Hello. I just got my WVO system running on my 1986 190D. It consists of a separate aluminum tank with heated pickup, hose in hose fuel line, heated filter jacket, heat exchanger and separate supply and return valves. Anyways, I used to have a VOcontrol, that they have stopped producing, and also left a lot to be desired, so I came up with this...

I used an Arduino and a total of 9 LED's to create a display along with a single switch. The blue row next to the switch is my fuel level gauge that reads off of a sealed sender in my tank. I'm still working out the scale, but it seems to work pretty well. The green light says whether the system is on or not. It blinks when the system is purging, which happens automatically, and the times can be set in the program for switch off or switch on. lastly, the red light under the on/off light blinks when the temperature is below a certain amount. It reads off of a TX3 temp sensor right after my heat exchanger.

I have made it so the system does not purge if the system is ON when you start the car, so there is less fluid swapping when you leave the system on for running in a store or something.

Nothing blinks at you when the system is off and the fuel gauge lights are dimmable if you used ultrabrights like I did.

You can read the serial output with a USB cable that shows you the actual temperature.

Parts involved total between 30-40 bucks. I switched out my Arduino UNO R3 ($25) for a chinese Arduino Nano clone ($5), which works the same, just way smaller. I also used a delay off timer relay to keep the arduino running while cranking, since I couldn't find an always-on accessory wire in the car. I used an adjustable switching voltage regulator to bring the voltage down to 5 volts as to keep the stress off of the onboard regular. These things are optional. I will draw the schematic and post my code if anyone is interested.

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