So i picked up my first seadoo, turned out vts was busted.
Previous owner ended up cutting all the wires off the module and wiring his cheap relay fix.
Unfortunately this disabled the gauge and limit stops were not active.
Nozzle would 'unscrew' in the lowest position and would not come back up without physical help.
Well there is lots of information about the TrimFix module and/or cheap relay bypass fix.
TrimFix only gives you 4 positions for the gauge, and its over $150 shipped (im from Canada)
But i haven't seen anything about actually fixing the original module.
So i decided to give it a go since i had nothing to loose.
Long story short, i fixed it. Its quite easy if you have basic electronics knowledge and know how to solder.
Here is how you do it:
1. Scrape the upper layer of epoxy to expose the PCB
Most people give up here... its actually pretty easy and it comes off in big chunks once you have it heated up to higher temperature. I Used a heat gun.
2. De-solder 2 relays and a varistor, make sure pins wiggle freely inside the vias (relay pins, varistor pins, double check with a needle nose) . There is a lot of epoxy under the PCB and you wont be able to pull the board up with relays and varistor attached. Idea is so desolder them, then pull the board up, leaving relays and varistor in the epoxy underneath.
3. Remove 4 mounting screw holding the PCB in place.
20191126_163843.jpg
Above picture was taken after the fix was done, this is just for reference to see what to desolder in order to pull the board out.
4. Once the only one thing holding the board in are the wire terminals, gently pry the board from the top by sliding a long screwdriver underneath and pulling. Be careful not to damage components under the board. I used a small hook pick and pulled only on the edges of the board.
Keep working your way up until you can see the wires underneath that are holding it in place.
5. Fit a small side cutter under the board and start cutting the wires. Once all wires are cut board will come out .
Keep the heat gun handy while you do this. Keep the board nice and hot, just dont burn it.
Alternatively you can cut off some of the plastic housing to gain access to the wires under the board. You will re-seal everything later on so that won matter too much.
Take your time, keep the board hot with a heat gun, it will come out.
Resized_20191120_171225.jpeg
This is probably the hardest thing out of the whole process...disconnecting that board.
Take your time, You will most definitely damage some vias , traces etc, you will need to inspect it afterwards and repair all broken connections.
As you can see my board had some water damage and serious short that left a hole in the PCB.
6. Clean the board up with some steel wool and isopropyl alcohol.
20191122_162749.jpg
7.Locate your shorts, look for burnt spots.
As you can see, my board got fried on the relay connections and on the resistor bridge right beside the reed switches.
I ended up buying all new relays, new reed switches as some of them did not test good with a volt meter when magnet was presented, and all resistors.
parts used :
Reed switches : ORD 324/10-15 AT
Relays: CB1-P-12V
resistors for reed switch bridge:
MFR-25FBF52-14R3
all ordered from digikey
Rest of the board consists of simple transistor circuitry and some zener diodes, you may test them all with a multi meter but odds are they will be fine as they are located away from a possible water contact area.
8. Fix your traces, replace all broken parts. Make sure your connection vias are conducting, especially on relay pins as they would get damaged when board was pulled out.
I use super glue to fix badly burnt PCB's. Sand lightly with steel wool after glue sets, then repair traces with solder wick or a wire.
20191126_163929.jpg
9. reconnect your wires, use new wires, just make sure you label each of them accordingly to the wiring diagram from service manual.
20191126_163923.jpg
Color codes are (from bottom =1, to top =10)
1:brown-white -gauge connection 1
2
urple-white -accessory 12v for transistor supply
3:green red -motor 1
4:green white - switch 1
5:black (ground)
6:black (ground)
7:brown-black gauge signal 2
8:blue-red motor 2
9:blue-white Switch2 if i remember correctly
10: red white 12V for relay supply
Refer to your service manual wiring diagram to see what they do. I could be wrong, im writing from my memory.
Wire numbers/ position in the PCB are 100% correct tho.
10. Test your board!
Hook up 12V to purple-white and red white.
Connect your motor leads and ground.
connect ground wire to each switch wire, this will imitate the switch for UP and DOWN. motor should move.
11. Dig up the rest of the epoxy still stuck in the housing. Re-install the board in the housing.
Install the shaft and the motor back inside the housing and test it again.
Your shaft should stop on limit switches and you should read resistance on brown white- brown black ranging from 15Ohms to 160 Ohms depending on the position.
Now all you have to do is re-seal everything and you're done.
To re-seal it, use clear nail polish and brush few coats on the entire board, let it dry, then cover everything in silicone.
This is the cheapest way without using potting compounds.
The whole process took me just under 5 hours and $40CAD . Its not that complicated, but like i said you need to have some experience with electronics.
Hope this will help someone in the future!
Good luck!
I (stupidly) put a 10amp fuse in instead of 7.5amp so tbh Im a little scared to see my board.
