Toyota Repair: 1997 Camry headlights turning on by themselves, fuse block, timed delay

Question
QUESTION: Hi,

I'm having trouble with the headlights on my 1997 Camry
turning on by themselves, often in the middle of the night.

This starting happening last October. After reading some
online about this problem I suspected the headlight relay,
because the tail lights don't go on with the headlights and
turning the headlight switch has no effect after the lights
have turned on by themselves (until I start the car, after
which I can use the switch to turn the headlights off).

So, I replaced the headlight relay this past November, and
the problem went away - until 2 weeks ago, when it starting
happening again. I just ordered another new headlight relay
and installed it ... and not 2 days later the lights turned
on by themselves again with the new relay in.

Any ideas?

I really appreciate your help.

ANSWER: When the headlights turn on do the dome lights turn on as well? Does the car have the auto-off headlight feature, do the headlights normally turn off when the key is removed after a few seconds delay?

---------- FOLLOW-UP ----------

QUESTION: No, the dome lights do not turn on with the headlights. The
car has the "retained power" feature so that the headlights,
etc. turn off when you open one of the front doors (not a
timed delay). We usually just leave the headlight switch in
the on position, and they always turn off when we open the
door (but then sometimes turn themselves on later...)

Answer
The on/off function is controlled by an integration relay and there is a good chance tht it is the problem, this relay is located on the rear of the fuse block(junction block) on the lower left of the dash, it's the one that has all the fuses on it, some of the integration relays can be replaced seperately but in some cases they come only complete with the entire junction block, check with the dealer's parts department, replacing it is not that difficult, it just involves disconnecting all the attached electrical connectors and some relays annd transferring them over to the new part.