Electronic speedometer sensor, faulty or not ?
Discussion
Hi,
Need to fix a speedo on my Marcos, the speedo is a CAI electronic model from their Eclipse range, the speedo lights up and shows the mileage on the digital read out but does not register any speed when driving.
I have looked at the sensor and the 3 wires seem okay and it sits against the propshaft bolts, i assume it takes a reading from the bolts rather than something attached to the propshaft.
Is there any test i can do to see if the sensor is faulty, i bought the car as a non runner and its been off the road for 4 years so assume it was working beforehand,
Regards,
Martyn.
Need to fix a speedo on my Marcos, the speedo is a CAI electronic model from their Eclipse range, the speedo lights up and shows the mileage on the digital read out but does not register any speed when driving.
I have looked at the sensor and the 3 wires seem okay and it sits against the propshaft bolts, i assume it takes a reading from the bolts rather than something attached to the propshaft.
Is there any test i can do to see if the sensor is faulty, i bought the car as a non runner and its been off the road for 4 years so assume it was working beforehand,
Regards,
Martyn.
Martyn-123 said:
Hi,
Need to fix a speedo on my Marcos, the speedo is a CAI electronic model from their Eclipse range, the speedo lights up and shows the mileage on the digital read out but does not register any speed when driving.
I have looked at the sensor and the 3 wires seem okay and it sits against the propshaft bolts, i assume it takes a reading from the bolts rather than something attached to the propshaft.
Is there any test i can do to see if the sensor is faulty, i bought the car as a non runner and its been off the road for 4 years so assume it was working beforehand,
Regards,
Martyn.
So you are saying the odometer still registers you are covering distance, but the actual speedo doesnt work ?Need to fix a speedo on my Marcos, the speedo is a CAI electronic model from their Eclipse range, the speedo lights up and shows the mileage on the digital read out but does not register any speed when driving.
I have looked at the sensor and the 3 wires seem okay and it sits against the propshaft bolts, i assume it takes a reading from the bolts rather than something attached to the propshaft.
Is there any test i can do to see if the sensor is faulty, i bought the car as a non runner and its been off the road for 4 years so assume it was working beforehand,
Regards,
Martyn.
Hi,
No the odometer is not counting miles, i just get a miles done so far on the readout meaning i have power to the actual unit.
This tells me it is a sensor problem, i not sure whether the sensor is broken, too far from the propshaft bolts ? The bolts are plated, would this make a difference ? Should i have a magnet on the propshaft, has it come off ?
Regards,
Martyn...
No the odometer is not counting miles, i just get a miles done so far on the readout meaning i have power to the actual unit.
This tells me it is a sensor problem, i not sure whether the sensor is broken, too far from the propshaft bolts ? The bolts are plated, would this make a difference ? Should i have a magnet on the propshaft, has it come off ?
Regards,
Martyn...
Sounds like a simple hall sensor. Your problem could be sensor or wiring related.
Normally it will have a power feed ( anywhere 5-12v ), a ground and then a signal return. It will simply read off the bolts, which need to be ferrous metal. ie magnetic.
You can test with a simple volt meter. Power and ground are obvious
On the signal return, test between ground and signal and you should see it switching between 0 and 5v as the metal passes the face of the sensor.
Normally it will have a power feed ( anywhere 5-12v ), a ground and then a signal return. It will simply read off the bolts, which need to be ferrous metal. ie magnetic.
You can test with a simple volt meter. Power and ground are obvious
On the signal return, test between ground and signal and you should see it switching between 0 and 5v as the metal passes the face of the sensor.
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