Engine kill and enable strategy

Hi,

I am busy trying to decide which way to go with my engine run and kill strategy.

I am also using a PDM that I intend to kill power to to then stop providing power to injectors and ignition.

I intend on leaving the alternator connected to the battery at all times to help with load dump..

I have attached a picture of 2 scenarios:

The first is where the kill switches link the earth to activate the relay to provide power to the Pdm. There is also another switch that has to provide power to the input Pin on the Pdm to make it live which I will call enable mode where the injectors and ignition are not powered.

Now with the second I want to eliminate the enable switch.. The reason being I might as well make this auto enable when kill switches are closed...

Anyone see any issues with this?

Hello Karl,

Looking at your diagram, it appears you're trying to achieve the same function as an ignition switch, rather than a battery isolator, right? Also, in the diagram you have the relay output going to the centre of the PDM. Is that the PDM 12V input stud being powered through the relay?

I was thinking that I would isolate the battery from the Pdm to kill the engine whilst leaving the alternator connected to the battery... I guess though that eliminating the relay altogether and just using the kill switches to remove the ign power to the Pdm would do the same thing to shut off power to the ign and injectors?

Yeah, that would be like an ignition switch, switching off the engine. You would have to check your rule book for the motorsport you want to compete in, as this set up would not pass for a battery isolator in most cases.