I installed my UTEC Weds night, all went very well.. I installed the Tuner Wideband, but am having a problem figuring out where to get power from...

The wideband has the db12 cable which says that is what powers the tuner, so my question is what should I 'tap' into to get power??

The db12 cable has the 1 cable for the o2 sensor, another for testing or ?? and another with exposed wiring which are red and white.. I assume that this is power/ground..

Thanks for any input!

 

On my G, I tapped into the alternate power source next to the glove box.. Its NOT always on which I did not know.. It works well.. I can post pics later..

 

I'd like to hear more input on this. KenK2: How has the acc power worked out for the TunerXS? I read in the manual that the switched 12v is a very dirty signal (confirmed by my GTech's instruction to use this 12v as the best source to pick up ignition noise used to compute rpms). Has it worked out ok for you?

Where have other folks grabbed a switched 12v and ground for the TXS? I haven't gotten down in there yet... I'm thinking I may just ground on a nearby bolt, and then run 12v to the fuse box and just make it easy on myself (and my switched 12v harness).

Thx
-Smoky

 

i just added a fuse, with a add-a-fuse, it plugs into the kick panel fuse box and has a little whip off of it...


in the fuse box, it says if it is 12v constant, switched ACC, or start power...


grab the switched ACC...

 

Jeremy told me to do this and it is probably the logical smarter way to do it. I was lazy and wanted to get my utec/tuner going.. I will probably change it over sometime in the newar future..

It does seem to be working fine tapped into the alternate power source.. I plg the laptop power into it too and it works just fine..

 

Anyone know how many amps the tuner draws? The manual doesn't mention it. I would think it must draw at least 10a since it powers the O2 sensor heater... Knowing this would be a big n choosing which fuse to borrow.

 

BTW the wiring on my DB15 is:

4 plug for Bosch O2
2 plug for (I assume) VW O2 (or testing, as you suggest Ken)
1 blue wire, stripped end
1 white wire, stripped end

I assume white is 12v and blue is ground? Funny that Ken's is Red (as one would expect).

 

Blue is hot, white is ground..

 

I would think a 20a fuse would be sufficient.. At least that is what I am going to use..

 

So which fuse from the box would be good to share then? Which one in the box has a 20a rating that isn't already being used?

Apologies...I know about circuits and elec. safety but I don't know much about the Z's electrical system (and the shop manual doesn't make it ez).

 

Go to AutoZone or Checker or whatever and get the add-a-fuse.. the one with 1 wire..

 

Right, but even if you add a 20a after a 5a or 10a then you're not really safe. That 10a circuit wasn't meant to supply a 20a circuit (though I know we're using 20a as a safe measure).

I'm actually liking the idea of using a relay. Fused power coming from the battery, then switch the relay using a switched ignition source. Since you are just powering the relay then you could even use the acc fuse for that.

It's an extra wire through the firewall, but it is probably the safest way to do it. I'll dig around the fuse box and see what is offered. But I tend to think any of the bigger fuses are there because they are already loaded up (a/c, etc.).

This is all assuming the Tuna doesn't have some magic capacitor or ballast inside it that turns water into wine, and can power that O2 heater without popping acc fuses.

 

You don't tap off the load size of an existing fuse, that would be wrong, whether it's a 5, 10, or 20A circuit. You want to tap off upstream or the battery side of the fuses. Then your circuit is the only one fused and protected by whatever you choose (20A in this case).

 

Well, you can tap based on the load size if you know everything else going into the tapped fuse and know that your new device does not exceed capacity of the circuit.

I decided to just use a Bosch Relay anyway. Then I can run an separate inline fuse for that 12v, and then just tap any switched source in the area for the relay. Then there is no running wires over to the fusebox at all, only one through the firewall grommit.

 

Reviving an old thread to see if anyone tapped the fuel pump relay for power for the tuner/O2 sensor. This is to prevent the O2 sensor (and heater) from being powered all the time when the ignition is on and prevent sensor shock (cold water vapor hitting a hot sensor). The fuel pump relay is only on for 1.5 secs when the ignition is on but the car is not started (FYI).

For those of you that didn't do this, have you had any problems with O2 sensors failing?

 

The fuel pump relay works great. Only turns on when motor is actually running (not just ignition on), which is exactly what you want for an O2 sensor. You can access it behind the battery (IPDM black box). It's the 2nd relay down on the far right, center pin (modified a fuse tap to access power there).