u/SwimmingSir8027

Hi,

I have a strange issue and i hit a wall and cannot solve, need help:

I installed a 12V DC landscape lighting system (10 LED fixtures). Power is supplied by a 60W DEWENWILS transformer (also tested a 100W unit from another brand). When the lights are ON, my garage door remote range drops from 300+ ft to ~50 ft, and the door randomly opens on its own at night.

What I've tested:

• Lights OFF → remote works fine (300+ ft)
• 2 LEDs only → works fine (~250 ft, no random openings)
• 4 LEDs → range drops to ~30-50 ft, random openings occur
• 6+ LEDs → remote barely works, random openings continue
• All 10 LEDs → nothing works!
• Installed ferrite cores on the 12V output and each branch → no change
• Extended the opener's antenna using coax (center conductor exposed, shield grounded) → range improved slightly, but random openings persist
• Swapped transformer (60W → 100W, different brand) → no change

The issue:
The problem seems to scale with the number of LEDs connected. The random opening is the main concern—I can live with reduced range, but I cannot have the door opening by itself.

Goal:
I need to stop the random openings without replacing the entire system. I'm open to suggestions.

Setup:

• Opener: LiftMaster/Chamberlain (rolling code, 315/390 MHz)
• Transformer: 60W 12V DC (DEWENWILS) / 100W DC (other brand)
• LEDs: Standard 12V landscape spotlights (integrated driver) (Aiwewin 12 Pack 6W Landscape Lighting - B0CNK5435Y)
• Location: Lights are mounted on exterior walls and soffits, surrounding the garage on 3 sides

Thanks...