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CulverDubber Mon Feb 23, 2015 4:16 pm

V-Dub Nation,

I'm the proud, new owner of an all original, 6volt '65 Beetle. And I"m new to the whole VW thing. I've heard two competing theories regarding headlight/interior bulb dimness:

1. If you run 6 volts, you're lights are dim, period.
2. Only if you have 12 volt bulbs on a 6 volt system, will they be dim. (A theory espoused by Chris Vallone of classicvwbugs.com)

WHICH IS IT? I'd like to keep my car 6v but I'd also like my lights a little brighter if possible.

THANKS!

60ragtop Mon Feb 23, 2015 4:23 pm

clean all the contacts, grounds etc and your lights will be fine. they even have a sealed beam halogen light for 6 volts

Bob Loblaw Mon Feb 23, 2015 4:25 pm

12V bulbs on a 6V circuit will be useless dim.
A properly maintained, clean 6V system will provide enough light to see with, but with room for improvement.

bluebus86 Mon Feb 23, 2015 4:27 pm

CulverDubber wrote: V-Dub Nation,

I'm the proud, new owner of an all original, 6volt '65 Beetle. And I"m new to the whole VW thing. I've heard two competing theories regarding headlight/interior bulb dimness:

1. If you run 6 volts, you're lights are dim, period.
2. Only if you have 12 volt bulbs on a 6 volt system, will they be dim. (A theory espoused by Chris Vallone of classicvwbugs.com)

WHICH IS IT? I'd like to keep my car 6v but I'd also like my lights a little brighter if possible.

THANKS!

A 12 volt bulb run on 6 volts would be very very dim if it lights up at all.

the best bet to keep a stock 6 volt system and have bright lights is to repair voltage drops in the switches and connections. corrosion, dirt and loose connections all ad up to voltage drops. a dim bulb (6 volt in a 6 volt system) likely is not receiving the full voltage it requires.

some items like the headlamps can benefit greatly by the addition of relays, which take the load off worn high resistance switches.

go thru the electrical system with a volt meter and measure the drops at each point in each circuit. do a search, there are some procedures on how to do this on the samba, I gave a brief summery of how to do this in a post in the last several months. I am sure others have done a better job describing how to do it. you will need a volt meter and the wire diagram to get you started.

Ps if your headlights are still dim after assuring they are receiving full voltage consider getting new bulbs, headlights and all incandescent bulbs to dim with age, the tungsten filament gets thinner as electrons pass thru it (electromigration), and the tungsten also is evaporated away from the heat. the tungsten that is evaporated away will coat the inside of the bulb, so it is not as clear as when new.

headlight bulbs do get dimmer with age, sometimes you should replace the bulb before it burns out.

First step is to assure you get full voltage to the bulb. :idea: :idea: :idea:

jhoefer Mon Feb 23, 2015 4:31 pm

6V bulb / 12V car = very bright but very quickly burned out bulbs
12V bulb / 6V car = very dim bulbs

25watt/6V bulb in 6V car = same brightness as 25 watt/12V bulb in 12V car
That is, if you have the correct voltage bulbs for the car, if they are the same wattage, they should be equally bright.

What makes a 6V car's light typically dimmer is that a 6V system is affected more by the resistance of corrosion and bad connections.

For example, a 24W/6V bulb will be using 4 amps. A 24W/12V bulb will be using 2 amps. Lets say our wiring is the same between the two cars and has a 0.1 ohm resistance. So that means our 6V car has a voltage drop in the wiring of 0.4 volts, but our 12V car has a voltage drop of 0.2 volts. 0.4 volts is 6.7% of 6V, but 0.2 volts is only 1.7% of 12V. So our 6V car has lost 4 times more voltage for the lights than our 12V car even with identical wiring.

EverettB Mon Feb 23, 2015 6:34 pm

CulverDubber wrote: 1. If you run 6 volts, you're lights are dim, period.

False, most 6v cars just need everything cleaned.

I've had a few low mileage VWs where everything was really nice and the lights were BRIGHT. Brighter than a lot of 12v VWs.

hitest Mon Feb 23, 2015 9:20 pm

jhoefer wrote: What makes a 6V car's light typically dimmer is that a 6V system is affected more by the resistance of corrosion and bad connections.


