I'm installing a defi BF oil pressure gauge. To avoid the oil temp warning when the key is in position 2, I need to find a power source that is on only when the engine is running. Any ideas?

I remember reading about this years ago on this forum, so I searched and searched but found nothing...

 

what do you mean by key position 2?

i did my boost and oil pressure over the weekend. i tapped on the blue wire with yellow stripe from the radio harness. gauges are on when the key is on accesorry and when car is running.

confirm on the wire colour. its in the how to section for defi gauges install

yoo heres the how to.

have fun.

http://www.evolution-8.com/howto/defi.php#defi5

 

Do you hear the oil pressure warning buzzer when the motor is not running with the key in the "on" position (key position 2)?

I want to connect the orange wire to a power source that only has the 12v when the car is running and not when the key is in the on position.

 

Just tried wiring it up according to this diagram in the link above.

Got the buzzing with the key in the "on" position. So back to my original question.

 

I got annoyed by the buzzer when the car was set to ACC and ON (with motor not running) so I installed a switch on the switched power source to the DEFI unit. Whenever I want, I flip the switch off and turn the whole unit off.

The other plus side is that when I go through security checkpoints or get pulled over, I can quickly turn them off and make the car a little more stealth to keep the attention down.

 

I know there is an AC wire somewhere that doesn't power until the engine is running. If I can't find it then a switch is the next best thing. Thanks

 

There is a switched "ON" source that won't have power until the key is in the "ON" position, but this will still cause the alarm to sound if the key is set to the ON position without turning over the motor.
If you are electrically inclined and want to avoid the manual switch configuration, you could use a relay on the alternator line and a relay on the ACC power to the DEFI control unit. The runing motor would turn the alternator, applying closing the relay, which would close the relay on the ACC power to the DEFI control unit. Not impossible to do, but would add complexitiy to something that is much easier to do with a simple SPST switch.
"The simpliest answer is often the best."

 

I like the alternator relay idea. I'll look into doing that if there's no better alternative.

True, but the best solution should simply work on it's own