Water valve controller disasembly

I bet it's not clogged my manual set is 4 or 5 books black and green colors . Taken plenty of these out . I've air here and in low out coolant passages on autos all the time seen big clots of shiet hot the wall as I do. It . Never in any model of Prius . I do not know why. Unless stop leak added . I guess I been lucky not to have worked on one those I guess.

 

I'd love to hear you bleed a big load of snot out a you're cooling system or valve .

 

Got that! Thanks!

Because the valve has a mechanical stop this means the controller ECU is capable of driving the motor in both directions by reversing the polarity of the voltage which feeds it.

Important: Do not use a high powered 12v source for testing the valve with 12V applied directly to the motor wires (black and red). This might strip the plastic gears when the valve hits the mechanical stop (or if the valve is totally stuck in one position). I expect normal operating current is <1 amp. Connecting a conventional (incandescent) 12V brake light bulb in series with the motor while testing should be sufficient protection. The brightness of the bulb indicates how much drag there is. The bulb should be dim when the valve is rotating and get brighter when the valve hits the mechanical stop. I'll test this and post my result.

Another testing idea which came to me: Observing +/- polarity at the motor drive wires tells which direction it is rotating. I might cobble together a super-simple tester from a pair of LEDs wired back-to-back in parallel along with a series resistor. There should be a consistent pattern of LED blinking when the valve operates properly. However, if the motor is stalled by a stuck valve I would expect the polarity to rapidly fluctuate between + and - while the ECU attempts to get the valve to rotate. If the position sensor switch has dirty contacts the + and - may also randomly reverse while the ECU tries to get the valve into the desired position. Off-topic note: simple LED testers are often used for troubleshooting "inverter" mini-split air conditioners. Such testers have 6 LEDs in them. Because the compressor motor in these mini-split air conditioners receives 3-phase power at a variable frequency, the pattern and speed these 6 LEDs blink at tells a lot about what is happening inside the unit.

 

Sure hope you take pictures or make a video...

The video that was already shared in this thread made it pretty easy to understand how debris in the system would cause the valve to not work... And as @ChapmanF has verified the most common problem we've seen with these is claimed to be the sensor and the resultant floopy-disk drive sound of the system malfunctioning or as he called it "hunting back and forth." And how we can we actually prove that claim by looking at the physical sensor, something that has never seemed to have been done? Or has it? What exactly has worn out? Maybe hunting back and forth sound is just the symptom of the valve being jammed with debris and the there's never been a sensor problem, just a motor sending pulses of current to rotate something that's no longer able to rotate? As in maybe the faulty sensor notion is BS?

And also, how can we look at the switch of a failed pump to determine that its circuit is the source of the failure?

In hindsight when I've replaced the 3-way valves on cars that have gone years without the valve working I shouldn't of used hose clamps and should of drained the whole system to prevent debris from shortening the lifespan of the new pump. However this doesn't entirely explain why the cars that have gone the longest without this valve functioning activate that pump far less frequently, even after factory reset by disconnecting the battery?

 

What pump ? This is a 3 way valve diverts coolant as positioned . Me no see no pump . Well there's a few . But it not this part chs tank pumps I line I think . But unless humans adding clogs they generally do not happen here. Ie stop leaks

 

Apologies... I fixed that typo... I used the word pump when I should of used the word valve.

 

So if it's halved all is good operationally . A lite mite be on but won't keep us from driving. And coolant will flow and do its job . This is just for fun of it none mine are broke at all . 8 just gutted a broke valve and did what I said to it . Lite won't make any difference to some it mite be a few until re inspection