fuel pump kill using wiper switch

i wouldn't go with the adapter. you could have a friend or child pull it out on you while driving not knowing what they are doing.. the stalk switch chould be ok presuming its not too easy to knock off by accident. Why oh Why didn't i take the blue pill

Darren Power

Wire up the relay in latching configuration and it won't be affected by any accidental unplugging while driving. The wiper switch/cig plug etc. only has to work once when starting; after the relay is energized, they won't have any other effect. All you need is a diode to keep the coil energized, and it'll remain on until the car is switched off from the ignition. Also, make sure your switched trigger signal turns off when you shut down the car, or else the relay will drain your battery down while parked..

Can I also use the fuel pump power line for the wiper switch?

nice one dual.. thats the best way to go alright.Why oh Why didn't i take the blue pill

Darren Power

Ahh, I think I follow, it looks like you have the relay continuously re-activating the trigger using the output, that's pretty slick. Thanks for the detailed info!

Important thing is to get a quality relay for this; because you definitely don't want any failures while driving.. This is something I just thought of, which I'm not sure might be better or worse for reliability, but you could put a resistor in line with the D1 feedback diode, to drop the amount of current used in maintaining the relay in the closed position. That would make it easier on the relay by reducing the power going through the coil for the long periods you're driving; relays generally need less power to hold it closed after the initial closure. You'd have to check the specs on your relay to see how much you could reduce it, based on the hold voltage and coil resistance. I'd also suggest putting in a backup mechanical switch in a buried/hidden location which you can switch in just in case you do experience a failure- if it happens on the road, it'd be a lot easier flicking a switch than trying an on the road splice/bypass...