- Location
- West Jordan
So, any electrical geniuses on here?
Here is what I want to do. The OM617 is turned off by vacuum. I would like to have the vacuum pump turn on for about 20 seconds after I turn off the ignition switch and apply vacuum to the injection pump of the OM617. I guess there is probably a relay out there that could do this. The power on my trucks accessories turns off after I open the door. If I could do something similar, that switches on after the ignition is shut off. Any ideas?
So, does the injection pump shut off when vacuum is applied, or when vacuum is removed? I'd assume it shuts off when the vacuum is removed...? If this is the case, what will leaving the vacuum pump energized accomplish for you? Do you want the engine to run for 20 seconds after you turn the key off?
I think a time-delay relay could accomplish what you're asking for, but I'm not sure if you can find one that will work for a 20 second delay. More components may be required for a delay that long:
http://www.allaboutcircuits.com/textbook/digital/chpt-5/time-delay-relays/
Any reason you can't just tie the v-pump into power (via a simple SPST relay) that is on the door-open-delay accessory circuit?