If you have been following the history of the SVO Golf here on The Smart Drive you will know it was a total mess when it was purchased. The original Greasecar kit installation is no exception to this. It’s clear to me, the previous owner (or who ever installed the kit) had a limited understanding of automotive electrical systems; it is amazing this car ever burned SVO. Some major problems with the system included WAY too many ground wires, some gauges and sensors had grounds run multiple feet back to the battery. Also, there were mismatched gauge wires everywhere using almost entirely green wire, with tons of crimps and melted electrical tape; it’s called zip-tie people! There was even a solid gauge wire run from the battery crimped to stranded wire using a barrel connector to the ~10A in-line fuel heater. Since the barrel crimp only had small points of contact on the solid wire it was no surprise it was partially melted.
Since the engine in the car is pretty much new I wanted to take some time after it was fixed to break it in running regular #2 petrol-diesel; that and life, moving and a new job got in the way 
. Right now there are 2,500 miles on the new engine and it’s time to get this puppy running on vegetable oil! A few weeks ago I pulled out almost all of the SVO system from Greasecar to start over and do it my way. I plan on keeping the hose-in-hose SVO lines and rear tank since they are already in the car but everything else is going to be modified. This weekend I spent some time getting things pretty far along.
The Greasecar kit is interesting in how they do things. Greasecar only uses a single fuel line from the tank to the engine, there is no return line. I spent some good time searching, but I couldn’t find any resources on how Greasecar suggests hooking up the fuel lines to their solenoids and since they don’t sell their instruction manual I settled for the install DVD. The original kit uses two solenoids and a three position switch to enable three driving modes, diesel, vegetable oil and purge mode. The first two are obvious but the last is a little different. Since it is NOT a good idea to shut off on SVO before stopping the engine you need to purge the system of SVO. Some conversions just switch back to diesel and let the fuel burn off, using two solenoids and a three position switch you can push the SVO out via the return line using diesel from the main tank. Take a look at these diagrams for how the Greasecar setup works.
Diagrams: Running Diesel, Running SVO, Purge mode
At first purge mode might look a little off since it will push diesel into the SVO system, but since mixing diesel and vegetable oil is the equivalent of “blending” it is not something to worry about. Hooking up the solenoids with the interior switch without a diagram or instructions is a little tricky. While the system has three states there are really only two powered states. Each side of the rocker switch connects the double poles on the back to the common poles in the middle of the switch. Since solenoid B must be on for both running and purging this needs to be connected to both sides of the switch, solenoid A only needs to be on one side. Hook power from the ignition into the center poles on the switch and a single ground wire to the 7th connector on the side. Take a look at the diagram here. Each side of the switch powers the light for the other side. It’s a matter of preference which light is on for SVO or purge so feel free to switch the connections for the solenoids if you want.
I don’t have a WVO filter setup built yet (that is two weekends away) so this week I am flushing out the system using a full tank of regular diesel. This also gives me time to get used to fake purging the system before shutdown, which isn’t a bad idea, i’ve already shutdown on the second tank twice good thing it is diesel. That’s it for now.