Thread: 2000 WJ electric fan override?

Results 1 to 2 of 2
  1. #1 2000 WJ electric fan override? 
    Junior Member gthaefner's Avatar
    Join Date
    Nov 2004
    Location
    Fort Collins, CO
    Posts
    12
    Rep Power
    0
    2000 WJ 4.7. Has anyone been successful installing a way to turn on the factory fan with a switch? From what I understand, the relay is pulse width modulated from the PCM. I’m looking to actuate 100% for long highway pulls when the mechanical fan doesn’t feel like engaging. Everything is functioning properly in the cooling system, just runs around 215-220 on long uphill grades after installing winch bumper. I would imagine either powering or grounding the control wire to the relay, then installing a diode so voltage/ground does not make it back to the PCM, that way the PCM can still control the fan normally around town for A/C operations with the switch in the off position.

    Thanks!
    94zj locked and loaded
    Reply With Quote  
     

  2. #2 Re: 2000 WJ electric fan override? 
    Senior Member Grand Slam West Planner Ted_Z's Avatar
    Join Date
    May 2007
    Location
    Denver, CO
    Posts
    1,096
    Rep Power
    80
    you wouldn't ever send a PWM signal to a relay coil, just on or off. Switching a relay rapidly is a great way to ruin it.

    I'd just wire a switch in parallel to the PCM output. Figure out if it is sourcing or sinking.
    -Ted Z
    '97 Grand Cherokee Laredo w/ stuff
    '02 Grand Cherokee Limited w/ less stuff
    Quote Originally Posted by Cody View Post
    everytime someone makes a bumper with a stinger, God kills 6 baby Koala's.
    Reply With Quote  
     

Thread Information
Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •