Positive ground head lights

[Thomba48]

Embarrassing question, and yes in my next life I shall invest more time in school 

Given that my car is positive ground can I still purchase any sealed beam headlights? Apparently with halogen lamps that is certainly an issue. 

Thanks for your support and inspiration. 

[desoto1939]

I am assuming that you have 6 volt system still in your car.  So you wil lneed to have a 6 volt halogen headlight bulb and not a 12 volt bulb.  It will not matter if positive or negative  for the headlight.

 

Rich HArtung

[Thomba48]

Apology from my end. Yes the original 6 Volt. 

The issue is : I have approached various vendors on ebay. They all stated that their sealed beam offering worked in terms of size and voltage but would not fit a positive ground system. 

Not sure why. Not sure about the logic behind it. 

[DrDoctor]

  Our car is a 6v negative ground, and I installed halogen sealed-beams in is a few years ago. They work great—brighter, with less amperage draw, and the polarity is a non-issue.

[LAKOTA169]

I've purchased regular 6 volt seal beams at a local auto parts store. I've also bought 6 volt halogen bulbs from Rock Auto for half the price the local NAPA store wanted. They worked as well.

[dpollo]

It is only LED lights which need a specific current direction.   Halogen bulbs are just high-end incandescents and are not polarity fussy.

[desoto1939]

You might have to go to an alternator instead of the generator with the halogens but the alt would need to 6v positive ground.  They run around 150 -175 with the mounting bracket.

rich hartung

[Don Coatney]

1 hour ago, desoto1939 said:

You might have to go to an alternator instead of the generator with the halogens but the alt would need to 6v positive ground.  They run around 150 -175 with the mounting bracket.

rich hartung

Why would an alternator be needed? I don't understand?

[greg g]

I would recommend installing a relay to take some of the load off the headlamp switch but watts is watts and though halogens may running a bit hotter than standard sealed beams, their draw is not significantly heavier unless you choose bulbs of higher wattage. I believe standard sealed beams are 35/55 low beam/high beam.  I think standard halogens might be 45/70.  You can get 55/100 bulbs for European style conversions headlamps that are not sealed beam but bulb and reflector style like Hella, Bosche, and Cibie. You might need to rewire to run those but I don't think they are available in 6 volt.

[TodFitch]

FWIW, quartz-halogen bulbs typically put out about 40% more light for the same power as incandescent. As mentioned earlier in this thread, neither quartz-halogen nor incandescent bulbs are polarity sensitive. You could actually power them from AC rather than DC and they'd work just as well.

Recently I came across a link for a fellow in the UK who is making LED replacement bulbs that will fit the original 1930s bulb and reflector headlight sockets. Pricy but I might order a set to see how they work on my '33. The quartz-halogen bulbs I have in there now were picked to be the same wattage as the incandescent bulbs they replaced so that I did not need to worry about overloading the generator or headlight switch. If these LED replacement bulbs pan out then I'd actually be drawing less power from the electrical system than anything that has been run in it including the bulbs from the factory.

Since LED replacements are starting to come out, I thought I'd do a search for ones to replace the old PAR-56 sealed beam headlight bulbs. Nothing came up on my first couple of tries but I bet that it is only a matter of time before someone makes them.

[desoto1939]

19 hours ago, Don Coatney said:

Why would an alternator be needed? I don't understand?

Don:  I have spoken to several vendors that do sell the halogen sealed beam 6v head lights and all have informed me that they recommend the use of the 6v positive ground alternator because of the hologen bulbs.  Theyhave stated that with the draw of the other electrical items the alternator is better suited for the power to runthe headlight instead of the old generator.  i know you might not agree but this is what I have been getting whne inquiring about the conversion to hologen bulbs.

 

rich Hartung

[Thomba48]

rich,

the good and bad thing about owning a classic car. You can do it all and you almost need to know it all. But I don't :-(

I was given the recommendation by many friends of mine to not!!! turn the 6 volt system into a 12 Volt. Done deal. But to exchange the generator with a 6 Volt, positive ground, one-wire alternator. Now that is where my question starts - and my lack of knowledge becomes overly clear - A) If I was to use such an alternator would I actually take the generator out or not ?  do you know of a bolt-in offering from somewhere?

 

thanks from the blind :-)

[Thomba48]

Ok the latter question I have solved myself http://www.qualitypowerauto.com/item_24/6-Volt-Alternators-Positive-Ground.htm. Maybe I can find a "cheaper" offering also.

[Don Coatney]

1 hour ago, desoto1939 said:

Don:  I have spoken to several vendors that do sell the halogen sealed beam 6v head lights and all have informed me that they recommend the use of the 6v positive ground alternator because of the hologen bulbs.  Theyhave stated that with the draw of the other electrical items the alternator is better suited for the power to runthe headlight instead of the old generator.  i know you might not agree but this is what I have been getting whne inquiring about the conversion to hologen bulbs.

 

rich Hartung

Thanks, that is what I did not understand.

[DrDoctor]

   I understand the recommendation for the use of 6v alternator because of the halogen bulbs, if the bulbs are a higher wattage than the originals. If they’re not, as ours are, than I don’t see the necessity of an alternator. I can also understand that the power provided by an alternator may be more consistent than with a generator, especially when factoring in the draw of the other electrical components. But, given all of that, I still don’t see the need for a specific polarity, except when it comes to the original radio, which grounds thru its case, and reversing polarity will fry the radio instantly, rendering it permanently ruined (which is what a previous owner did to ours, so I know of what I speak . . .). So, other than specific scenario, I still don’t recognize, and from what I’m also told by electronics experts, the radio is the only determiner regarding polarity.

[martybose]

The 6 volt halogen bulbs that I ran back in the day were 55W low/60W high, and were definitely beyond the capability of the generator, the headlight switch, and the dimmer switch. I installed a 6V positive ground 60 amp alternator and a dual pole 6V headlight relay.  The idea was to remove the amperage from the headlight switch and the dimmer switch; they only had to switch the relays.  Ran that way for several years until I finally switched to 12V for other reasons.

Marty