6 Volt headlight wiring

E

El Rat

Senior Member
Hi gents...
Over the weekend I was checking the voltage at my headlights. Suprise suprise I had 5.6 volts (not running) at the end of the cowl wiring to the headlight and 4.5 at the bulb (through the Bob Drake kit). It is easy to see why when you compare the quality of construction and the wire diameter. Regardless I ordered headlight wires from Tyree Harris and am searching for NOS bulb holders to solder to.
Note: not a slam on Bob Drake just commentary. Probably less of a problem on 12V.
 
I have Drake halogen headlights in my '47. They were less bright than the regular sealed beams, so I installed an alternator. The lights were about the same, maybe even less bright. The switch contacts were good, the dimmer switch was new but the loss was in the original wiring and connectors. I designed and built a relay board which is controlled by the original wiring, but feeds the headlights full battery voltage. Now, my headlights are almost as bright as the newer vehicles. If anyone wants the free "how to", let me know.
 
Believe this is the setup superreal uses (or very similar). In his design he uses starter solenoids. The second photo is of mine which uses different solenoids and is connected up differently, but the same basic idea. If you are using 6v starter solenoids connect it up like superreal's diagram.
 

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I have a 6 volt system similar to what Supereal has on his. You would not believe how bright your lights will be.
 
Relays together with new wiring was a great improvement for my headlight and fog light systems. I obtained my kits from MAD Enterprises of CA (see web site). Available in 6 and 12 volt, relays kits including with wiring and connectors. Suitable for most any higher-current drawing device (lights, radiator fans, etc). Installation directions provided and can talk directly to the technician if desired.
 
Once again, I caution everyone, if your staying with a 6V system (especially) the 6V wire is bigger for a reason. 6V systems produce Twice the AMPS as a 12V system and that is where MOST everyone who complains about 6V systems is having problems. AMPS are the issue!!! Too small of a wire on a 6V system, or 12V wire CANNOT handle the AMPS thus the wire will get hot and COULD eventually cause bigger problems ESPECIALLY the longer the length of wire or the longer the AMPS have to travel. Traditionally your headlights are the 2nd furthest from the power source and generally travel through two circuits and several junctions (ie connectors), thus the drop in both volts and more importantly AMPS. Once again volts are not the issue, it's the AMP's that make everything work. sort of like the relationship between horsepower and torque, when you step on the accelerator, you don't feel horsepower in the seat of your pants, you feel torque!!!! Its the ability to handle the AMPS!!!!!!
 
Just thinking out loud here,
Do you need two chuffing great starter solenoids for this? Wouldn't normal 6volt headlight relays do the same thing?
Are those starter solenoids ok for the prolonged use of the lights being on?
Just seems a bit like cracking an egg with a back hoe to me.
like I said, just idley thinking out loud.
Martin.
 
scooder said:
Just thinking out loud here,
Do you need two chuffing great starter solenoids for this? Wouldn't normal 6volt headlight relays do the same thing?
Are those starter solenoids ok for the prolonged use of the lights being on?
Just seems a bit like cracking an egg with a back hoe to me.
like I said, just idley thinking out loud.
Martin.
Click to expand...

Do you need ... starter solenoids for this: NO
Would normal 6v relays do the same thing: YES
Are starter solenoids ok for prolonged...: superreal and several other that use them says they are, mine are continuous use solenoids. The headlight load is so far below the starter solenoid design loads that it is not an issue.

The starter solenoids ARE overkill, it is just a simple solution to a solenoid source. 6v solenoids are harder to find, but are available. Don't think anyone is claiming the start solenoid setup is the idea solution, it is just a solution that I for one think is a cool use of existing parts.
 
I used starter solenoids to devise my headlight relay panel. Finding 6 volt relays that can handle a couple of hundred watts continuously can be a problem. I used NAPA (Echlin) solenoids, ST541. They will work fine used for long periods of time, and the price is a fraction of industrial units. I also use those solenoids as relays in my convertible top control for the same reasons. Unless you have rewired your car, and replaced the switch, dimmer, and "bullet" connectors, the loss in the system eats much of the power to the headlights. This is known as "I-R drop' Ohm's Law says voltage is the product of current (amps) times resistance (ohms). When I taught this stuff, I used the water analogy. If you have a hose that is too small, but good water pressure, the flow (quantity) will be reduced at the nozzle. Trying to force current thru "leaky" wiring is the same situation.
 
Thanks for the answers. Didn't realize that 6volt relays are harder to get hold of over there. Fairly easy to get over here.
I do absolutely agree it's a cool use of parts, I like stuff like that.
Martin.
 
scooder said:
Thanks for the answers. Didn't realize that 6volt relays are harder to get hold of over there. Fairly easy to get over here.
I do absolutely agree it's a cool use of parts, I like stuff like that.
Martin.
Click to expand...

Hasn't been much 6v stuff around sense the late 50s to early 60s and relays are not a normal rebuild part for U.S. cars. The VWs and some other imports had them. They are around, just have to look a little harder. In my case, I didn't like the looks of the square relays that much, could of hide them, but liked to looks of the larger relays. The ones I use are HD continue use relays, not starter relays, but they look the same.
 
Here is a very good source for 6 volt relays. I just got one and it is fine:

Newark element 14 newark.com

Here is a portion of my invoice:

Shipment:

Line No:
1 Stock No: Mftr. Part No:
UOM:
Qty Invoiced: Price:
Extended Price:

30M9197
DG85B-8011-96-1006-M1
Each 1
1
$4.76
$4.76
Customer Part Number:
Description: AUTOMOTIVE RELAY, SPDT, 6VDC, 60A; Coil Voltage VAC Nom:-; Coil Voltage VDC Nom:6V; Contact Current Max:60A; Contact Voltage DC Nom:30V; Coil Resistance:22ohm; Contact Configuration:SPDT; Relay Mounting:Quick Connect; No. of Poles:1
Your Merchandise Total $4.76
Sale in USD
If you have questions regarding your current order please email us anytime. Or you can contact our Customer Service Team at: 1-800-463-9275.

Our Terms and Conditions of Sale apply and are available here.

We look forward to serving you again soon,
 
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