VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 1954 Bel Air question heater 6 volt to 12 volt

Hi,

I just purchased a 1954 Bel Air and drove it home over 120 miles. This thing runs great! Straight as an arrow down the road and drove beautifully.
It was converted to 12 volt before I purchased it.

Everything works, all gauges, etc, but the heater blower motor does not.

In the control unit, where the wire cables go that control heat, defrost, etc, there is a switch with connectors for 2 wires.
Upon inspection I see that the wire going to the blower motor is connected from the switch to the blower motor.
But there is also another wire that is just dangling there and not connected to anything.

1) Is that wire for a power supply?
2) Now that the car has been converted to 12 volt I am afraid that the blower motor will burn out because it was designed for a 6 volt car. Any ideas for a power supply?
3) What should that power supply voltage be?
4) The power supply and switch to blower motor are cloth wires. Can cloth wires handle 12 volts Or do they need to be changed out?
5) The black switch (button) on the control unit, there is a screwdriver pointing to it in the photo- should that touch the metal stop when the lever is pushed as far as it should go because mine does not?????

Thanks so much for the help!

The blower motor should have two wires; one is a ground, the other is the power source. If the motor spins backwards, simply reverse the wires.
Not familiar with the switch you mentioned, and your picture did not load. My experience after 60 yrs of old Chevys and hot rods, is that the
the old 6v wire handled 12v just fine. Most 12v wire today is 14ga., and the old cloth wires were closer to 12ga. I tapped off the hot (on) terminal of the ignition swith on my '54 truck.

On the blower motor, if you need to change it over to 12v., contact O'Reilly for a replacement. It is the same motor that other suppliers sell
for 2 or 3 times as much. i posted the info. on the '54 Chevy forum, about 2 months ago. If you can't locate it, just reply here.

Bob

Thank you. I had some time today and hooked the blower (still installed in the car) up to 12v for just a second, and it came on. I did exactly what you mentioned above......I tapped off the hot (on) terminal of the ignition switch for power. I am running that wire to a 15 amp fuse and then to a 12v to 6 v reducer and then connecting it to the switch. I still have a 6 volt motor and don't want to mess with changing it out. What do you think of that order in the wiring. Wasn't sure if I should put the fuse before or after the reducer....or if it doesn't matter either way.
Thanks.

I would do it just like you did. Better to have the higher amp portion fuse-protected to be safest. That way any spikes will not cause
a problem. Glad you got it working! Bob

Feel the voltage reducer for heat and locate it accordingly. The rule is that the extra 6V energy canny be made to "go away" it can only be converted to another type of energy (heat)

Should I attach it to an isolated area behind the dash? An area where nothing (wires) etc, can make contact with it? And tucked away high enough so any passenger will not touch it. I am sure that thing will get pretty hot.

Does it only heat up when the blower motor is turned on?

should only heat when current flowing through so yes...only heats when on. Just keep it away from anything that it's heat might damage. Probably has some sort of aluminum heat sink built into it also. Just wanted you to be aware of it's heat and plan accordingly.

OK. Thanks.

Make sure the resistor is not burnt out. It looks like a stretched out coil spring, Usuall on or near the switch.

Thank you.

Can I run the radio and blower motor off of one 12 volt to volt reducer?

Not recommended.

I received my 12 volt to 6 volt reducer in the mail today. It is a small gold colored reducer with a contact on each side,

When I hook it up to 12 volts on one end, I am getting 12 volts on the other end. I tried swapping out the wires and the same thing. Shouldn't I be able to wire it to my 12 volt key on ignition and get 6 volts out to the other end to hook to my blower motor?

If the blower motor is positive ground, is there some additional wiring I need to do? When I hook it up to 12 volts it comes right on. I only run it for a second at 12 volts.

I am sure I am missing something. Any thoughts?

No wiring instructions? What brand? Pictures?

Without knowing how the reducer actually works it is not possible for us to be able to knowledgeably reply. If it is just a resister then it will take some level of current flow to measure a voltage difference. V = I x R.

I have no experience with one of these things, but do know something about general electrical stuff including resistors.
A resistor can't lower voltage until there is a current flowing. With no current you will still have 12 volts on the output side.
As soon as current flows and is being held back by the resistor, output voltage drops.
As it is current (amps) that burns things out, static voltage is irrelevant, and only current flow really matters.

As always, I may be wrong.

https://www.ebay.com/itm/12-Volt-to-6-Volt-Voltage-Reducer-Heater-Blower-Motor-Voltage-Reducer-6V-wiper/171695758294?hash=item27f9dd5bd6:g:WV4AAOSwQJhUjOWk

Above is a link to the reducer. I can not post photos.

I thought that if I hooked it up to 12 volts it would measure 6 on the other end without any current. Learned something new today!

There were no wiring directions so i assume I can connect 12 volt to either lead?

What size fuse would you recommend before the reducer, 12 volt 30 amp?

What you have is a common resistor rated at high wattage. You may connect the power source (12-volt) to either end and the load (heater, light ect) to the other end. You will measure 12-volt at either end until the power is applied to the resistor. You will get a flash of 12-volts initially and it will slowly reduce to approximately 6-volts based on the load. Since you are dealing with 12-volts you can use a 10-amp fuse for example.

A reducing resistor is a very poor system to operate 6-volt items on a 12-volt system. This is because of the initial flash of 12-volts to the load.

A proper system is a device that produces a controlled voltage drop. This system is readily available, but is expensive.

What happened to the idea of operating the car on the original 6-volts, they used it without problems for many years?

Well, it is connected but I am only getting .87 volts out of the other end of the reducer, so the motor will not come on. If I jump the 12 volt wire over to the other terminal of the reducer, the fan will come on.

I have tried 2 different power sources; The ignition switched on and a straight 12 volt power. I have done this without the car running but the ignition switched on.

Any ideas what might be going on??????

OK, I just thought of something. I am running a new wire with a lead after the reducer to the blower switch. However, I am using wire that I use for most of my 12 volt electric projects. I am thinking that I am using the wrong gage wire. It is 12 volt at the reducer and it is less than 1 volt at the end of the wire that comes from the reducer.
I will try that tomorrow.

Was the wire from the reducer connected to the motor when you had the 1 volt reading? If it was not then you had very little current flowing through the resistor/reducer.

I doubt if the size of the wire is an issue for a short term test.

Have you tested the blower motor with a 6 volt battery?

I think you re going to have better results in the long run by converting to a 12 volt motor. Or spend the money for a step-down transformer or converter. The limitation is that if the motor requires 10 amps at 6 volts to operate properly you have to dissipate that same energy (60 watts) in the resistor.

The reducer is 4 ohms and I think the blower is 1 ohm. I think that is my problem. Thanks.