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adding electric fan to mazda 929s


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James_85_jr
User

Mar 23, 2010, 10:15 PM

Post #1 of 5 (1642 views)
post icon adding electric fan to mazda 929s Sign In

I am adding a electric fan to my mazda 929 it is a 91 model and i have been having a hard time keeping a good clutch fan on the car it keeps breaking the bolts holding it onto the water pump so i'm adding a electric fan and was wondering if this wiring would work to control the fan speed and turn it on when the engine gets warm

i have used this successfully on computers with different components the mosfet is built to withstand 40v at 85a so i know it will hold the power i added fuses and relays to turn the power off to the circuit when the key is turned off so it doesn't accidently drain my battery or short out

can anyone help with this before i install the wiring just incase i missed something
Attachments: attachment icon simple fan control modified for car.gif (7.31 KB)


nickwarner
Veteran / Moderator
nickwarner profile image

Mar 23, 2010, 11:08 PM

Post #2 of 5 (1639 views)
Re: adding electric fan to mazda 929s Sign In

Perhaps I'm not as up to date as I am but this looks like it will run the fans anytime ignition is on. This lower temp engine will run rich and plug the cat in no time, along with causing driveability trouble before that. What you need is to get a conversion kit with a sensor that screws into the engine to monitor temps and actuate the relay only when needed. By doing so, you keep the engine cooled and at optimum temp. Others with a better reading of this schematic please feel free to correct what I have posted.


James_85_jr
User

Mar 24, 2010, 1:53 PM

Post #3 of 5 (1638 views)
Re: adding electric fan to mazda 929s Sign In

the relay just turns the power on to the circuit but the ntc is a thermosistor the makes the mosfet act like a variable switch the warmer the engine the more power goes through the thermosistor to the mosfet then takes that voltage and boosts amperage so the fan in theory will kick on slowly at a preset temp determined by the 10k pot and as the temp rises the faster the fan runs until they equal out the relay just turns power off to the circuit when the key is off incase the thermosistor burns out the fan reverts to high and wont shut off


fordtech
User

Mar 24, 2010, 5:20 PM

Post #4 of 5 (1635 views)
Re: adding electric fan to mazda 929s Sign In

might be easier to figure out as to why the bolts keep breaking or switch to a different grade bolt.


James_85_jr
User

Mar 25, 2010, 10:52 AM

Post #5 of 5 (1630 views)
Re: adding electric fan to mazda 929s Sign In

i always thought the bolts broke because the fan was so heavy the thing weighed about 10 lbs and the bolts are the size of tooth picks when the bolts broke it wasn't like it threw the fan off the fan simply fell strait down like the engine started turning and the fan never had time to catch up Unsure






 
 
 






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