24V Heater blower resistor

[tornio]

HI , I forgot to write that the resistor must be 4 ohm ( or little less) but it may be any wattage more than 50w so if you find in the junkbox a 3-4 ohm resistor more than 50w will be ok because it has to dissipate only 50w bj joule effects

if you find a more resistive power resistor you can calculate the power required using the formulas in my previous post

more ohm = more watt / heat to dissipate

ps the rtt is an 30 years old MAGGIOLINA.

In the photo you can't see how much is rusty !!! the chassis is full of holes , i saw here in the forum a lot of beatiful restauration projects and one day i'll start whit mine....

stefano

 

[Solace in Solitude]

hi guys , this is my first post ... so after have received a lot of help from all the forum (THANK'S) I want to help solve this little problem :

IF the blower is 100w let me say :

to reduce to +/- half speed we need half voltage so a 24v 100w motor need +/- 4,2 A

to drop half voltage ( r=v/a ) we need r = 2.85

the power dissipation of this resistor must be (w=va) 4,2 x 12 = 50.4 w

but somebody can say : why Toyota put 4 ohm instead of 3 ? I don't know why but :

normally the blower is on when also the engine is on .... so the voltage now is almost 28v

load 100w 28v is 3,5 amper

TO REDUCE TO HALF : 14V / 3,5A = 4 ohm

the power required is 14 x 3.5 = 49 w so 50w resistor is the same

how you say " this is only my little cent' "

Thank's to all guys !!!! an sorry for my english , (i want improve it)

this is my rusty rusty rusty 1983 bj42 180k km stock

Hi Stefano!

Thank you for all this great information!!

To answer your question (yellow, above), we say, "that's my two cents" or "that's my $.02".

Thanks again!