This, and what Everett said are spot on.

The myths are perpetuated by people who aren't mechanically inclinated or maintenance-oriented owners. They complain about their 6 volt systems without proper care, then they write a check for a 12 volt conversion and all their troubles go away. Three licks to the center of a Tootsie Pop.

That said, there is merit to conversion: clearly, ease of service. It will be a little easier to find a 12 volt choke, battery and HL down the road. Updated radios/accessories as you know are almost always 12v. Thirdly, High performance drivetrains- they all demand 12v. Similarly, you can easily outrun 6v headlights at night at 75mph. Now at 85 in a faster car, I'd rather have a little extra light from a 12 volt bulb set.

CulverDubber Mon Feb 23, 2015 10:13 pm

Thanks for all the info!! It is most appreciated.

morymob Tue Feb 24, 2015 6:38 am

Agree on a total cleanup of gnds,bulb sockert & good batt with a gen/regulator that is chgn c [rrect voltagw WILL do the job very well. Done with bugs & many brand x's. Accessories of12v a pproblem but a stock radio is ok as u approach 50mph u have to turn it off anyway.

Abscate Tue Feb 24, 2015 7:31 am

The brightness of your lights is determined by the Wattage, not the Voltage.

People with dim 6V lights usually have old wires, corroded connections, other malaise rather than an inherently dimmer system.

Helfen Tue Feb 24, 2015 9:48 am

60ragtop wrote: clean all the contacts, grounds etc and your lights will be fine. they even have a sealed beam halogen light for 6 volts

Correct!

and to this;
"What makes a 6V car's light typically dimmer is that a 6V system is affected more by the resistance of corrosion and bad connections."

Corrosion and bad connections do not have a affinity for 6 Volts over 12 Volts. Corrosion and bad connections happen equally and will plague both systems, even airplanes have the same trouble with 24 Volt systems.

jhoefer Wed Feb 25, 2015 11:27 am

Helfen wrote: 60ragtop wrote: clean all the contacts, grounds etc and your lights will be fine. they even have a sealed beam halogen light for 6 volts

Correct!

and to this;
"What makes a 6V car's light typically dimmer is that a 6V system is affected more by the resistance of corrosion and bad connections."

Corrosion and bad connections do not have a affinity for 6 Volts over 12 Volts. Corrosion and bad connections happen equally and will plague both systems, even airplanes have the same trouble with 24 Volt systems.

Read the example I gave for why what I said was true. Yes they are all affected, but equal corrosion does not have an equal effect on 6, 12, and 24 volt systems.

Gary Haberman Wed Feb 25, 2015 3:59 pm

I took the advice of all these very experienced people on this site and my 6v '62 T1 has very adequate standard headlights. I replaced the headlights themselves as well as the connectors, installed additional 12g ground wires, replaced the headlight switch and all the terminals on the fuse block associated with lighting. Also replaced both the battery terminals (and transmission ground jumper). It also pays to clean up the headlamp glass and repaint the headlight buckets, replace the tail light sockets also and the blinker relay. Be proud of your stock car!

Ajvdub Wed Feb 25, 2015 4:11 pm

My 64 is still 6 volt and the lights are dim compared to my daily driver (Chevy Volt).

Keep the 6V as long as you can, they are hard to find.

drscope Wed Feb 25, 2015 6:50 pm

Ajvdub wrote: My 64 is still 6 volt and the lights are dim compared to my daily driver (Chevy Volt).

Keep the 6V as long as you can, they are hard to find.

6 volt VW to chevy volt.....That ain't comparing apples to apples!

6 volt Vw to 12 volt VW, that's comparing apples to apples.

6 volt system needs to be clean and everything needs to be in good shape. If it is, the lights are just as bright as the 12 volt stuff.

