using in line resistors for sensors

Bucko · Post by **Bucko** » Wed May 21, 2014 6:25 pm

Hi first time poster, I am using the GM temp sensors recommended and need clarification on installation of the 2 wire sensors using the resistor recommended for the race capture pro.Do I need a resistor for each sensor or just one coming from the 5v reference fed and branch out to all sensors? thanks

Post by **brentp** » Wed Jul 23, 2014 7:29 pm

Hi,

You definitely need one resistor per sensor to create the correct voltage divider effect.

theycallmetk · Post by **theycallmetk** » Sun Mar 13, 2016 6:59 am

Brent,

I just bought a system with 2 temperature sensors, 1 pressure sensor, hall effect sensor and AFR as well as coil X. the sensors are all connecting right to my engine block and then wires going back to the system.

can you recommend where I could find the right resistors to buy and how many i need / the right wiring configuration.

I believe i may have missed this when i was reading about installation.

Post by **brentp** » Mon Mar 14, 2016 5:39 am

Hi,

You only need pull-up resistors for your temperature sensors. We have a guide here on how to use the pull up resistors here. https://autosportlabs.net/RaceCapturePr ... ure_Sensor

Not sure where you live; If you have a radio shack near you you can find the 2.2k resistors there.

We also have the SensorX breakout board that can make wiring up your sensors a bit easier: https://www.autosportlabs.com/product/s ... out-board/

-Brent

theycallmetk · Post by **theycallmetk** » Mon Mar 14, 2016 9:13 pm

okay thank you for the quick response. I will look for a 2.2 kohm pull up resistor for the temperature sensors.

how else would i wire the resister in without the break out board? just by soldering it in series with the 5v reference before it goes back to the unit?

do you have a wiring diagram for the break out board?

sorry, this electronics stuff is not my strong suit. mechanical engineer who failed Electric circuits my first stab at it ! haha

Post by **brentp** » Mon Mar 14, 2016 9:18 pm

Doing it by hand just involves soldering and heat shrink. The documentation on the breakout board is light, but the SensorX board itself is fairly self explanatory with the inputs and outputs.

theycallmetk · Post by **theycallmetk** » Mon Mar 14, 2016 9:51 pm

i just ordered breakout board from you with the 5 included resistors.

the way it looks. I can connect all my sensors 5V references / grounds to this board. then just attach 1 ground and 1 5V Vref into the Race capture unit itself?

thanks for your help.

theycallmetk · Post by **theycallmetk** » Mon Mar 14, 2016 10:05 pm

last question Brent, sorry couldnt find a better place to post it.

when connecting the Racecapture unit itself to power / ground. I saw somewhere someone said they used a 18AWG wire. but in the installation instructions it doesnt mention anything for the wire just 9-18V, 5am fused connection.

Would you recommend 18AWG shielded wire? or just the 24 AWG millspec shielded.

tfriest · Post by **tfriest** » Mon Mar 13, 2017 3:34 pm

What wattage resistors should I use for the temperature sensor pull-up resistor?

I haven't seen any mention on this site, but I did find another site that mentioned wattage would be 0.1 or less...
I'm having to drive 40 minutes to a radioshack to get resistors (and that one is closing soon too), so I'd like to get resistors that work (I assume I have a choice between 1/8, 1/4 and 1/2 and maybe even higher watt resistors)...

Post by **brentp** » Fri Mar 24, 2017 1:25 am

A common 1/4 watt resistor is fine.