electric fan switch mod?
08-16-2013, 06:10 AM
#16
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Year: 1999
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Yes, it will work on SOME XJs. Not on mine. The fan runs fine until you switch on the A/C and it trips a CEL every time. Diode or no diode, I get a CEL. It took me no longer to run my relay than it did for you to dig out the correct pink/blue wire. Same time to run the switch. To each his own. I tried the "trick the PCM route" with the pink/blue wire to ground. My Jeep didn't like it, so I just wired in a switch and now I can run the fan anytime I want and it still comes on with the A/C when its supposed to and also when the temp reaches 218, even if my switch is off.
08-17-2013, 10:15 AM
#19
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08-25-2013, 06:34 PM
#20
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Year: 1998
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Yes, it will work on SOME XJs. Not on mine. The fan runs fine until you switch on the A/C and it trips a CEL every time. Diode or no diode, I get a CEL. It took me no longer to run my relay than it did for you to dig out the correct pink/blue wire. Same time to run the switch. To each his own. I tried the "trick the PCM route" with the pink/blue wire to ground. My Jeep didn't like it, so I just wired in a switch and now I can run the fan anytime I want and it still comes on with the A/C when its supposed to and also when the temp reaches 218, even if my switch is off.
Can you provide a diagram of what type of switch and relay you used? And how you wired it in? I like the idea of this but I don't understand it 100%. PIcs would even be better.
04-04-2016, 09:39 PM
#22
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I'm still not sure why you guys screw around with trying to trick the PCM and tripping CELs and stuff.
Its simple...
Get a switch and relay. Wire the switch to trip the relay and splice it in to the hot wire on the fan right at the fan itself. The PCM will still work to turn it on when it is hot or the ac requires, but your switch will allow you to run the fan when you want. If you power the switch to trip the relay with a "always hot" wire, you can run the fan with the engine off for a few minutes to keep air flowing over the motor. Works great with hood vents.
If you power the switch with an ignition controlled power source, you wont have to worry about forgetting to turn it off.
This works with ALL model years and I have yet to see it trigger a CEl.
LEAVE the PCM ALONE!
Its simple...
Get a switch and relay. Wire the switch to trip the relay and splice it in to the hot wire on the fan right at the fan itself. The PCM will still work to turn it on when it is hot or the ac requires, but your switch will allow you to run the fan when you want. If you power the switch to trip the relay with a "always hot" wire, you can run the fan with the engine off for a few minutes to keep air flowing over the motor. Works great with hood vents.
If you power the switch with an ignition controlled power source, you wont have to worry about forgetting to turn it off.
This works with ALL model years and I have yet to see it trigger a CEl.
LEAVE the PCM ALONE!
05-24-2016, 05:35 AM
#25
Beach Bum
I tried the "trick the PCM route" with the pink/blue wire to ground. My Jeep didn't like it, so I just wired in a switch and now I can run the fan anytime I want and it still comes on with the A/C when its supposed to and also when the temp reaches 218, even if my switch is off.
If you power the switch to trip the relay with a "always hot" wire, you can run the fan with the engine off for a few minutes to keep air flowing over the motor. Works great with hood vents.
If you power the switch with an ignition controlled power source, you wont have to worry about forgetting to turn it off.
This works with ALL model years and I have yet to see it trigger a CEl.
If you power the switch with an ignition controlled power source, you wont have to worry about forgetting to turn it off.
This works with ALL model years and I have yet to see it trigger a CEl.
11-11-2016, 10:03 PM
#26
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Jamison,
"My Jeep didn't like it, so I just wired in a switch and now I can run the fan anytime I want and it still comes on with the A/C when its supposed to and also when the temp reaches 218, even if my switch is off."
Could you help me with the fan switch mod you did on your 2000? Being a novice mechanic, I could really use some specific instructions on how to do this. I'm having the heat soak/vapor lock problem and need some circulating air to cool under the hood. Thanks in advance!
"My Jeep didn't like it, so I just wired in a switch and now I can run the fan anytime I want and it still comes on with the A/C when its supposed to and also when the temp reaches 218, even if my switch is off."
Could you help me with the fan switch mod you did on your 2000? Being a novice mechanic, I could really use some specific instructions on how to do this. I'm having the heat soak/vapor lock problem and need some circulating air to cool under the hood. Thanks in advance!
11-12-2016, 05:18 PM
#27
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
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If you are not isolating the existing circuit with either a relay (preferred) or diodes, you are doing it wrong, and asking for trouble.
Here's one right way.
Here's one right way.
12-16-2016, 01:38 PM
#28
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If you are not isolating the existing circuit with either a relay (preferred) or diodes, you are doing it wrong, and asking for trouble.
Here's one right way.
Here's one right way.
tsd fix didn't really work for me. i really think my xj doesn't like winter fuel. i did do the delay fan mod , if i get a couple requests i can make a video showing function , i used a turbo timer instead of the other delay timers that are on this forum.. use relay and diode also. pm me so i can get motivated to make a youtube video. it cost me 20 dollars to make and has a digital display and is easy to set the time.. let me know guys. check out my channel on youtube if you get a chance. https://www.youtube.com/channel/UCSv...view_as=public
12-16-2016, 08:28 PM
#29
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Year: 1998
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If you are not isolating the existing circuit with either a relay (preferred) or diodes, you are doing it wrong, and asking for trouble.
Here's one right way.
Here's one right way.
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