I am trying to figure out a way to trigger a buzzer to remind me when I leave my lights on. I have thought of a way that uses three relays and it may work fine, but I just want to make sure there aren't any better ways to do this. Basically I want the buzzer to sound when the lights are on, the Ignition is off and the door is open. Here is current idea:
Relay #1 85 - 12v+, 86 - to my door trigger, 30 to PIN 87 on Relay #2, and 87 to the Pos side of buzzer.
Relay #2 85 - Ground, 86 12v+ when Headlights on, 30 to PIN 87a on relay #3,
Relay#3 85 - Ground, 86 - Ignition, Pin 30 to 12v+,
The only problem I can see here is that if relay #3 ever failed the buzzer would sound when the lights were on and the door was open, regardless of wether or not the Ignition was on. Not a big deal at all, but I just wanted to check if there is a better easier or just different way to go about this.
I know about 10 years ago I bought a little buzzer kit that accomplished this same goal but it didnt even use a relay as far as I remeber. It was 10 years ago so I dont remember, but I went to checker and they didnt have anything like that. That is where I thought I bought it from 10 years ago. I think it was Big Wheel Rossi back then, or Champion, I dont remember.
Any suggestions are welcome.
i have seen these modules for sale in wal mart and other places, they usually dont acount for the door though.
I think you could do this with one relay:
85 - (+) Ignition
86 - ground
30 - (+) Headlights
87a - Output to positive side of buzzer
Negative side of buzzer to (-) door switch
I think that would work, check it out, just my idea...