Need Help With Electric Fan On A 68 Mustang

Discussion in '1965 - 1973 Classic Mustangs -General/Talk-' started by MustangMando, Sep 27, 2013.

  1. Installed a Spal electric fan on my 68 mustang and a relay from autozone.I ran fan direct to make sure its not the fan and it woks fine. The fan seems to turn real slow as if it needs more amps? Installed a 75 amp external reglated alternatr and the voltage regulator is getting hot. I followed wire car has original voltage regulator
    Thanks for Any info
    #1 MustangMando, Sep 27, 2013
    Last edited: Sep 27, 2013
  2. My instument cluster is dimming too. Should i upgrade my alternator to a bigger one, if so from what make or model(95amp)
    #2 MustangMando, Sep 27, 2013
    Last edited: Sep 27, 2013
  3. First measure voltage with a meter to see the voltage at the fan.Sounds like its drawing too much current.
  4. yep, first check your current draw, then check your grounds, then check the hot wire gauge you used to power the fan through the relay, it should be at least 14 gauge, and 12 gauge would be better. also what amp relay did you use? it should be a 40amp minimum, some fans require larger.

    as for the alternator, you should have something more like 130 amp output, electric fans tend to take a lot of electricity to run.
  5. I can exchange the alt for a 100amp external regulated, at my local oreillys . What make or model would be a good fit?
  6. actually i would suggest a 3G alternator with an internal regulator from something like a taurus or a 94-95 5.0 mustang.