I'm at a complete loss as to what is going on. I have a '13 RAV4 and the headlamps are immaculate at least on the exterior. No hazing, fogging, none of that. I put in some Philips 9011s and the low-beam performance was great. They were the best lights I had ever sat behind. I left the car sitting for a few months, and when I returned to it, the lights are beyond dim. I had to pull over and check the bulbs on the side of the highway several times to make sure they weren't actually burned out--that was how bad it was. I installed a relay harness I had pulled from another car on the side of the highway too and it helped somewhat.
Now, I've already tested for the obvious stuff. The battery is fresh, it read at about 12.6 volts with the car off. With the car running, I'm getting about 13.6 volts across the battery terminals. I'm using a relay harness, and when I measure the voltage at the ends of the harness, I'm also getting about 13.6 volts with the car running. I took the car to the dealership for a check of the electrical system. Everything checks out. I inspected the bulbs. The capsule is clear, with no hazing. The filaments look fine--there's nothing obviously out of alignment or damaged. The bulbs are firmly seated in place.
I feel that I've checked everything. I've checked the condition of the headlamp lens, the bulbs, the voltage at multiple locations, and everything checks out. The one thing that remains is the condition of the reflectors inside the lamps. The car has low-beam projectors and I obviously can't inspect the reflector bowl. That's the only thing that I can think of. Could the lamps be toast on the inside? Is there a way I can test? Perhaps the most conclusive test would be buying a new, OEM headlamp assembly and testing the old and new assemblies side by side...but I'd rather not perform such an expensive experiment. Perhaps I should try new bulbs first? But why would bulbs that look perfectly fine be underperforming?
Now, I've already tested for the obvious stuff. The battery is fresh, it read at about 12.6 volts with the car off. With the car running, I'm getting about 13.6 volts across the battery terminals. I'm using a relay harness, and when I measure the voltage at the ends of the harness, I'm also getting about 13.6 volts with the car running. I took the car to the dealership for a check of the electrical system. Everything checks out. I inspected the bulbs. The capsule is clear, with no hazing. The filaments look fine--there's nothing obviously out of alignment or damaged. The bulbs are firmly seated in place.
I feel that I've checked everything. I've checked the condition of the headlamp lens, the bulbs, the voltage at multiple locations, and everything checks out. The one thing that remains is the condition of the reflectors inside the lamps. The car has low-beam projectors and I obviously can't inspect the reflector bowl. That's the only thing that I can think of. Could the lamps be toast on the inside? Is there a way I can test? Perhaps the most conclusive test would be buying a new, OEM headlamp assembly and testing the old and new assemblies side by side...but I'd rather not perform such an expensive experiment. Perhaps I should try new bulbs first? But why would bulbs that look perfectly fine be underperforming?