MSX 150 Turbo Thermo Temp. Switch Needed

[Koodat]

Anybody have a spare Thermo Temp. Switch they want to part with? P/N - 0451945. If so, send me a note.

[ripcuda]

If you can't find one off the boards here... I saw one on ebay. $110... ouch!

http://www.ebay.com/itm/Polaris-0451945-MSX-110-150-Turbo-Turbocharger-Sensor-Thermo-Temperature

Cheers!

[Koodat]

Yes, I saw that auction. Cannot afford that money. I am thinking of putting a plug in the motor where the switch goes. Put the ski in the water and drive it around. Then with the plug hanging to the wire, heat it with a torch to see if it sets the MFD off.

[ripcuda]

I'd be careful with the torch... seems like you could easily fry the sensor directly heating it. I don't know the triggering temp for that switch but I'm sure a flame it way hotter. That sensor is meant to be immersed in water.

I would first remove the switch and test it in a pot of water on the stove. Use you multimeter as you heat it up to see when the switch goes closed... zero ohms between wire hookup and sensor body. Use a cooking thermometer and you can see the temp this happens at.

To recreate triggering the switch on the ski... you could get a small pot or kettle and fill it with water and dangle the sensor in the water. Then heat the pot with your torch. That would seem safer. Then after you achieve the triggering temp in the pot, see if the ski ECU is registering an overheat condition. Don't melt anything in the hull of the ski while attempting this.

Cheers!

[K447]

Riding a watercraft with the seat off and a torch flame in one hand ... What could possibly go wrong?

[Kosh]

Yes, I saw that auction. Cannot afford that money. I am thinking of putting a plug in the motor where the switch goes. Put the ski in the water and drive it around. Then with the plug hanging to the wire, heat it with a torch to see if it sets the MFD off.

The hole is blind, you can remove it and not need a plug.
It needs to be in contact with the manifold to complete the circuit.

A mutimeter and cigarete lighter will tell you the story, or just pull the wire of the switch when the engine is running, if revs return you have the answer. the switch is normally open, when they fail they seem to in the closed position limiting RPM

[Koodat]

I will run it with the plug out of the sensor and see what happens.

[Koodat]

Well I am about to tackle this agian. I did run it late last year with wire off thermo swich and MFD did nothing and rpms were not limited. So if the hole it blind I can run the ski w/o it in. I am still confused on how to test it. It has to be in or grounded to manifold for me to tes it. These are not cheap, so gotta figure out this out for sure. Suppose I could pull it out, make sure it is touching manifold and put a lighter to the bottom of it? Then check MFD?

[Kosh]

The sensor is normally open, meaning no current will flow at room temperature. If the temperature rises to around 85 Celsius (i am guessing here as i don't have one in front of me, it is marked on the side) the switch will close completing the circuit creating a limp mode.
This is a non fail safe overheat protection feature.

[Koodat]

I hate, I mean hate any limp mode. Sent my ECU to Montreal a few times to clear "phantom" codes and been to dealer twice in last two years to clear codes. When the thermo sensor goes back below 85c. limp mode goes away and ski runs normal?