would the keypad be able to switch on the PDM and ECU? (Haltech)

Hi,

currently im planning a wiring diagram for a friend's car and I was wondering if an ignition switch is necessary to turn on the PDM and ecu or if the can bus keypad have the ability to wake up the ecu and pdm?

another thing is we are planning to install a kill switch on the back of the car but the battery in front of the car, so I'm thinking instead of running the battery cable all the way back, I would just connect the ignition input wires from the ecu and pdm to the kill switch and just kill the signal? or should I use the kill switch function in Haltech ECU instead of the ignition input?

does it matter if I connect both the ecu and pdm into ignition switch or if I use the ignition power output from pdm into the ecu to wake it up

Fahad,

For the keypad to turn other things on via the PDM, both the PDM and keypad would have to have power, otherwise pushing the keypad button wouldn't do anything.

A keypad at rest doesn't use a lot of current, nor does a PDM that's only powering a single keypad, so that can work for turning ignition on, but generally you'd also want something that can actually shut the whole vehicle down to avoid draining the battery when the vehicle is going to sit off for more than a few hours.

I usually have a master on/off latching button wired to a battery isolator system which is also a key safety feature.

Alternatively you can use a big main battery cutoff switch.

Either way, turning master power on would power the pdm, which would only power the keypad, until you push the keypad button to turn ignition power on.

Hopefully that explanation makes sense. If not please let me know.