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Does anyone see a problem with this? I have my wideband powered directly off the battery with a switch in-line that I use to turn the wideband on and off. I figured this would reduce any voltage step issues, but wanted to get everyone else's input.
Thanks
I'd probably use a relay instead of a switch. If you forget to flip the switch you will ruin your sensor.
Not sure that you would ruin the sensor unless you have a really crappy wideband but you might end up with a dead battery.
I'm just going by what it says in the manual that came with my NGK Powerdex AFX wideband kit:Quote:
Originally Posted by EC_Tune
"The power terminal (RED wire) should have 11 to 28V DC attached (via a switch or relay) whenever the engine is running. If the sensor is not powered when the engine is running, sensor life will be shortened."
So I guess it won't ruin it immediately but will shorten it's life. Maybe this isn't true for all sensors. The AFX kit is can use either the bosch or NTK sensors so I believe it is true for both of these sensors.
I use the AFX controller with an NTK sensor and I power it by directly off of the battery. While configuring the table, I may leave the wideband on for a while with the car off. I have not had a wideband fail by this use, but I now unplug it to spare the vehicle battery from the extra load. :) It is perfectly safe to wire the controller to the battery for tunign purposes. If it will be a permanent istanl, the you will need to wire it to an ignition source or have it powered off of the battery with a relay from an ignition source.
Thanks for the help guys. I have actually be running around this way for ~3 months. I mounted my switch right beside my ignition switch and its engrained in muscle memory to turn it on before driving and off after shutting the car down. I will eventually wire in a relay, but the autoparts only had your basic switches when I was installing it.
I did it this way to avoid voltage variation so I could match the HPT interface and the wideband with the car in auxilary mode. I know when these cars are wired off of switched sources, the voltage varies from ign. to auxilary. I figured battery voltage would be constant regardless.
"The power terminal (RED wire) should have 11 to 28V DC attached (via a switch or relay) whenever the engine is running. If the sensor is not powered when the engine is running, sensor life will be shortened."
what that says is running without the heater will shorten life.it does not say that heating without running will shorten life.
I have an AFX also. Since we are on the subject of instructions in the AFX manual. What about the part that says you should connect the signal ground (brown wire) to the same location as the main ground (2 black wires)? I was planning on running the 2 black wires to the battery (-). I would like to run the signal ground to the MPVI interface. How can I guarantee I wont end up with a voltage offset?
Thanks!
I connected my signal ground to the MPVI EIO plug. I didn't remember reading that part of the manual.....maybe it was revised after I bought mine. Either way, it doesn't "appear" I am having any issues with the way I have it connected right now. The w/b has been very repeatable and with the help of a buddy, we picked up 10whp/8wtq across the board over my previous tune from a shop.
OK, cool. Thanks for the feedback.
Here is where I read it. Page 10, rev6 of the manual, specifically point #2. But 1 and 3 are related.
AFX Wiring Notes
1. The AFX considers the point where the two BLACK wires connect to their
ground as the 0 (zero) volt reference point.
2. When utilizing the analog output feature of the AFX, always be sure to connect
the system ground (two BLACK wires) to the same location as the analog
SIGNAL GROUND (BROWN wire). The analog output wires (YELLOW,
BROWN) may be lengthened as long as the appropriate gauge wire is used and
the connection is solid.
3. It is advised to connect the BLACK wires directly to battery ground or as close to
this point as possible. Do not extend the two BLACK wires using a single wire or
else this can cause a shift in the ground level of the analog output SIGNAL
GROUND (BROWN wire) and any device linked to the analog output (data
acquisition or engine controller) will receive an incorrect signal.
I assume it would also be safe to sink the 2 black system grounds to the MPVI also? I forget what the absorption capacity of the MPVI is off the top of my head. But the AFX only uses 2amps during normal operation, 3.5amps during warmup. Maybe someone can confirm the capacity of the MPVI?