Electirc fan wiring ???

Discussion in '1974 - 1978 Mustang II Talk & Tech' started by cobraii351, Dec 5, 2003.


  1. cobraii351

    cobraii351 Founding Member

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    Electirc fan question. I installed the 3.8 Taurus electric fan in my cobra. I used the Flex adjust fan control that wraps a capillary tube under the upper rad. hose and has the temp. sense bulb in the water flow into the rad.. Here is my question, I want to put a relay in series with the temp switch so that the fan will only run when the engine is running. Not just the key turned on but the engine actually running. Can I pull the 12V for the relay off the stator wire white w/black tracer that goes to the choke too?

    Thanks guys,

    Tim
  2. Power Surge

    Power Surge Founding Member

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    That sounds like a good idea Tim. As long as that wire has a good solid 12v signal the entire time the car is running, even at idle rpms, you should be ok. If the signal gets weak at idle rpms, then it may buzz or "stutter" the relay (similar to a clicking starter solenoid with a low battery), which is not good and will cause it to fail prematurely.
  3. cobraii351

    cobraii351 Founding Member

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    Thanks Sal. Yeah I guees I need to get a DVM out and check out what that line does. I imagine that even being a little too low would probably be too much of a problem I'm just using this small relay to trigger the 75 amp relay that actually switchs the main power to the fan. The little 12V 30amp 3.99 relay I got from AutoZone would not take the abuse of the couple hundred amp inrush current of that Taurus fan draws until it gets spun up the whole way. I just don't want the thing running and killing the battery if I do something stupid. Not that I would do something like that :rolleyes: !

    Tim
  4. COBRA 7

    COBRA 7 Founding Member

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    You could use an electric oil pressure switch with two leads on it. I believe these were used on mid 80's v-6 G.M. engines. These were used to complete the circut for the electric choke. If the engine died during warm up, the circut to the choke was open. That way the choke would not be wide open on a stalled engine. :cool:
  5. cobraii351

    cobraii351 Founding Member

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    Already have one of those to kill the power to the fuel pump. But a good idea though. Saved my ass one day it did. It vapor locked and it sneezed and popped the roll pin in the dist gear. That sucked.

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