system will do the job as my Hornet WAS 6v and it did OK and my 51 Ford F-1 is still 6v and it works perfectly BUT was is your long term plan for your car? What sparked me to convert was the generator crapped out at the Western regionals and several suggested I convert over to a single wire GM alternator. I pondered the thought for a few weeks and decided 6v stuff is not readily available like 12v ie bulbs,batteries. Also if you want to add things to the car like I have with my Pertronix ignition and soon will have electric wipers, maybe you want A/C, then the 12v is the way to go. It wasn't that hard to convert. Park W wrote a pretty good instruction sheet on how to do it. I deviated from it a little, but not much. I spent most of my time patching up the crumbling wiring than doing the conversion. Later I learned a company called Y&Z here in CA have full wiring harnesses for less than what I am sure I spent on my labor time, piecing,heatshrinking,soldering,sectioning my old wiring. Had to make a mounting bracket for the alternator, but some off the shelf Chevy stuff at the local speed shop got me close, and I did some minor welding, grinding and painting to make it really look like factory. I am very pleased with it now and now can do pretty much anything I want with it now because it is 12v powered. Just my 2 cents and I plan to drive it a lot and I don't want to be out in the middle of nowhere and need 6v stuff.

I picked up an (new) Echlin 6V dual headlight relay (NAPA part # HR-300) off of ebay for $7. They are also available at your local NAPA store as well. These should be much less than $29 ea. which I find way out of line for a single 6V relay. If you get a headlight relay, as opposed to just a 6V relay they usually have fuses inside so you don't need to put then in the circuit yourself.