Magnetic speed sensor Help

[vauxviva]

I bought this 1980's accessory off eBay called a cal custom performance timer

it's new in the box but missing the magnetic speed sensor

I have the magnets that fit to the prop shaft, it's just missing the electronic sensor seen in pic below, does anybody know where can I get a suitable sensor from?

Thanks

[ejenner]

I'd try it with any old sensor and see how it goes.

You should be able to see whether it wants 2 or 3 terminals on the sensor and just get something similar from a motorfactors. In the past my local friendly motor factor has let me go into their storage area and look through all the sensors they had until I found something I liked the look of.

The other thing you might consider is splicing it into the speed sensor on the car you are fitting it to. A lot of them read from the gearbox although more modern cars will have x4 wheel speed sensors. Some have both.

As it's a universal fit device so you should be able to calibrate it.

[squonk]

Knowing how many wires the original probe had may help in getting something that is compatible. If it has three wires it is probably going to give a TTL square wave pulse output. If it is two wires it is probably a zero crossing sinusoidal output. Do you have a wiring diagram for the system?

[Deleted]

Would it be possible to use one from a bicycle speedo?

[vauxviva]

Thanks for reply's

the sensor is a two wire

I found this on eBay, it looks to be what I need but I don't really want to spend £28

www.ebay.co.uk/itm/Rostra-250-4165-Vehicle-Speed-Sensor-2-Wire-Magnetic-Pickup-Universal-Each-/390803253974?pt=Motors_Car_Truck_Parts_Accessories&hash=item5afdb06ad6

I spent hours last night looking through proximity sensors on eBay but all seem to be 3 wire, I found some two wire ones but they where using iron for the trigger not magnetic so wouldn't work

I am not familiar with what sensors are on modern cars, do they use something similar to this?

looks like the sensor I need is a two wire with magnetic trigger

I thought about bicycle sensor but would the prop shaft not spin too fast for sensor to pick up?

any help appreciated

[RobinJI]

B5 Passat's use a 2 wire sensor for the speedo which might be worth a look.

[Deleted]

Mar 31, 2014 19:20:56 GMT vauxviva said:

I thought about bicycle sensor but would the prop shaft not spin too fast for sensor to pick up?

In theory no because you set them on a trial and error basis (the ones I have used need to know the bike wheel size so calculate the speed from that so you would set it as a very small wheel size)
In practice I'm not sure because I have only used them when the magnet is on the hub or wheel on motorbikes and cars , On cars its not 100% accurate that way but it doesn't have to be legally.