Variable Fan speed controller 12v dc

Thread Starter

Automan350

Joined Jun 15, 2015
60
Hi! I am wanting to retrofit two cooling fans into my 80s chevy truck. Issue is I really want to control the fan speed. I know these fans come from a vehicle that uses a 50 amp fuse or breaker as circuit protection. I would like to be able to use the fans at 60% and 100% of the fan speed. I figure a max of 750 watts is what they will pull. can you all help me create a speed controller? I am good at soldering and am mechanically inclined. this will be used on a 12v-14.5v system Thanks!
 

Thread Starter

Automan350

Joined Jun 15, 2015
60
Anyone?

I will assume all liability on me and not take anyone at fault if something goes wrong. its really a project I want to do for my family to show them you can do anything you put your mind to...
 

Georacer

Joined Nov 25, 2009
5,182
Hello Automan350,

Commonly in our forum, an answer might arrive several hours later. I suggest you wait a bit, until another member takes interest in your problem.
 

Thread Starter

Automan350

Joined Jun 15, 2015
60
Yes sir both together. The fans will be from a dodge charger. when they are in the charger they operate a two speeds. originally I wanted to mimic those two speeds via resistor, but I see it is not that easy. Thus I come to the forums here for help.
 

Dr.killjoy

Joined Apr 28, 2013
1,196
Yes sir both together. The fans will be from a dodge charger. when they are in the charger they operate a two speeds. originally I wanted to mimic those two speeds via resistor, but I see it is not that easy. Thus I come to the forums here for help.
I work on cars,trucks,and diesels.. What you are asking for info involves alot tech data cause of the start up rush current and normal operating current. Check out summit racing or jegs for a fan controller cause by the time you figure out how to build a proper controller the it will cost alot more in parts,time,and testing .. Also you could try using a ford turus fan controller which alot of people use and grab from junk yards..
 

JoeJester

Joined Apr 26, 2005
4,390
I would have thought the PWM was controlled by a temperature sensor, so the link that automan found might not be what he needs.
 

Dr.killjoy

Joined Apr 28, 2013
1,196
I would have thought the PWM was controlled by a temperature sensor, so the link that automan found might not be what he needs.
No cause the max watts is 720 for 12v and for that setup it will be on the edge or over cause of the charging voltage and the rush current and operating current..You also have to watch cause sometimes those fans pull alot more current than posted..
 

Thread Starter

Automan350

Joined Jun 15, 2015
60
I work on cars,trucks,and diesels.. What you are asking for info involves alot tech data cause of the start up rush current and normal operating current. Check out summit racing or jegs for a fan controller cause by the time you figure out how to build a proper controller the it will cost alot more in parts,time,and testing .. Also you could try using a ford turus fan controller which alot of people use and grab from junk yards..
Hey thanks I am mainly interested in a variable voltage controller that won't cost me an arm an leg. I have seen the ones that summit and kegs have to offer and really don't want to spend hundreds if i can make it or buy it for less. I guess what your s saying is i will need a voltage regulator ahead of this controller i am looking at?
 

Thread Starter

Automan350

Joined Jun 15, 2015
60
Ok do if you do the math with 50 amps and 12 volts the watts come out to 600 watts
With 50 amps and 14 volts it comes out to 700 watts. This should be ok correct? Either way the fuse is rated for 50 amps and i highly doubt the fans will draw that or it wouldn't be safe to be mass produced and sold in to the public correct? Please correct me if I am wrong.
 
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