The real issue is that the 12 volt system seldom needs cleaning and it stays bright even when things get neglected and ratty. But if things get a little ratty in a 6 volt system, they don't work as well.

tasb Wed Feb 25, 2015 7:04 pm

This is my all original unrestored December of 1955 beetle. It has the original wiring still in place. The headlights and tail lights are just fine especially after cleaning the ground contacts. My original 1960 beetle has new wiring and I have gone through the grounds and the tail lights are still very dim.


rockerarm Wed Feb 25, 2015 7:56 pm

First off welcome to the scene here. Much to learn and share, as you are already experiencing.
I think you will be happy with an original 6v car, as long as you recognize a few of the issues. The lights will be a bit dimmer. Also, some replacement parts are getting harder to find. (But that is even occurring with the 12v cars now!) There is also a smaller voltage range before issues occur. On a 6v system the minimum voltage where components begin to not function is 4.8v. That is only 1.2v. On a similarly equipped 12v car the minimum is 9.6v, a 2.4v difference. This is not a big deal on perfect cars but who has one? I fully believe any and all issues can be mitigated with due diligence. Do you expect to daily drive this car? Just curious.
I tend to like the E-code H4 headlights and 6v bulbs are available for you here. Nice.
If you intend to work on your car yourself and want anything then let me know. I can even show you how to perform the voltage drop tests that I and others suggest.
Hope this helps, Bill.

61SNRF Wed Feb 25, 2015 8:26 pm

jhoefer wrote:
For example, a 24W/6V bulb will be using 4 amps. A 24W/12V bulb will be using 2 amps. Lets say our wiring is the same between the two cars and has a 0.1 ohm resistance. So that means our 6V car has a voltage drop in the wiring of 0.4 volts, but our 12V car has a voltage drop of 0.2 volts. 0.4 volts is 6.7% of 6V, but 0.2 volts is only 1.7% of 12V. So our 6V car has lost 4 times more voltage for the lights than our 12V car even with identical wiring.

Excellent example of using Ohm's Law http://en.wikipedia.org/wiki/Ohm%27s_law to illustrate for anyone to see why 6 volt is more sensitive to high resistance than 12 volt, well said j :D

I often like to use the Drain Pipe theory http://en.wikipedia.org/wiki/Hydraulic_analogy to get the basic idea of DC electrical energy storage and transport across to laymen. If you can understand this, then you know that 6 volt simply has half the electrical pressure to push past the same obstructions or restrictions that 12 volt has.

And while true in theory electricity never breaks down, every car is different on how it "conducts" itself :lol:

As in tasb's best case example, took a nice original '55 out of long term storage last year, and after fixing a few minor loose ends at the tail lights, cleaning their connections and replacing the bulbs, I was shocked that the lights were so bright! They were as bright as any 12v Beetle I've ever seen :D

The '66 I currently call mine? Cleaned all connections externally and the head lights are still dim. A jumper wire connected from B+ to low and high beam fuse box terminals brightens them up some, but not 100%. This tells me the head light switch has some internal resistance which simply means refurbish or replace.
But what about the remaining voltage drop/resistance? My experience say's that while the '61 and later push-on style connectors are easier to use and more convenient than screw type, the mechanical connection where they are crimped on to the bare copper wire can corrode, and in old age develop excessive resistance.
They are quite impractical to clean using simple abrasive methods to their exterior surfaces, so an etching chemical dip treatment and a good re-crimp of them where they meet the wire may help, or perhaps an entire harness replacement in worst case.

Helfen Wed Feb 25, 2015 8:44 pm

"I often like to use the Drain Pipe theory http://en.wikipedia.org/wiki/Hydraulic_analogy to get the basic idea of DC electrical energy storage and transport across to laymen. If you can understand this, then you know that 6 volt simply has half the electrical pressure to push past the same obstructions or restrictions that 12 volt has."

This would be true if a 6 volt car had the same drain pipe as a 12 volt car. A 6 volt car's electrical system has a bigger drain pipe, or in car terms, the wires are bigger to handle the restrictions and obstructions.

jhoefer Thu Feb 26, 2015 12:09 pm

Helfen wrote: This would be true if a 6 volt car had the same drain pipe as a 12 volt car. A 6 volt car's electrical system has a bigger drain pipe, or in car terms, the wires are bigger to handle the restrictions and obstructions.

Yes, in general a 6V system needs to handle twice the current, But check the wiring diagrams on this site. The wire gauge for the headlights, battery to fusebox, and others didn't change from 1954 to 1974.



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