Wideband Wiring

[brsvo]

What have you guys done as far as entry to the vihicle with the wideband wires? I am leaning towards the shifter boot, what are your thoughts, Bruce

[caroth]

I bring the gauge wires in at the grommet next to the clutch cable or speedo cable. O2 signal and power wires are all under hood to keep the noise as low as possible.

[Bob Holmes]

I drill a hole on the tunnel (near the cigarette lighter on an SVO) and wire it up to the lighter's power and ground. The wiring is run through a grommet. Nothing is seen without removal of the center console.

[MikeFleming]

There is already a nice-sized tunnel hole on the drivers side fo the forward tunnel area - where the backup lamp switch wiring goes.

[brsvo]

Thanks all great idea's. I want to put a gauge in the car. The pillar pod or behind the steering wheel seem to be the place so there is more routing than just the signal and power. What is this noise you were talking about?

[MikeFleming]

Electrical The wideband O2 signal is a very low level signal, like in the 0.01-1.1 VDC. So any slight variations in the 12.6-14.0 VDC supply and (associated grounds) can be significant.

[brsvo]

All the wires go to the gauge as this is apparently the controller. Then back to the computer so where is the least noise from my A pillar to the computer and from the sensor to pod? I thought bringing it in the cabin as quickly as possible was the right thing to do am I wrong? Also does anyone run the AEM 30-4100? How bright are these gauges? My fuel pressure gauge is rude bright and I may just replace it with this on the column. If I do that then I will leave the narrow band gauge in the pillar. Thoughts?

[Raven855]

I see you have been posting on Stingers site too, so you are aware of calibrating issues that some times happens. The MS site has lots of stuff in this regards. If you are using the Pimp with Megatune you can do some calibration. Caroth mentioned some noise potential. There are certain areas of the engine bay that are electrically noisey The injectors, distributor, alternator, ISC and EGR areas can cause trouble. Here are some general guidelines from AEM:
"Grounding
The ECU must have an electrically secure ground connection, which means that the battery negative must be properly grounded to the chassis AND engine. The ground wire, whether it is from the battery or to the chassis and engine, must have perfect electrical conductivity. This means that there must not be any paint or rust under the wire terminal. Make sure that when you install the ground wire there is bare metal exposed where the wire contacts the vehicle component. To prevent rust build up, we recommend applying a protective layer of dielectric grease, such as Standard Ignition SL-4, to the bare metal surface. The ground wire must be at least the same gauge as the power lead to the ECU. We also recommend that the ground wire be as short as possible.
Power Requirements of the AEM EMS
The AEM EMS requires a minimum supply voltage of 10V or greater to run. We recommend that the ECU be supplied with 13.8V nominal operating voltage. Ensure that the vehicle‟s charging system is in perfect operating condition prior to installing the AEM EMS."
My experience with the AEM is that the cleaner the power to the unit at the 13.8V the better your results.

[brsvo]

Yes I am reading and trying to keep it all straight. I like the power off the lighter as its easy to find and the ground according to AEM could go to the PIMP/ factory ECU ground? Will the radio cause noise (yah dumb question but) It would seem simplest and shortest to route all the wires past the radio to the ECU? Also I want to run the gauge all the time so I hook up the analog wire so I can disconnect while not tuning correct?

[Raven855]

Power and grounding is one area that I find suspect even with the stock system. The circuit to the ECU has 14G wires of supply and grounds that I feel undersized to begin with. If you look at the grounding system from the ECU to the battery it is not direct. From memory, you have a couple of taps and that body ground under the battery that is subjected to the engine compartment heat, vibration, weather and battery acid. The supply does not go directly to the ECU either. It supplies, what 5 to 7 other circuits, including the fuel pumps and injectors. If you have the stock alternator there can be conditions where you may find that you are discharging at times. I will have to look at the wiring diagrams, but isn't the lighter only a 16-18G wire and on all the time? Do you have a 3G alternator?

[brsvo]

Yes I have a 3G. Don't know about the lighter as I don't smoke! Can't really do a dedicated power because it needs to be switched. But maybe a dedicated line for ground?

[MikeFleming]

Methink everyone should own and drive - at least one time in their lives - a gfrp (fiberglass) car. Where every electrical item has both a power and a ground wire going to to it. Not relying on chassis ground screws.

I don't like the concept of using the chassis as the electrical ground. Just doesn't sit right with me. Where problems can be intermittent and difficult to troubleshoot especially when electronics are involved. Getting it right is hard.