Proper Diode?

Hi, Need help selecting a proper diode. Tapping into preexisting separate 10A and 30A fuses, each operating separately and not at the same time, combining them to power 4 separate side marker bulbs. I'm concerned about the feedback when the constant lights switching between the 10A and 30A fuses. Individually, each bulb has a power draw of 69mA/0.89w. Combined, the four bulbs have a power draw of 276mA/3.56w. Thought about just using a 1N4004 or 1N4003 diode. Thoughts?

I would use two SPDT relays instead of diodes. Relay One 87 to 12V+ (fused at battery, accessory, or ignition depending on your needs) 85 to 12V+ from 10 amp fuse 86 to ground 30 to terminal 87a of relay two Relay Two 87a to terminal 30 of relay one 87 to 12V+ (fused at battery, accessory, or ignition depending on your needs) 85 to 12V+ from 30 amp fuse 96 to ground 30 to marker lights positive Anytime you have power from the 10 amp fuse or the 30 amp fuse, the marker lights will have power and both fused circuits will remain isolated. the12volt • Support the12volt.com

Adding two relays would make sense; however, a diode to prevent feedback is also practical in this application as well. Thoughts on the diode?

The bits I'm not really passing along is that I am not adding an accessory, simply substituting the current way the sidemarkers are ran. I'm choosing the spike/feedback suppression only as an overly cautious precaution.

Either of the diodes you listed will work, but you will need two with the cathode ends tied together at the lights and each anode end toward each power source. The reason I suggest the relays versus the diodes is to maintain complete circuit isolation which would be the most "overly cautious precaution." the12volt • Support the12volt.com