sorry to bring this thread WAAAAAY back, but is this information accurate?Brian said:theres a relay in the side panel, behind the drivers seat-where the left rear passanger armrest is . Take off the panel and there are 2 10mm nuts holding a bracket with 3 or 4 relays on it. Find the one that says headlight relay ,thats the one you'll need to replace. Toyota wants $110.00 for it so i'd advise a trip to the junkyard. I got mine out of a celica gts( Im sure a celica would work also). Try to get one out of a non-sunroof car as they tend to leak and kill the relay.
Hope this helps,
suffered with this problem for a year before i found a good relay