Hello Luis,
Thank you very much for your input... I installed the system in 2006 or so and then sold the car on 2010. It was working perfectly. I just got the car back... The problem before was that the motors would work together but the additional pump would not... So, I decided to take the control unit apart and look for any traces of corrosion or burnt circuit paths and found none except slight corrosion/gunk on both sides which I cleaned... Then, I unplugged each connector for the motors and they were clean. Just added some dielectric grease and put back together... After that, I gave it a go and voilà now it works as it should...
Now your information is excellent! I can see that you have studied this system better than I... It is nice to actually see it working since most don't and are set up just for looks... Here I thought that the function for the additional pump was controlled by the control unit/relay... I learned something today, thank you. Did you ever installed the system in your car? I would like to see photos... Thank you.