Why do speedo transducer fail ?
Discussion
My speedo is not working anymore and searching PH, it looks as its a typical problem of the transducer. But what is the real problem with the transducer ? Does it loose its magnetic force, do the cables break or what else ? (My cables and connectors are ok)
I removed the meter and transducer to make some measurements.
Counter shows 613 pulses from the generator at 50mph.
The signal from the generator is set to about 4 volts peak-peak.
If I go below this level the speedo stops immediately. If I increase the generator frequency, the speedo follows but may all of a sudden stop, increasing the voltage will bring it back.
When I measure the transducer, the resistance is about 377 Ohm and moving metal over it, produces a signal of just above 4 volts (peak-peak, without load). Are these parts really at edge of working ?
Peter
I removed the meter and transducer to make some measurements.
Counter shows 613 pulses from the generator at 50mph.
The signal from the generator is set to about 4 volts peak-peak.
If I go below this level the speedo stops immediately. If I increase the generator frequency, the speedo follows but may all of a sudden stop, increasing the voltage will bring it back.
When I measure the transducer, the resistance is about 377 Ohm and moving metal over it, produces a signal of just above 4 volts (peak-peak, without load). Are these parts really at edge of working ?
Peter
The main failure mode is crashing the reluctor ring due to excessive run-out. However, I have been using a longer more sensitive transducer that allows for a much wider gap and still produces 5V output. I have sold several of these to other owners and have an advert in the classifieds.
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