XFI voltage?

[tom j]

I noticed when monitoring the car idling, that the voltage was 11v and when I turned the fan on it jumped upto 12.5v. Is this normal for the xfi to read lower than the alternator output. I know I have to look into why the voltage increases when I turn the fan on not off.

 

[WSLN 6]

Sounds low to me, you might have to start tracing wiring fomr the alternator to the starter and back to the ecm to see where the voltage drop is coming form. Mine is 13.7 at idle (14.4 alternator) and 13.3 at WOT.

 

[tom j]

How much voltage drop should I expect compared to the pin out and what the xfi says(computer screen)?

 

[Boost231]

On mine its low as well. I will have 14 volts all the way to the caspers adapter box. Then after the box I only get high 12's. O well I guess. Doesn't hurt anything

 

[Reggie West]

Make sure the XFI sees at least 12 volts or better under any kind of load. If it gets lower than that the ECM does not work well and you will get some strange readings. It wont drive the injectors properly either so it screws up everything.

Check a datalog to see what it is reading.

The volt booster is a good fix if you need it.