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The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> Speedo problem
Post Info TOPIC: Speedo problem
micccki


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Speedo problem
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Hi, i know these speedos on th open enduro can be problematic, but mine just went dimmer and not showing any zero or the current mileqage of the bike.  The screen lights up, and i have 12 volts coming in on the red and the brown, but only showing about 1.7 volts on the blue.  I understand this should show 5 volts.  Am i right in thinking that 12 volts gets reduced via the speedo and then goes to the sender and then yellow pulses at + and -5 volts.  Would i be correct in thinking the speedo has had its day  I have checked all the connections etc but remain mystified.  Any help appreciated.  The round magnet is intact but i do not think the problem lies with that as the voltage has not reached there yet.

 

Mike



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TTRfan


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Having (we think!) deciphered the CDi connections, the speedo sensor is fed by a constant 5V by the CDi rather than from the speedo head.

CDi readoutB.jpg

See http://www.ttr250.com/#More_speedo_information although the information seems a bit contradictory in that fastfazer says the blue feeds the speedo sensor confuse

Perhaps take a 12v supply to the brown speedo wire and see if the display comes to life?

Sorry but I no longer have any digital speedo heads to experiment with.

Brian

Speedo head and sender wiring.jpg Wiring colour codes.jpg

PS This is what the FAQ says.

Wiring arrangement for the digital speedo head - courtesy of "fastfazer"!
 Having tested the connections with a multimeter I believe the connections are:
Red + 12v
Brown + 12v
Yellow +5v into the speedo from the speed sensor at the sprocket. This is the pulse wire, the pulse is sent as +5v, -5v, +5v, -5v etc.
Blue +5v out to the speed sensor.
Black/Yellow 0v (Negative) out to the speed sensor.
Black 0v (Negative)
Connecting +12v to the Red wire lights the speedo up but with no LCD display.
Connecting +12v to the Red & Brown lights it up & powers the LCD display.



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micccki


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Thanks for that Brian, i have read the FAQ previously. New to me though about the feed from CDI. The display does light up and there is 12 volts coming through on both the brown and the red, but no digits showing on speed or the odometer reading and trip meter. I do in fact have a reading of just below 5 volts coming in to the speedo sensor on the yellow. Question is though... is my speedo duff.....?? I assume that i should still have readings on the speedo (zero) and trip/odometer if the sensor had gone.

I have been looking at the cheapo Speedos at around £25 on the bay, and also the Trailtech Endurance 11 and also KOSO BB EX2. I will probably go for either of the latter ones around £80. Does anyone have any good experiences with the after market ones. Info much appreciated.
Mike

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ttr steve


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Welcome Mikesmile Nice to talk to you earlier, thought this would be the best place for your question.

Bri I have a dead speedo here we could do an autopsy on next time I see you.

Steve



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TTRfan


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micccki wrote:

Thanks for that Brian, i have read the FAQ previously. New to me though about the feed from CDI. The display does light up and there is 12 volts coming through on both the brown and the red, but no digits showing on speed or the odometer reading and trip meter. I do in fact have a reading of just below 5 volts coming in to the speedo sensor on the yellow. Question is though... is my speedo duff.....?? I assume that i should still have readings on the speedo (zero) and trip/odometer if the sensor had gone. 

Mike

Hi Mike

Yeah - sadly it sounds like you have a dead speedo cry  

If Steve doesn't mind, it would be really good if you could send it to him so that we can test it on his digital speedo TTR and I can review the FAQ information to make sure it is correct! 

That would be really helpful biggrin

Brian



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ttr steve


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TTRfan wrote:
micccki wrote:

Thanks for that Brian, i have read the FAQ previously. New to me though about the feed from CDI. The display does light up and there is 12 volts coming through on both the brown and the red, but no digits showing on speed or the odometer reading and trip meter. I do in fact have a reading of just below 5 volts coming in to the speedo sensor on the yellow. Question is though... is my speedo duff.....?? I assume that i should still have readings on the speedo (zero) and trip/odometer if the sensor had gone. 

Mike

Hi Mike

Yeah - sadly it sounds like you have a dead speedo cry  

If Steve doesn't mind, it would be really good if you could send it to him so that we can test it on his digital speedo TTR and I can review the FAQ information to make sure it is correct! 

That would be really helpful biggrin

Brian

 Happy to pay the postagesmile



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micccki


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Hi again, i am going to have a fiddle around for a while, but got my eye on trailtech vapor or striker. Vapor seems better value, but i dont need a rev counter so maybe better quality in striker??? I'll keep you posted.
Cheers.
mike

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micccki


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Fitted a Trail tech Vapor the other week, with TTR idiot lights.

www.ttr250.activeboard.com/t63528559/after-market-speedos/

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