Automotive relays have built in back emf protection diodes.
Comment on Is there such a thing as an automotive relay with no resistor?
drspod@lemmy.ml 2 months ago
You need to find a schematic for your car’s electronics in order to get a proper solution for what you’re trying to do. I would be particularly cautious about connecting a relay coil to some unknown wiring. The back e.m.f. from a discharging relay coil could easily fry a microcontroller if it happens to be connected to one.
SmoothIsFast@lemmy.world 2 months ago
cvieira@lemmy.ml 2 months ago
I’m confident the wire I’ve tapped into is the horn, since I’ve previously used it to install a horn override as part of a PA system. That being said, I hadn’t considered that I might be connecting to a computer rather than something more analog. When I press the horn, I can faintly hear a relay clicking in the engine bay, so I’m hoping it’s just a simple relay.