Check engine light when fan switched on ... :(
Thread Starter
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Check engine light when fan switched on ... :(
Anyway to fix this?? :confused:
I jumpered what's in red. Works the way i want it to (fan comes on when ignition is set to "on" ) and it keeps the temp at 194 idling without A/C on... but i have a check engine light because of it.
How do i fix this? Also, i bought a 12v Zener diode... it would probably be wise to stick this on my jumper, huh?
[Modified by GlockLT4, 7:56 PM 4/14/2003]
I jumpered what's in red. Works the way i want it to (fan comes on when ignition is set to "on" ) and it keeps the temp at 194 idling without A/C on... but i have a check engine light because of it.
How do i fix this? Also, i bought a 12v Zener diode... it would probably be wise to stick this on my jumper, huh?
[Modified by GlockLT4, 7:56 PM 4/14/2003]
Le Mans Master
Joined: Aug 1999
Posts: 7,339
Likes: 137
From: WilkesBarre PA
Re: Check engine light when fan switched on ... :( (GlockLT4)
If you jump the factory relay on a OBD2 car you will get a light. The computer expects to read a certain resistance in the relay when cold,and when hot. By you energizing the relay already, then the computer energizing it it sees the wrong resistance and it throws a code. You may be able to get around it by wiring in another relay parallel to the factory one. I know a few do this at the track with the car off, but don't know if works with the car running.
Thread Starter
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Re: Check engine light when fan switched on ... :( (RichS)
Hmmm... ok thanks. I don't like having a check engine light on all the time just incase something serious were need to make it's presence with that light ... but i also would like to keep her cool.
Any idea how these guys are running a relay parallel? Just buy another relay and hook the computer up to it and ground the relay that is really hooked up to the fan without the dark green wire attached?
Any idea how these guys are running a relay parallel? Just buy another relay and hook the computer up to it and ground the relay that is really hooked up to the fan without the dark green wire attached?
Thread Starter
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Re: Check engine light when fan switched on ... :( (GlockLT4)
Oh, and what about the possibility of trying to figure out the resistance it expects and adding a resistor on to the dark green wire going to the computer to correct it?
Thread Starter
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Re: Check engine light when fan switched on ... :( (ski_dwn_it)
Glock,
Where have you been? Not sure about your problem...good to see you again. :cheers:
Where have you been? Not sure about your problem...good to see you again. :cheers:
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Melting Slicks
Joined: Apr 2000
Posts: 3,198
Likes: 2
From: Northern CA
Re: Check engine light when fan switched on ... :( (GlockLT4)
If it's due to the PCM looking for a certain coil impedance, I would try hooking up a 30/40A relay like this:
#85 to 12V (try not to use the FAN fuse)
#86 to ground
#30 to #30 on the fan relay
#87 to #87 on the fan relay
Put your switch on the 12V or ground wire
That will allow the fans to "bypass" the original relay, and the PCM will never "see" the new circuit.
#85 to 12V (try not to use the FAN fuse)
#86 to ground
#30 to #30 on the fan relay
#87 to #87 on the fan relay
Put your switch on the 12V or ground wire
That will allow the fans to "bypass" the original relay, and the PCM will never "see" the new circuit.
