Speed sensor

[jackerman]

Hello fellow tmers. I have a question about our speed sensors in a 555. Should they have ohms of resistance if they are not spinning. I’m having trouble getting megasquirt to read speed. I have no resistance until it’s spinning. Any help is much appreciated

[cordes]

That's right. I think there should be continuity 8 times per revolution on the sensor. The stock computer counts the pulses I believe.

[chromguy]

The stock computer counts the pulses I believe.

[Aries_Turbo]

the stock sensor is just a reed switch and a rotating magnet.

the sensor will connect the speed sensor pins as the magnet passes the reed switch.

put your meter in ohms across the pins and spin the sensor gear slowly to see if continuity changes with rotation.

if not, the sensor is bad. you can pry it apart and solder in a new reed switch if you dont want to locate one.

Brian

[chromguy]

if not, the sensor is bad. you can pry it apart and solder in a new reed switch if you dont want to locate one.

Brian

http://minimopar.net/speedsensor.html
I was planing to use a 91+ VSS, just need to add a 8V power line from the ECU.

[tryingbe]

Hello fellow tmers. I have a question about our speed sensors in a 555. Should they have ohms of resistance if they are not spinning. I’m having trouble getting megasquirt to read speed. I have no resistance until it’s spinning. Any help is much appreciated

Which Megasquirt? MS2 or Microsquirt doesn't read VSS.

[jackerman]

I’m running ms3pr evo

[tryingbe]

I’m running ms3pr evo

MS3 Pro Evo manual says it needs a hall sensor.
https://www.ampefi.com/wp-content/up...evo_manual.pdf

So install a 3 wire hall VSS into your car. 5v, ground, and signal. Then send the signal to MS3
http://www.minimopar.net/speedsensor.html#upgrade



I installed a 3 wire hall VSS in my A555 years ago after I had 2 two wire VSS fails.

[Aries_Turbo]

http://minimopar.net/speedsensor.html
I was planing to use a 91+ VSS, just need to add a 8V power line from the ECU.

my reliant still has a cable driven speedo.

Brian