radiator fans....

lvlistchif · Post by **lvlistchif** » Mon Jul 09, 2007 5:30 pm

ok well im doing a srt-4 swap and im wondering with my radiator fans sence im going to be using the stock 2.0's im wondering instead of buying the adapter plug am i able to just plug a power and ground up to it and just always have it run or even throw in a toggle switch so i can turn it on and off and just not plug the harness in it? or does like the ecu need to be able to read that its there because something will go wrong if i dont? also im running megasquirt so ill already be throwing tons of codes as it is.

Post by **Canada** » Mon Jul 09, 2007 6:01 pm

http://forum.2gn.org/viewtopic.php?t=20 ... ht=fan+mod

*Ta-Da*

lvlistchif · Post by **lvlistchif** » Mon Jul 09, 2007 6:53 pm

thats how to run it after its already hooekd up im trying to do it so i dont even have to hook the wiring harness up thats so if the wiring harness is hooked up u can turn it on whenever u want and overrun the computer... i want it so the computer dosent even read it and its not plugged up to the harness.

turbodudey · Post by **turbodudey** » Mon Jul 09, 2007 7:08 pm

Why not just hook it up to the fan output from MS? Then you can program it to automatically switch on and off and whatever temp you want, and you don't have to remember to flip a switch.

Also, the PCM won't care at all if the fan is plugged in to it or not...

lvlistchif · Post by **lvlistchif** » Mon Jul 09, 2007 7:48 pm

do i connect the MS to the power or ground on the radiator fan?

Post by **Canada** » Mon Jul 09, 2007 7:50 pm

Ground

turbodudey · Post by **turbodudey** » Mon Jul 09, 2007 8:07 pm

lvlistchif wrote:do i connect the MS to the power or ground on the radiator fan?

Ground. Always ground. Everything MS does is accomplished by grounding the circuit.

There are several ways to hook it up though. You can't ground the fan directly to MS, as it cannot handle that much current. You'll need to ground the fan control relays. There is a high output relay, a low output relay, and a control relay.

If you don't care about retaining the high/low feature of the fan, then you can just hardwire the fan to the control relay and then used MS to switch it on and off.

If you want to keep the high/low functionality, it would get slightly more complicated...

lvlistchif · Post by **lvlistchif** » Mon Jul 09, 2007 8:15 pm

im confused on what you mean by the high low control relays... were are these at? in the fusebox? how do i even hook those up to the MS im so confused on what you just said by that

edit

i forgot to say that im using the stock 2.0 radiator/fans

turbodudey · Post by **turbodudey** » Mon Jul 09, 2007 9:10 pm

Ah. Oops.

The 2.4L has a two speed fan, but the 2.0L just has a single speed fan.

So, there are no high/low output relays to worry about then.

There is just one relay in the PDC that you would hook up to MS. All you do is wire the ground pin of the excitation coil in the relay to MS instead of the PCM.

lvlistchif · Post by **lvlistchif** » Mon Jul 09, 2007 10:01 pm

ahhh ok i see another question is is the throttle position sensor the one on the top or bottom of the throttble body?

turbodudey · Post by **turbodudey** » Tue Jul 10, 2007 1:17 pm

lvlistchif wrote:ahhh ok i see another question is is the throttle position sensor the one on the top or bottom of the throttble body?

TPS is the only sensor on the TB.

It's on the side of the TB...