Possible to tap into the 5v source from the FAST to power extra sensors?

[TwinTurboIroc]

i am running a cheap 4 channel EXTERNAL datalogger besides the FAST one and i need a 5v source for them.

I know that the MAP, H20, and IAT all have 5v sources going to them and then going to a wire splice in the harness

you think it would be safe to tap 2 more wires into that splice to get my source?

 

[Craig Smith]

The MAP and TPS have a 5 volt connection but the ATS and CTS do not.

Exactly what would you use the 5 volt signal for? You may be able to do this.

 

[TwinTurboIroc]

i need to datalog an extra IAT and an extra MAP sensor.....

i can artificially create my own 5v source but i figured this would just be easier

the reason why i need a 5v source for the IAT sensor is that my datalogger doesn't datalog thermistors. So, i know, you are asking yourself if it can't datalog thermistors why are you bothering using an IAT and messing with the 5v source?

well, thanks to my friends on the DIY_EFI email list they explained to me that i can install a bias resistor inline with the signal wire to the IAT. Then supply a 5v source to the sensor and then DATALOG that 5v source as it changes with the resistor

Then all i have to do is do a couple tests with a IAT sensor, thermometer, and some hot water.

Lastly, configure the software (Xv = X*) and then wala, i can datalog my IAT readings

I was also told that the IAT sensor's thermistor isn't a linear curve but linear at first and then curves at the end. I am not worried about this, it will be close enough for my purpose

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Craig, since only the TPS and the MAP receive the 5v source...you think it would be ok to tap into that 5v supply for 2 more sensors? I mean i dont think the load could be that great

thanks for your help

edit: As you already know, The IAT has its own signal coming from the ECM. I just looked at my modified pin_out list (i installed a single 48pin bulkhead connector to clean up wiring and had to make one) and looked and confirmed what you told me.

here is a nice link to the specs on the GM IAT sensor:
http://forum.aempower.com/bbs/download.php?id=312

 

[DOHC Vobra]

Nice tech specs for the IAT! Any chance you have a link to one for the GM 2 bar map sensor???

BTW, i'd be carefull hanging anything extra off of the Sensor +5V...that stuff all seems to be VERY sensative to extra load and voltage draw on it...

How's about just putting a simple +5v regulator where you need the power, and run a standard +12v wire to the reg??? It'd be cheap and simple...

Thanks!
Justin

 

[TwinTurboIroc]

Originally posted by DOHC Vobra
Nice tech specs for the IAT! Any chance you have a link to one for the GM 2 bar map sensor???

BTW, i'd be carefull hanging anything extra off of the Sensor +5V...that stuff all seems to be VERY sensative to extra load and voltage draw on it...

How's about just putting a simple +5v regulator where you need the power, and run a standard +12v wire to the reg??? It'd be cheap and simple...

Thanks!
Justin

check out www.aempower.com and go to the forums.....maybe they'll have the GM 2 bar there

I know i could just get a 5v regulator....no bigge. Just extra stuff i just wanted to make it a little cleaner ya know