Electrical: 12-volt to 6-volt resistors

[dstude]

Has anyone had any experience with the Runtz 12-v to 6-v voltage reducers sold by Speedway, or Speedway's voltage reducers for motors? The Runta stuff sounds good. Any problems with them?

Generally, what are people using and recommending for voltage drop devices these days--for gauges, heater/wiper motors, radios? Last time I did this I used a Volta-Drop and it worked great. Thanks.

[StudeRich]

Studebaker Parts are just SO interchangeable from one year to another, that most have no problem eliminating MOST of those "Problems" by just using the Studebaker 12 Volt equivalent Parts for the Model involved.

The only thing that does not interchange from 6 to 12 Volts and Look Correct, are the Temp. Gauge and the Fuel Gauge, so you do not need serious Amps Load pulling out of a Volt-A-Drop in 6 Volts.

This eliminates all that Load on your Battery and Generator to "burn" up the AMPs.

[brngarage]

Don, I have been using the Runtzes I got from Fifth Avenue (in Kansas) for 5 years for my fuel and temp gauges in my '53 Commander and they work great.

[Mike Van Veghten]

Very common.
Been sold under many brand names, been sold for many, many years.

You might check into the solid state designs. They produce a lot less heat.

Mike

[gordr]

The only voltage drop devices that are suitable for gauges are the solid-state voltage regulators, like those Runtz. Regulators are active devices that sense the output voltage, and automatically compensate for changes. Resistors really are not voltage reducers; they are current reducers, wired in series with a load to reduce the current through the load to what it would be if a six-volt source were used. The kicker is that many of the loads that we might wish to reduce the voltage on are not purely resistive, and don't follow the simple expression of Ohm's Law. Motors and solenoids being good examples of that. The overdrive solenoid being the poster girl for not playing nice with dropping resistors.

[dstude]

So, the amp gauge and the oil pressure gauge do not require the use of a current reducer/voltage regulator, is that correct? Does the sending unit for the oil pressure gauge need to be changed?

And what is the best way to deal with the heater motors, a pair of the current reducers I see marketed specifically for electric motors? Or are there better 12-volt motors that will bolt-in, perhaps motors that turn a little faster? Thanks.

[gordr]

The ammeter will read accurately on either six or twelve volts. It is not voltage sensitive. Now, the range may be inappropriate for the new system voltage, but it will work, and most of us just use it as a yes/no check on charging, anyway. Studebaker oil pressure gauges are normally direct-reading, and have no sending unit. Oil pressure is carried to the gauge by a very slender tube. The "senders" for oil pressure lights are just switches, and don't care about the voltage applied. But the bulbs will need to be replaced.

If you do have an electric oil pressure gauge, it would need its own Runtz voltage regulator, same as the fuel and temp gauges.

[dstude]

Concerning the voltage reduction device sold by Speedway and others (a 3" long, gold-colored heat sink with a wire terminal at each end), would one, located at the switch, be enough for the Climatizer's two fan motors? Speedway says it will work with "up to 10 amps of continuous draw."

[gordr]

Concerning the voltage reduction device sold by Speedway and others (a 3" long, gold-colored heat sink with a wire terminal at each end), would one, located at the switch, be enough for the Climatizer's two fan motors? Speedway says it will work with "up to 10 amps of continuous draw."

Well it might not burn up, but it won't drop the voltage you expect it to do. All that thing is, is a wire-wound ceramic resistor encased in an extruded aluminum heat sink. For heater and defroster fans, that logical thing to do is to use an open wire coil as a resistor, and mount it in the air stream so the heat it dissipates is put to some use. Car manufacturers used to put their speed control resistors in the air plenum for that very reason. But it's also pretty easy to swap out out Studebaker fan motors with 12 volt motors from a later Studebaker, or even Brand X permanent-magnet motors you can get for a couple of bucks each at Pick and Pull.

[bensherb]

it's also pretty easy to swap out out Studebaker fan motors with 12 volt motors from a later Studebaker, or even Brand X permanent-magnet motors you can get for a couple of bucks each at Pick and Pull.

That's true, I used a fan motor from a '75 Ford pickup to replace the 6 volt one in one of my '54 Chevy's, and the wiper motor from it too replacing the vacuum one in the Chevy.