holyspatulaboy

I am trying to find a place where i can get aprox .2 amps or less but only when the engine is running... not when it is in accessory but when the engine is actually running. what i am trying to do is set up a relay system that engages only when alternator is producing power.

shawnvw

What exactly are you trying to produce? Anytime the engine is running, the alternator is producing power. It produces more in times when demand is higher.
you can get .1amps directly at the battery if you wanted. Amp draw depends on the load that is placed on the power source.
If I knew what you were trying to achieve i may be of more help.

If you are looking for power only when the engine is running, you might try to tap into the fuel pump circuit. Although there is a 2 second prime before the engine starts, it will shut off when the engine is shut off

holyspatulaboy

Sounds great ill have to check it out... what i am doing is building a distribution box that only distributes power when the engine is running, to prevent battery drain while in accessory. its more of a safety feature than anything. i might even turn it into a dual battery install eventually so i can jump start the truck from a spare battery using a momentary button inside and a 200 amp contactor and only have it connected while the engine is running orif the momentary button is contacted.

Should i pull it from the relay or the fuse. and if i pull from the relay should i pull from the contact side or the control side. im using a 1 amp micro relay so its not pulling anything really.

my origonal plan was to pull from the ignition system but could not find a good wire to tap but i like the fuel pump idea better

Thanks you very much ill post if it all works out as planned.

jmack91z28

Why are you trying to prevent battery drain when in accesory? For a sound system or something?

holyspatulaboy

I have a high amp draw C.B. i have a tendency to kill thebatterywhen im drinking.. this will help me drive home in the morning when i wake up./ ill forget my head lights on when im working on something in teh dark.

shawnvw

I would go to the relay itself as the fuse may or may not be B+ or IGN.....the relay will give you the power at the time you need. I would put your micro relay into the control side of the relay....of course with 1 or 2 amp fuse in case something should happen you won't get stranded

holyspatulaboy

thank you i am going to start the project as soon as i get back from my trip to alabama...ill post results when its complete

jmack91z28

I don't know if your already doing this but it would be best to maybe mount the relay inside the cab. I had an aftermarket fan relay system I put on for someone before and the relay went bad from being in the engine compartment. I'm just saying cause I'd hate to see your great work go bad from a little ice cube relay burning up. Good luck to you, and just for the hell of it, how much current does the C.B. draw cause i'm thinking of getting one too.

northey87