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Speedometer Component Testing

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etemplet

etemplet

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I'm trying to test speedometer components for the paddle wheel type speedo. Does anyone know how to test the "paddle wheel pick up" to determine if it is working?? I was testing with the multi-meter and only got a reading in milliamps but it was inconsistent. I tried a couple of paddle wheels. I can't really see them going bad but if I understood more how they work I could figure that out. LOL Problem is that they are so difficult to remove. Those six screws seldom cooperate.

Can a take a reading when I spin the "pick up wheel"? What range would I use on the meter?
If you spin the wheel with the engine running should the speedo register?

Help is appreciated.
 
Thanks man !! I've been searching.... but I can't seem to get the right words in there for a good hit. LOL
 
Great thread to get me started. I've tried to remove the whole block from the ride plate and can never get all of the screws out. The threaded inserts always end up spinning. I think I left these on the last two skis I scrapped. They are that much of a pain to remove. Should I be replacing the whole piece or just the sensor?
 
I don't have speedometers on my skis, I could care less about it, they're never right. Just a waste of time and money.

Keep your Google search straight and to the point. You can even throw seadooforum at the end.
db2142c4cdc41ceb638f1207f3df0b79.jpg
 
Here;s a schematic of the internals of the sensor. Depending on year, typically earlier than this, the design might differ. I use a 2.2k resistor in series with an LED to limit current from a 12V source for bench testing. The LED flashes as the paddle wheel is spun.


Speedometer Sensor Hall Effect.jpg
 
That;s why I am not getting readings with the volt meter. I thought I had something in MA but it wasn't consistent. I've been thinking of getting a variable voltage power supply. I'm not electronic guru but I can muddle through some things. LOL

I have a lot of parts and gauges so I'd like to try to fix at least my own speedometer. If I ever get the chance to work on my ski that is. Ha ha
 
Voltmeter in Ohms scale by itself isn't going to test a good pickup, both voltage and current will be too low to operate the IC.

It's been quite a while since I repaired my speed sensor but if you need I can breadboard the circuit I used and test if my memory is correct. It was only 2 components in addition to the pickup.

I may have used a 9V battery, I probably did but it's been that long I don't recall. 12V should work fine as well, I just scraped some stuff out of the drawer and threw it together on a breadboard for a quick test.

The current path went from the power supply through a 2.2K resistor (to limit current to max of device spec I=E/R=0.005A), through a forward biased LED diode (additional ~0.7V drop), then to the pickup module purple/yellow wire. The black/orange wire of pickup is ground (to neg terminal of power supply).

The key here is to use a resistor to limit current, otherwise the 3-pin integrated circuit hall effect device inside will be damaged. I may have used a 1k resistor, but 2.2k is a safer choice to avoid damage, I may have begun the test using a 2.2k then moved to 1K to increase current to 0.012A.

Just can't exceed the device current and voltage ratings, the 1/2W zener and the IC can't dissipate more current than they were designed for (formula is W=A*V ; 0.5 = A*5.6Vzd), thus A max = 0.089A) Keeping current under, say less than 1/2 that (0.044A) and there's no chance of damage.

I can check the IC datasheet to confirm it's current capacity and make a final recommendation based on your power supply voltage (12 or 9v?).
 
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I read the device is 5 volts but don't hold me to it. :) Thanks for the help for sure. I'm just looking for a way to test which component is causing the problem. The pick up or the gauge. Soon I"ll be working on the info gauges. :)
 
If you have the pickup installed on the ski and all the electronics are in place, you can just measure the voltage of the purple/yellow wire as you rotate the paddle wheel, this voltage will switch back and forth between 5.8 and 10V

I think the device can handle over 24V but let me dig out the data sheet.
 
According to the datasheet, the IC can sink up to 0.025A and voltage operation range is 4.5V to 24V So you have to limit current to 25mA Based on this, a 1K resistor lands you well in the safe current range (12.5/1,000 = 0.0125A)
 
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I finally got around to checking my speedometer sending unit (paddle wheel) Looks like that part is working. Not sure when I'm gonna get busy on the gauge end. I'm not reading speed on the INFO gauge or Speedometer.
 
Speedo wires from the sensor are cut on the 2000 RX. Module looks different than the previous unless it was removed. I wouldn't mind working on these if I could EVER get the screws removed from the ride plate. What a pain.
 
I agree but it is a way I measure performance. I don't really trust the speedo's on the Seadoos, I use my mobile phone app. LOL. Speedos LIE big.
 
Candoo makes a plug in replacement GPS module that connects to your stock wiring and drives your speedometer but uses GPS speed instead of the inaccurate paddle wheel. $125-$150 depending on model.

CandooPro GPS Speedometer Modules : PWC Performance Parts

I emailed them about my '95 Speedster earlier in the year and they said that they have some other models not listed on the above link so even if your machine is not listed, drop them a line.

Doug M
 
I wonder how hard it would be to emulate this with an arduino and gps module....

Only tricky part I can think of is the 5-10 v switching. I mean it's the pulse rate that would determine the speed but if I understand this correctly the signal is either open circuit or its shunted slightly down to 5 v. The arduino could do that easily and simply convert one signal from the gps chip to an on/off signal that looks like a square wave.
 
My speedo is not working on a 97 GTX, lots of good information on this thread!

I checked the pickup as instructed in the shop manual, and there is a voltage fluctuation but it is just between 7.3 and 7.5 VDC, is that too small of a variance for the speedos to pickup?

The infocenter digital speedo nor the analogue gauge report any speed whatsoever.

Does it need to jump from 0 to 4 or 5VDC for it to register?

Is there a way to send a pulse to the speedometer to see if it is working OK, I don't see any checks in the shop manual for the speedos?

I like the idea of the Candoo GPS module, but I don't want to spend that much if the gauge is bad. Since both do not report anything I am thinking it is not the gauge(s).

Thanks
 
When I checked mine it had a larger fluctuation that you record. I did buy the Candoo module but have not installed it. I have 2 skis with speedo's that don't read. 2000 RX and a 1996 GTX. I may piddle with them this week.
 
I start by spinning the wheel and looking for DC voltage on my meter, Then, knowing that the pick up is good, I put the key on and spin the wheel again. If there is no response on the speedo gauge while spinning the wheel, then the gauge is at fault.
 
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