12v when car running

[agithegreat]

Someone give me a cable that has 12v through it ONLY when the engine is running.
I tried the thin wire on the alternator... that was as useful as mudflaps on an airplane!
2.7 volts!!!

Cheers

 

[AlexG]

:S

 

[stooby]

cig lighter?
ignition on but not just the engine running..

 

[agithegreat]

I know i'm gna cry here.... I spent like an hour fitting a split charge relay. Then it just doesn't work. I followed exact instructions. But the ( sense wire?) just wont give me 12 volts+ like it's meant to ( or so i'm lead to believe )! (Is my alt balls up???)
Anywhere else you know of? I don't really want to charge the back batteryuntil the engien is running. Otherwise that defeats the object of a split charge.
cheers