Seadoo XP VTS Circuit Rebuild

This page shows how I re-built the VTS circuit. The schematic was obtained from the excellent article about the VTS system at http://www.sea-doo.net/techarticles/vts/index.html.

First I opened the VTS cover and hooked the DC motor directly to the battery to make sure it moved up and down OK. Once that was verified, I checked the Up/Down switch for continuity. I also checked the power going to the circuit. I checked continuity from the motor power. This was about 17 ohms, almost a direct short. The 6.5A fuse was blown. This proved the electronics were fried. Therefore I re-built the circuit from scratch for $32.63. However this took a very very long time to build, test and connect - approximately 16 hours total.

PARTS LIST

TOTAL COST:     $32.63

Comments:

Relay The relay are Panasonic automotive relays built for harsh conditions. They can take 40A resistive load. I believe the originals could take 30A. This should be more than adequate for the 4A inductive load of the DC motor. I had to cut out the epoxy perf board to mount the relays due to their large pin sizes.

Reed Switch - The reed switch I used are 14mm which are some the longest ones I could find available for cheap. These are still shorter than the originals, but seem to work fine. I choose the more sensisitive 10-15AT magnetic range. I do not know what the originals were. The moving linear shaft needs to be mounted to the motor to center the shaft. Otherwise the reed switches may not pick up the magnetic signal from the permanent magnet.

Resistors - Any resistors will do as long as they are through hole and are equal to or larger to 1/4 Watt. Any tolerance value will do.

ASSEMBLY

First I removed the VTS system from the pwc. I tried to pry the potting compound from the PCB board. I was able to get most of it off the top, but since it is also glued in from the bottom, I was not able to take the original circuit board out. Instead I ended up drilling through it with a variety of drill sizes. A dremel tool would have been ideal to remove the circuit board and components. Do not bother trying to remove the PCB board in one piece. I have no idea how the writer of the above article did it. This step took about 3 hours. It would have been much quicker if I knew from the start to not destroy the circuit board and if I had a dremel.

One of the relays was visibly burnt. It burnt a hole straight through the circuit board. Once the circuit and components were removed I had to repair some holes I made to the plastic with epoxy.

All components were purchased from Mouser and mounted on perforated epoxy board. The reed switches are not identical to the original, but worked ok. Their length is not as long as the originals. The relays are Panasonic relays, equivalent to the originals. Most of the parts do not need to be exact replacements. I used redundant end of limit reed switches. In other words I used two reed switches for each end of limit in case one failed for some reason.

The bottom was wired with 28AWG wire wrap wire, soldered to each component. The heavier power and motor wire is 20AWG. I think Seadoo used 18AWG.

A clear plastic cover was sealed on the top with silicon to seal it from water.

Everything works as expected. The circuit was tested with a power supply on the bench before installing it. It drives to both end limits and then stops as expected. Took the ski out, and everything works perfect. I also have easy access to the circuit and components in case anything dies in the future.