Hi,
I need to look for car speed pulse cable for different kind of car. Could I use a pulse generator(around 5v) connect to all wires in car to check which wire is speed pulse cable? Should I turn on the car power or not? Will it damage car?

Thanks

 

I'm not sure I understand what you are looking for. You have a car and you are looking for a spped signal?
If so, which one? Engine speed (cranks sensor), wheel speed (ABS sensor), vehicle speed( transmission output)? Can you be more specific? In this day and age, we have lots of sensors for lots of things on cars.
Maybe explain what you are grying to do.

 

Thanks for your reply. I am looking for vehicle speed pulse output for some old vehicles(car, bus and truck) which do not use can bus. Final purpose is to install Mobileye(ADAS system). Currently we need to make vehicle to move and check the wire one by one, but it is time-consuming and dangerous. So I am thinking a way to find the wire easier and safety.
So if I am thinking if I can give signals to wire to check and don't need move vehicle, should be able to save lots of time.

 

Axel stands... Since I am assuming yoiu don't have a rolling road.
I am assuming you have a method of measuring the pulse, all you need is the wheels moving with the car stationary.

Can you not find wiring diagrams for the older cars?

To be honest I dont really understand the question, motors / pulses?

If yoiu know where the pickup is than finding the other end of that wire shouldn't be hard.
If yoiu are talking about simulating a pickup to look for a pulse elsewhere than that will likely be dependent on the speciffic pickup on diferent cars but in theory you could inject a signal with the pickup disconnected, once you know what to inject.

To get a better answer you are going to need to give more detail.

Al

 

When you say pulse generator do you mean tone generator like this?:

https://www.monoprice.com/Product?p...MIoLLumZuU1QIVxEGGCh0uEgXgEAkYDiABEgJtgvD_BwE

 

Axel stands... Since I am assuming yoiu don't have a rolling road.
I am assuming you have a method of measuring the pulse, all you need is the wheels moving with the car stationary.

Can you not find wiring diagrams for the older cars?

To be honest I dont really understand the question, motors / pulses?

If yoiu know where the pickup is than finding the other end of that wire shouldn't be hard.
If yoiu are talking about simulating a pickup to look for a pulse elsewhere than that will likely be dependent on the speciffic pickup on diferent cars but in theory you could inject a signal with the pickup disconnected, once you know what to inject.

To get a better answer you are going to need to give more detail.

Al

We need to move different customer site and the site conditions do not have rolling road or equipment to lift car. Either wiring diagram is not available usually. It will be great if we can have a good way to find speed pulse wire without moving car.

 

When you say pulse generator do you mean tone generator like this?:

https://www.monoprice.com/Product?p...MIoLLumZuU1QIVxEGGCh0uEgXgEAkYDiABEgJtgvD_BwE

the pulse frequency should be 50-200hz, attached is too high.

 

the pulse frequency should be 50-200hz, attached is too high.

Ok if you're specifying a frequency then I dont understand what you're trying to do. Are you trying to simulate the speed pulse? If so, why? How does that help you locate the wire?

 

Ok if you're specifying a frequency then I dont understand what you're trying to do. Are you trying to simulate the speed pulse? If so, why? How does that help you locate the wire?

Hi,

I have a pulse simulation module to provide pulse signal. I just think if I can use the module to find speed pulse wire in car which do need to move car.

I am thinking to output the pulse signal to wire one by one, if the speedmeter change value, then I can know the wire is speed wire. Maybe I also can turn off car power but not sure. I am not sure if this work or damage car.

 

Hi,

I have a pulse simulation module to provide pulse signal. I just think if I can use the module to find speed pulse wire in car which do need to move car.

I am thinking to output the pulse signal to wire one by one, if the speedmeter change value, then I can know the wire is speed wire. Maybe I also can turn off car power but not sure. I am not sure if this work or damage car.

how is that any easier than checking the wires one by one with a multimeter?

 

how is that any easier than checking the wires one by one with a multimeter?

My point is if possible no move the car and find cable.

 

Aren't we overthinking this? If this is an older car, the vehicle speed signal is generally going to come from the vehicle speed sensor located in the back of the transmission on the output flange. It will be wired to the vehicle ECM so if you can find the speed sensor, you can take note of the wire colors and find them at the ECM.
If the speed signal comes from the ABS, same thind except it may go to an ABS controller from the wheel speed sensor found at the wheels. The fact that you are on this forum tells me you have the internet and there are tons of diagrams available now as well as forums to assist you with location of parts. If not sure, lost here, we will help you find the information. Make, model, year, engine size should be all that is needed.

 

Aren't we overthinking this? If this is an older car, the vehicle speed signal is generally going to come from the vehicle speed sensor located in the back of the transmission on the output flange. It will be wired to the vehicle ECM so if you can find the speed sensor, you can take note of the wire colors and find them at the ECM.
If the speed signal comes from the ABS, same thind except it may go to an ABS controller from the wheel speed sensor found at the wheels. The fact that you are on this forum tells me you have the internet and there are tons of diagrams available now as well as forums to assist you with location of parts. If not sure, lost here, we will help you find the information. Make, model, year, engine size should be all that is needed.

Thanks all of you for discussion and useful suggestions. I will try it. The most trouble for us is some local made bus which is hard to find the wire and installation time is limited. It is welcome if any new method to try.