I have searched and can't find anyone else doing this. I have a battery shutoff (negative) on my truck for safety and security. Since I don't drive daily, I shut the battery off during the week but want to maintain power to the PCM. From the pin outs I see an orange wire at Pin 20 and 57 - Battery Positive Voltage on the blue connector.

Do I splice into these two orange wires and run directly to the battery positive terminal?

Even tho I'm cutting off ground with the battery cutoff, is the PCM still grounded thru the harness ground?

Thank you very much.

 

Yes, when you kill your main ground, it'll kill the ecu as it sounds like the only ground path to your battery is through this switch.

 

I guess if I run the PCM ground direct to the battery it would be ok then?

 

The neg side for batt disconnect is not correct.

 

Bumping for more info. Looking in to doing this. My cut off (like most) is on the positive side.

 

Bump
Which pin should i connect constant power to in hopes of keeping pcm memory with battery disconnect hooked up. I spliced into pin 20 and 57 and put a fuse in-line but it blows the fuse every time the ignition switch is turned with the disconnect off. Any ideas?

 

Put a diode in line with the power coming from the vehicle, to prevent backfeeding.