My Nitro Pool Vacuum Advnetures!

About  a month ago, I found a Nitro pool vacuum on Craigslist for $25 that did not work.  Turned out to have several problems.  The first problem was the blue power cord.  The conductors were broken right where the cord enters the vacuum.  I think this is the reason for the warning to not use the cord to lift the unit out of the water.  Pull very gently on the cord!
This is a very special cord that is designed to float.  The outer casing is actually a special foamed material and the 10 conductors inside are insulated aluminum!  This is to help the floating.  Well, I cant solder aluminum, and the 10 conductors are not separated from one another.  You will need to test each conductor with a meter or test light to separate them.  Next, any new connections need to be made with a crimp, not solder.  After all that, I re-sealed the cord ends with silicone and epoxy.  Now I have power!

I tossed it in the pool, and it took off.  Yay, success!  But wait, all it would do is just move back and forth a couple of feet and then pop a wheelie, move back and forth a couple of more feet and pop a wheelie, rinse and repeat for all eternity!

The problem ended up being the front wheel sensors.  They were no longer operating.  The back and forth motion is the vacuums  computer attempting to get the unit unstuck from something.  If the unit is running, and the front wheels come off the pool bottom, the unit will go into this "un-sticking" routine.  My problem was the reed switch sensors in the front wheels were not installed correctly from the factory.  Reed switches open and close in the presence of a magnet.  In this case, the magnet is located in the wheel itself.  The wires that connect these to the controller were cut back too far and water got into the “sealed” switch board and ruined the little circuit boards.  Here are some pics of the reed switches, the circuit boards, the front wheels and my fix.

If you are handy and have access to tools, you can dig into the system and glue in new ones, re-solder wires, and re-seal the wire harness. Note: I did not attempt to re-use the circuit boards, I just soldered the new wires directly to the reed switches.

 I re-installed the outer and inner wheel assemblies with a 1/4" X 20 nylon bolt and nut.  The only good thing about this attachment scheme is that if it goes bad again, I can dis-assemble the wheels to service the switches!

This was necessary because freeing the reed switches required destroying the glue joints that hold the wheel assembly together.  However, be warned, this is not for the faint of heart. You will need access to tools like drills, dremels, adhesive, sealers, etc.  

This is a link to the short video I shot of the cleaner working after the repair.  Note: this is an 8X speed video!, they really dont go that fast:
https://www.youtube.com/watch?v=zF81StdgCQA