Fan wiring

For discussing how to choose sensors and create a wiring harness for all Bowling and Grippo versions of the MegaSquirt® EFI controller.
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skyy406
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Fan wiring

Post by skyy406 »

Hey all

I am nearly done my wiring for my MSII and I have a question. I have read a few topics about electric fan wiring but none of them seem to talk about what i'm after. I want to wire the fans in such a way that they only turn on at a specific coolant temperature, and turn off at another specific coolant temperature. Is this possible? I don't want them tied to my A/C when it's on- and I don't want to have to run a seperate switch ato turn them on manually.

Thank you for your help.
1998 Dodge Avenger ES with 6g75 swap and a543 transmission--- Megasquirt II
2005 Dodge Ram SRT-10 Quad Cab- Magnaflow, Q-forms, Components, 7" indash DVD
2007 Honda CBR1000RR- Power Commander, Custom Acura TSX HID, K&N, Michelin Pilot Powers
kjones6039
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Re: Fan wiring

Post by kjones6039 »

Assuming that you will be using one of the spare ports to control your fan(s):

Under Output Port Settings in MT or TS you can set the temperature where you want the fans to come on and go off entirely independent of a/c etc.

Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
skyy406
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Re: Fan wiring

Post by skyy406 »

Spare ports?
1998 Dodge Avenger ES with 6g75 swap and a543 transmission--- Megasquirt II
2005 Dodge Ram SRT-10 Quad Cab- Magnaflow, Q-forms, Components, 7" indash DVD
2007 Honda CBR1000RR- Power Commander, Custom Acura TSX HID, K&N, Michelin Pilot Powers
kjones6039
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Re: Fan wiring

Post by kjones6039 »

The manual page on spare port configuration is here:

http://www.megamanual.com/ms2/spare.htm

Many are using the FIdle port for controlling their fans because it will drive an automotive relay without having to add any transistors etc.

What version MS are you using?

Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
patrickbrown
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Re: Fan wiring

Post by patrickbrown »

I use my fidle port for this and it works great. I turn the fan on at 180. With a 10 degree hysteresis the fan turns back off at 170.
Patrick Brown

MS2-V3 (2.891) - EDIS8
62 Ford Falcon - 331 Stroker
xbmwguy
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Re: Fan wiring

Post by xbmwguy »

i too would like to turn on or give a 12 v signal to an idle valve but am using my fidle wire for boost . it seems s1,s2 always have 12v. ihave tried to use these and the valve stays on. any ideas?
kjones6039
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Re: Fan wiring

Post by kjones6039 »

it seems s1,s2 always have 12v. ihave tried to use these and the valve stays on.
Those are not outputs AFAIK. Are you using a stepper motor for IAC?

Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
xbmwguy
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Re: Fan wiring

Post by xbmwguy »

hey ken dont think it is a stepper its closed with no power and open with 12 v. i cant use fidle as its controlling my ebc i have ms2 and 3.0 thanks the old girl has a hard time keeping idle when cold
kjones6039
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Re: Fan wiring

Post by kjones6039 »

xbmwguy wrote:hey ken dont think it is a stepper its closed with no power and open with 12 v. i cant use fidle as its controlling my ebc i have ms2 and 3.0 thanks the old girl has a hard time keeping idle when cold
If you are not using a stepper motor you can use IAC 1 & IAC 2 for outputs. (used in the same way as FIdle)

In your case I would use FIdle for exactly that and use one of the IAC outputs for your fan. You will then be left with one unused output to control whatever you like.

Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
xbmwguy
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Posts: 18
Joined: Tue Feb 15, 2011 10:45 am

Re: Fan wiring

Post by xbmwguy »

ken i cant use the Fidle as it is working my ebc. when i try to program one of the iac functions it doesnt turn off. i trid setting it at coolant ,less than 120 and hysterisis at 3. i am lost any help would be appreciated, thanks
kjones6039
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Re: Fan wiring

Post by kjones6039 »

xbmwguy wrote:ken i cant use the Fidle as it is working my ebc. when i try to program one of the iac functions it doesnt turn off. i trid setting it at coolant ,less than 120 and hysterisis at 3. i am lost any help would be appreciated, thanks
I am not familiar with the acronym "ebc". :oops: What sort of control is it?

Did you power off/on the MS after you tried to set the IAC output? What are the Power On/Trigger Values?

Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
xbmwguy
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Posts: 18
Joined: Tue Feb 15, 2011 10:45 am

Re: Fan wiring

Post by xbmwguy »

ken ebc is electronic boost control. the car is a 87 porsche 930.just trying to figure out s1,s2,s3,s4. the switch is an on off and i have power there constantly. thanks
skyy406
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Joined: Wed Apr 28, 2010 11:00 am
Location: Ocala, FL

Re: Fan wiring

Post by skyy406 »

Would a spare Fuel Pump relay that I have, be good to use for the fans using the F-idle circuit?
1998 Dodge Avenger ES with 6g75 swap and a543 transmission--- Megasquirt II
2005 Dodge Ram SRT-10 Quad Cab- Magnaflow, Q-forms, Components, 7" indash DVD
2007 Honda CBR1000RR- Power Commander, Custom Acura TSX HID, K&N, Michelin Pilot Powers
kjones6039
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Posts: 618
Joined: Sat Jul 22, 2006 7:02 pm
Location: Eureka, Nevada USA
Contact:

Re: Fan wiring

Post by kjones6039 »

skyy406 wrote:Would a spare Fuel Pump relay that I have, be good to use for the fans using the F-idle circuit?
Yes, if it can handle the fan current. I personally prefer to use a relay that is intended for controlling fans though. In my experience cooling fans pull considerable current.

Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
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