Electrical Rf Shielding Sensor Wires

[DuderMcMerican]

Friends,

I have read about the importance of isolating engine sensor ground wires, and some suggested extra shielding to protect said wires from RF interference--particularly near the alternator and starter systems. How is this done? Is it as simple as wrapping those wires with aluminum foil and then tape-wrapping over the foil? If so, would one end of the foil wrap need to be grounded to chassis?

 

[mikestang63]

I use saran wrap personally

Honestly, what wires are you talking about wrapping in tin foil. Never heard of it. There is one RFI wire in the harness by the coil that comes prewrapped from the factory- that's it.

 

[jrichker]

If Ford didn't shield the wire it is because the computer, sensor and wiring were designed to ignore the noise. Unlike the digital signals, the analog signals don't change that quickly and are not as sensitive to the electronic noise.

The reading from the sensor network may have an electronic filter on the input. Actually MAF pins C & D float with reference to ground. The signal output of the MAF is a differential amplifier setup. Pins C & D both carry the output signal, but one pin's output is inverted from the other. The difference in signal between C & D is what the computer's input circuit is looking for. The difference in the two outputs helps cancel out electrical noise generated by the ignition system and other components. Since the noise will be of the same polarity, wave shape and magnitude, the differential input of the computer electronically subtracts it from the signal. Then it passes the signal on to an Analog to Digital converter section inside the computer's CPU chip.


Another approach to the same problem would be to have the computer to sample the analog signal at a specified time period and then do an average of the the sample results over several time periods. That effectively filters out the electrical noise. The ECT, ACT, EGR and TPS are analog sensors.

 

[jAEded]

Shielding is essentially a metal foil or mesh over the wires with the shielding portion connected to ground/negative. If its mesh then the hole size in the mesh depends on the specific size wavelength/frequency you're trying to block.

What issue are you having with your mustang that you believe RF shielding will alleviate?

 

[DuderMcMerican]

I use saran wrap personally

 

[DuderMcMerican]

What issue are you having with your mustang that you believe RF shielding will alleviate?

No issue that i think shielding will solve. I just have this problem where i read things on the internet and then assume that it is something i need to look into. I'm more than a little adhd. Haha.

Thanks a lot for your input, guys! I'll save the food wrap for sammiches.