Printer Friendly Forum Posts - Relay Wiring For Pulsed Ground, MP3 Headlight Chime

i am working on a project trying to solve a challenge when installing a vw headlight switch into a streetrod - seems that if ignition on the car is shut off and the light switch is on , the headlights shut off but the parking lights stay on ( i have verified this is normal behavior for these switches).

so my thought was i needed to generate a chime to remind me to shut off the light switch

initially i was going to use a basic chime and i found a relay setup that would output a ground when i turned off the lights

86 is ACC 12V+
85 and 87a grounded to car
30 goes to the chime (-)
and the positive 12V+ from the parking lights goes to the positive of the chime.

This worked fine for a basic 2 wire chime

However..

further experimentation and searching the net, led me towards a module (instead of a basic chime) that would allow me to send a pulsed ground trigger, to start an mp3 file to use as my chime. I dont think the above chime example will work as i think it outputs a constant (latching)? ground. and this module prefers a ground pulse to trigger

i found the following relay example on the site https://www.the12volt.com/relays/relaydiagram43.html

but i dont know if its the right choice and I don't have any experience messing with capacitors / resistors so i'm a bit clueless on what to buy or how to wire it (don't want to wire something backwards etc)

so hoping someone here can provide some guidance so i don't screw this up

- is this the right relay example to use ? ignition is off, yet power still coming out of parking light wires. would like to create a pulsed ground from this scenario somehow
- what do i buy for cap / resistor
- can this things be wired incorrectly (ie - backwards).
- anything i may be overlooking?

Thanks for any help