REM Fan Control

Tutorial to use a compatible REM to control Electric Fans to cool your ride!
Youtube video here: https://youtu.be/TMk0DU1BgRE

Starting with the REM II V4 Hardware, A bonus Free Pin system has been added to allow custom projects and further control. Full Extra Pin list here.

With the addition of an upgraded Renix In/Out Adapter, you can control up to 3 fan with the REM for automatic Temperature and A/C Control! This guide will show you everything needed to hook your REM up to your Electric Fans and stay cool.

System Overview:
Need the quick and dirty? Look no further. Notice that the Adapter does not directly control the fan as it cannot handle that much power, instead it will turn a relay on or off from the ground side of the coil.

REM Fan Relay Hookup

If you have a relay already, then find and clip the ground wire from the coil (It could be 85 instead so make sure to CHECK!,) then run a wire from the coil to the adapter and you are ready to go! If not, you can get a relay and a relay socket for pretty cheap from any auto parts store.

Pay attention to which ports are set-up for fan control by checking the diagram later in this tutorial. Once the REM is wired up, go to Options > More > Fans > Setup, and make sure your fan is assigned to the appropriate pin according to this diagram! Then you can go to the fan menu and customize the settings once it is set to [Auto].

Renix In/Out Adapter Setup:
The Renix In/Out Adapter Upgrade adds a port on the side of the adapter for wires to screw into, which we will be running the Fan Relays to. They are built to order, so pop open the lid to check which pins have been setup for fan control. Look for the little black Transistors (Q1-Q3) as they are used to control fan relays (Notice the order is a little scattered.)
REM Adapter Pinout

Modding a Renix Adapter:
The Standard V4 and V4.1 Renix Adapters (Reverse Adapters not included) have provisions to control up to 3 fans. If you would like to upgrade one after it has been ordered, it is possible, but you will have to find a solution to run the fan wires out of the adapter.

Start on the outside components first and work your way in. Make sure the component legs are clipped short so they don’t contact the Diagnostic Pins underneath! Save Pin 1 if you want to read in a 12v signal sometime later in life.

– A Transistor will need to be added to do the actual switching.
– A Diode should be added as well to get rid of any Relay Coil Noise when it opens up.
– Leave the Jumper open as that is only used for reading voltages in.
Transistor PN2222A recommended for it’s higher then average Collector Current.
I use Diode 1N456ATR, but any general purpose diode good to at least 16v will do fine.

 

Preparing the REM:
Now that the In/Out Adapter is wired up, it’s time to setup the REM bits so they will work together. This requires a soldering iron and removal of the REM if it has been installed in a vehicle.


REM II V4.1 Standard and Clock:
The REM II V4.1 boards have a lot of goodies inside, and all 3 pins natively support Fans so it’s a cake walk.

At the Bottom Right (Standard) or Middle Left (Clock) there are Ethernet Jack Breakout pins and jumpers which we will need to make the fan magic happen. With a soldering iron, add a blob of solder to Jumper Pad “A1”, “A2”, and/or “A3” depending on which pins you are using which will connect the Teensy directly to the In/Out Adapter.

Once the 2 Square Pads have been connected then you are done on the REM side. Make sure the 12v or 5v jumpers are blank for the pins you are using to control fans.

Screen Shot 2017-12-20 at 10.27.02 PM

 


REM II V4:
The REM II V4 can only control 1 fan easily due to a pin goof. If you would like to run up to 3 fans then a Jumper Wire will have to be soldered in (MicroSD Slot must NOT be used.)

On the V4 board at the bottom right, there are Ethernet Jack Breakout pins and jumpers which we will need to make the fan magic happen. With a soldering iron, add a blob of solder to Jumper Pad “JA3D” to connect the Teensy to the Jack Pin. Once the 2 Square Pads have been connected then you are done on the REM side for fan 1.

Screen Shot 2017-12-20 at 10.09.47 PM

NOW, If you would like to control more then 1 fan then there is more needed for the other 2 pins. Jumpers JA10 and JA11 don’t support Digital Write which is needed for fans so leave those pads blank; we will have to steal 2 pins directly from the Teensy instead. I have chosen Pins 10 and 12 to be supported.

A wire will need to be soldered from Teensy Pin 10 over to Jack Pin E5 and another wire from Teensy Pin 12 over to Jack Pin E7 (Be VERY careful around the teensy; getting unwanted solder on that board could be a major problem.)

Screen Shot 2017-12-20 at 10.17.58 PM

Now that all the pins have been connected you should be ready to control fans!

 


REM+ V3:
Although the REM+ V3 was not originally designed for such a task, they were built to be mod friendly for such occasions as this. As of Renduinix V0.86, the REM+ V3 can support up to 2 fans after the necessary wires are ran inside the unit and new In/Out Adapter is used.

WARNING: Just be aware that the older REMs are slower and not as reliable as the REM II’s so use caution if this unit is the only thing keeping your engine cool. Some sort of bypass switch from 5V to the E Pin would make a good back-up plan.

On the V3 board at the right, there are Ethernet Jack Breakout pins which we will use to make the fan magic happen. With some spare wire and a soldering iron, a wire will need to be soldered from Metro Mini Pin 13 over to Jack Pin E3 for Fan 1 and another wire from Metro Mini Pin A3 over to Jack Pin E5 for Fan 2. Bonus points that Pin 13 has an SMD LED attached so you can see if it’s working or not!

V3 Fan Wiring

Now that all the pins have been connected you should be ready to control fans!


REM V2 / V1:
Although the REM V2 was not originally designed for such a task, they were built to be mod friendly for such occasions as this. As of Renduinix V0.86, the REM V2 can support up to 2 fans after the necessary wires are ran inside the unit and new In/Out Adapter is used.

The REM V1 was not so lucky and accessing the Jack Pins is extremely tricky as a thin soldering Iron is needed to reach the pins between the board and screen.

WARNING: Just be aware that the older REMs are slower and not as reliable as the REM II’s so use caution if this unit is the only thing keeping your engine cool. Some sort of bypass switch from 5V to the E Pin would make a good back-up plan.

On the V2 board at the right, there are Ethernet Jack Breakout pins which we will use to make the fan magic happen. With some spare wire and a soldering iron, a wire will need to be soldered from Pro Trinket Pin 13 over to Jack Pin E3 for Fan 1 and another wire from Pro Trinket Pin A5 over to Jack Pin E5 for Fan 2. Bonus points that Pin 13 has an SMD LED attached so you can see if it’s working or not!

Now that all the pins have been connected you should be ready to control fans!



REM Software Setup:

Once the REM is wired up, plug it in and go to Options > More > Fans > Setup, and make sure your fan is assigned to the appropriate pin according to the diagram above. Then you can go to each fan menu and customize it’s settings.

You can Manually turn a fan [ON] or [OFF] so it runs all the time. For Automatic control set to [Auto]. You can individually control each fans ON Temperature, OFF Temperature, and if it comes on with the A/C. The Temperature and A/C control comes from the ECU so as long as the factory sensors are good, there are no special sensors that need to be added!

Once any of the Fans are active, an Extra Gauge will appear at the end of the Gauge list to show when the Fans turn on and off so you can keep an eye on them too!