I am wiring up 2x 55W Halogen lights and 2x 100W Halogen lights on my '01 Subaru Outback. I want all 4 lights to come on when I turn the switch on. I created the wiring diagram which I followed during the install (see attached pic) but ran into an issue:
As the system stands (following the diagram), with the engine off, only the middle two, 100W lights turn on.
I measured voltage at one of the 55W lights with the switch turned on, and measured only 0.5 VDC (working 100W lights had 11.8 VDC), which means that my understanding of how the relay works is flawed. It seems that I cannot use the circuit across the relay coil to power the smaller 55W lights. The 85-86 circuit is used for activating the relay, and cannot be used for other lights.
I noticed that adding a wire to connect the wires coming from relay terminals 87 and 85 produces the desired result (all lights come on), but those wires quickly get hot and the relay starts buzzing after about 1 minute of the lights being on. By my calculations, this would result in 310W/12V = 26A through the circuit, which is a lot for the smaller 14 AWG wires. I would have expected the 20A fuse to blow, but it did not. The relay is a 30A relay and neither the 15A nor the 20A fuses blew, so I do not think the relay was drawing too much current... any idea what was causing the buzzing?
- Why can I not use the relay (as drawn) to also drive the smaller 55W lights?
- What could be making the relay buzz when a wire is added between terminals 87 and 85?
- What can I change in my current setup to turn on all 4 lights without stressing circuit components?