How-To: No Codes-Do It yourself Fan Mod Instructions!

[JimTurner]

ALL:

I have completed my Fan Mod design and was going to post in the morning after taking a quick peak at an SRT8, but since there has been a lot if interest, here you go:

http://members.cox.net/jdturneriii/300C/LXFanMod.pdf

** PLEASE NOTE THAT I HAVE NOT LOOKED AT THE SRT WIRING TO SEE IF THIS APPLIES OR NOT **

The Mod will offer you the following characteristics:

1. NO SPLICING INTO THE WIRING HARNESS! <-- A plus for me
2. NO CODES!
3. BOTH FANS ON HIGH WHEN ENGAGED!
4. OPTIONAL CONTROL WIRING to give you the following:
a. Turn Fans On ONLY When Engine is running
b. Turn Fans On Regardless of Engine State
c. Wire for BOTH options a. and b. (Slightly more complex wiring but not that bad).

I spent somewhere between $30 and $40 for the parts for this.

I've had this mod installed on my car for over 2 weeks and it works great.

Here is a picture of the installation.



Please let me know if you have any questions.

Regards and Happy Cooling!

jimt

[JimTurner]

Originally Posted by Moose

1. How long have you been using the mod?

I've had the mod on for about 3 weeks.

Originally Posted by Moose

2. With the mod in place, if something fails on this mod, or fuse blows, will you get a code (so operator knows before overheat)?

With both fans running on High, I can hear them going. Doing one final test the other night, I left the fan plug un-coupled and drove around without overheating. I tried to turn them on to cool the engine as I pulled into my neighborhood, and did not hear the fans.

Assuming that you DON'T do what I just explained, you should hear the fans running. If not, simply turn the switch off, and your stock fan control will re-engage.

jimt

[JimTurner]

Originally Posted by JustForFun

Jim Turner,

That is an INCRDIBLE document there!!! WOW.

...

Thanks for the great instructions.

JFF

Thanks!

Originally Posted by JustForFun

Do you make documents for a living?? If not - you should. Very NICE job.

I run large software development projects for a living. User requirements,, system documentation, user documentation, etc. are the things that influence what you see here.

Besides, I was trying to put myself in the readers position not knowing ANYTHING about the invasiveness of this mod.

jimt

[JimTurner]

Originally Posted by oilman

jimt

This is very impressive and a very elegant approach. I have already printed it out in preparation for installing it.

Before I do that, I was wondering about an alternate approach and since you have clearly done a lot of work on this, you might know the answer. What does the stock system use for temperature monitoring? Could we change the input at that side which would turn on the fans at 180 deg instead of the 210 deg it goes on now. I would think that would be an easier approach and make it more automatic.

Thanks again for sharing your hard work.

I think that the temperature is controlled by the PCM/ECM/FCM network of computers, code, etc. I think that a starscan or equiv. would be required to change the setpoint of the temperature control system. While I think I have the skills to get into this, I don't have the equipment necessary to start poking around in the 'puters of the LX platform. (Although, I would LOVE to do just that! )

When doing my research for parts, etc. I came across this:

http://www.autospeed.com/shop/catego...svr=1034821012


Scroll down to the Economy Adjustable Temperature Switch product about the 3rd one down.

I thought about connecting this to the Relay Control Ciruit in my mod, and having it govern the on/off of the fans using my controls.

There would be a couple of challenges though:

1. Finding a place to mount the unit (pretty simple really)
2. Finding a place for the Thermocouple on this to grab the temperature of the engine compartment/water/?? for control.
3. Without the digital readout, setting the on/off points on the temperature control would likely have to be done by trial and error.

I have NOT ordered this to play with. My initial goal for the fan mod was to keep the thing under $50. This would have put the costs over the top, but would have given in essence a secondary fan control system.

I now have 2 mods available, the simpler version costing $10-15 in parts. There are also outstanding requests for a switched "Both on Low", "One on High", and "Both on High" controls for the fans. Stay tuned

I think I found a switch that would fit that purpose as well, but I have been out of town for over a week and haven't even SAT in my 300C let alone drive it or tinker with it.

jimt <-- Having LX 300C withdrawals

[JimTurner]

Originally Posted by EXTREME-SRT8

This is an old thread, but well worth a BUMP i think!!

I'm planning to do this soon as i get some supplies in! Any progress on teh both on low switch, JT?

The "Both on Low" would only use relay #1. It runs both fans in series. The way that the stock fans work, both come on low with relay 1 engaged, one on high with 1 and 2, and both on high with 1,2, and 3. SO, if you want the Both on Low option, do not engage relay's 2 and 3.

Originally Posted by GEN XER

He said he did not know if it worked on the SRT's. I would wait to see what is answer is regarding the circuitry.

I have completed my Fan Mod design and was going to post in the morning after taking a quick peak at an SRT8, but since there has been a lot if interest....

** PLEASE NOTE THAT I HAVE NOT LOOKED AT THE SRT WIRING TO SEE IF THIS APPLIES OR NOT **

This works for the SRT's as well, but the wiring is different colors (as heavier wiring is used on the Stock SRT wiring harness for the harsher conditions).

Hope this helps.

jimt