Hello, I usually don't get involved when another expert is but I have read this and previous posts for the problem you are having, I have seen this problem a few times on this year model Corolla. Replacing the DRL relays will not correct this and will just burn out the new relays, the real problem is a loss of ground which increases resistance in the circuit and this causes the DRL relay to burn out, there are two relays, one under the hood and the main relay under the dash above the glove compartment.This relay has to be replaced but not until the cause is fixed.
Look at the fuse panel on the lower left of the dash where the fuses are, there are several connector going to it, check each connector's wires for signs of overheating, usually it's the brown/black ground wires, there is a ground bus connector under the dash on the left,it may be taped to the main harness, it has a bunch of white/black ground wires going into it with a terminating conector on the end, these wires may appear burned and discolored,
remove the connector plug on the end, you will most likely a lot of corrosion inside, this is the problem. This is a ground distribution point, it has a couple of ground wires coming in which supplies ground to the rest of the wires. What I have done a few times is to just wire a new ground connection bypassing the original, once all those white black wires are grounded the problem is solved.
Again, I normally don't jump in when someone else is involved but you don't seem to be getting anywhere with the answers you are getting so I hope this helps, if I'm wrong you don't have to accept and you can relist.
Thanks for the reply. The DRL (main) is the one behind the glove box, did you locate the connector under the dash that has all the white/black wires going to it and is it in good condition, no overheating or corrosion?
I won;t be able to get back until later this afternoon, I have an appointment to keep. I'll take a look at the wiring diagram later but just wanted to make sure those ground connections are intact.
That's what i was afraid of, I think the problem is internal to the junction block where the relays and fuses are, there is an integration relay on this junction block as well, I would try replacing the entire junction block/integration relay unit.