Heater fan speed ?

aussie merc

aussie merc

Well-known member
does anyone have any idea how fast the heater fan should spin on high [car was converted to 12 volt but no idea about any bolt ons [found radio had been converted to 12v but wired back into 6v when reassembled ] so it remains to work out the rest figured that rpm would be the easiest to work it out Doesn't seem to move a lot of air on 6v
 
12-volt motors for heater/defroster generally have smaller gauge wire windings than 6-volt types. There are multi-speed motors that have several field windings for the different speeds. Unless an electric motor is series wound then it will be polarity sensitive as to the direction the motor turns. This can affect function if a person changes to negative ground.

It helps to know what type of heater and the year model of the vehicle.
 
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What it boils down to is that you have to install a 6 volt motor to have it run at the original design speed.
12 volt motor will run slower on 6volts,
 
I got a 12v computer fan for my car heater. It works great and doesnt draw a lot of current. They come in many different diameters as well. And did I forget to mention that they are CHEAP and hide behind the heater core so nobody can see it
 
Dilstro1950 ????????????? the motor spins in either direction thats how it runs heat or defrost the reversing is done thru the switch just want to work out if it should be 12 or 6v
 
It seems to me that you should run it on 12v to see if you like the fan speed. If you don't then put a reducer in there and run it on 6v. My avatar is 12v and the heater fan runs on that without a hitch and has been for 7 years.
 
aussie merc said:
does anyone have any idea how fast the heater fan should spin on high [car was converted to 12 volt but no idea about any bolt ons [found radio had been converted to 12v but wired back into 6v when reassembled ] so it remains to work out the rest figured that rpm would be the easiest to work it out Doesn't seem to move a lot of air on 6v
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Are you saying that the car was converted to 12 volts and then converted back to 6 volts?
If that's the case and a 12 volt reversible motor was installed then it will not run at the same speed as a 6 volt motor.
 
Shoebox Central sells 12-volt replacement motors for the 49 thru 53 cars. If the motor looks relatively new then it may already have been a 12-volt universal replacement. The fan will run twice as fast on 12-volt if it's wound for 6-volt. A 12-volt motor should run at approximately the same speed as the OEM 6-volt did if wound correctly. If it has a big voltage reducing resistor in the switch feed then it is likely still a 6-volt motor. Small resistors on some switches were used to reduce motor speed for a 2-speed blower effect.
 
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I know that rotowrench i just need an approximate RPM so i can work out what goes 34pkup the car was and is 12v as stated radio was converted but when reinstalled it was wired to 6V No wonder it didnt work .This all happened prior to acquiring the car so some questions remain as to the rest of what was changed to 12v and what wasnt [absolute crap conversion quality parts just nil ideas ]
 
Ok, I have just bought an original style heater to suit a 46-48 Ford, so I am presuming it is still 6 Volt, so will I burn the motor out if I run it through a 12 volt system or will it just spin too fast and not heat the car efficiently.

Aussie Bill
 
multi problems 1 yes it will run to fast and generally start to vibrate and shake its self to death 2 yes it will probably burn out the motor and the controller that what im trying to avoid so if anyone can give me an approximate speed it would be helpful
 
aussie merc said:
multi problems 1 yes it will run to fast and generally start to vibrate and shake its self to death 2 yes it will probably burn out the motor and the controller that what im trying to avoid so if anyone can give me an approximate speed it would be helpful
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I have been running my original 6 volt/2 speed motor on 12 volts when needed for over 20 years.
When can I expect it to "vibrate and shake its self to death" and "burn out the motor and the controller"?
Could you please provide an approximate speed your motor runs at so others can make a comparison?
 
just me back again Took a while but managed to jam this fat backside under the dash so we came up with 1200rpm at 6.5 volts
 
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