Hondata

Hi guys,

I'm in the midst of making my own K-swap harness using the Hondata schematic. I just have one question with supplying power to pin#30 on the A/F Sensor relay.

The Hondata diagram shows pin30 with switched Ignition power with a side note: "Do not supply the O2 sensor heater relay with unswitched 12V. It must be a switched power source. Otherwise the relay will latch on and never switch off, so your battery will go flat quickly and the O2 sensor will burn out."

But I noted in the RSX service manual the factory wiring has un-switched 12v via Under-hood fusebox Option 30a fuse into under-dash fusebox 20a fuse (Hot at all times).
I was hoping to also use my unswitched Option +B connector in the EK under-dash fusebox as the power source

With the RSX the coil side is switched from the ignition key and the power side constant. However, if you wire it up for an engine swap and use the main relay output on the coil side then it will latch on and the o2 sensor never powers off. There's no disadvantage using switched power for both the coil side and power side of the relay.