Random Flashing Headlights

Hello, I am new to the forum but excited to be here and looking for any help/advice I can receive and hope to be able to reciprocate when possible. I have a 2002 Toyota Corolla. The issue I have been having is that the headlamps and tail lamps are flashing randomly. They flash for about 10 seconds then stop for about 30 seconds then flash again. There is also a clicking sound(similar to the one made when the hazards are on) heard from the inside. I know it is not the hazards because when I turn the hazards on their is another, separate clicking noise made and the flashing lights are brighter. I have attempted to reset the computer, pull out and put back in all fuses to no avail. Any help with this issue would be greatly appreciated. I would be happy to clarify any foggy or missing details if needed. Thank you in advance.

Sounds like an alarm to me. Does your Corolla have a factory alarm that maybe has a bad horn output, or an aftermarket alarm by chance?

This is most likely the circuit breaker for the head light / tail light circuit cycling. If the breaker is cycling that means you have a short circuit somewhere. If you have an added trailer electrical hook up, check the wiring for a rub through or grounding. If not, you will have to inspect each corner light housing for wiring problems. It might be a short in the wring to or the combination switch on the steering column.

You will shortly find out why auto electrical repair costs so much.

There is only 3 relays in the headlight circuit, Headlight, DRL and dimmer. Pull them on at a time until the clicking stops. It is either a faulty relay, faulty connection to the relay coil or what is driving that coil is faulty.

Shadowfax, I do not believe it has an alarm. It is a very basic model with manual everything.

Researcher, I do not have an added trailer hookup so I hope that rules that out. I recently replaced the brake light switch plug, which is near that whole steering column area. Is it possible that I interfered with anything down there that would cause this? I am more than willing to check each corner light to remedy the problem. How would able be able to tell if there are problems with the wiring?

knfenimore, if there is something faulty with one of those relays, is that something I can do myself and if not would it be costly to have it done? Thank you for the pictures, very helpful.

Shadowfax, I was actually mistaken. My car does have an aftermarket alarm. How should I proceed?

I stand corrected. I don’t see any circuit breaker in the circuit diagram. It may be something with the Day Light Running ligtht relay circuitry. No more help here. Sorry

Depends on what alarm it has. The trouble with aftermarket alarms is that there are a lot of them, and they aren’t always, or even often, installed very well.

Do you still have the key fobs for the alarm?

Otherwise, try to determine what kind of alarm it has. If you don’t have documentation, try looking under the dash behind the radio - that’s where a lot of installers put the central alarm module, which should have a label on it telling you what brand.

Most of them have various tricks you can do to turn the alarm off without having a key fob, such as cycling the key from off to on 5 times rapidly.

I was not given any key fobs for the alarm. Once I locate it, is there a way I can remove it so I no longer have to worry about it?

Since you have an aftermarket alarm, that would be the first suspect. Before considering other possibilities, suggest to rule that one out first. You’re going to have to find out what kind of alarm it is, who the manufacturer is. That’s probably the first task.

If you feel lucky, you could have a quick look-see down in the area where you were replacing that brake switch connector. You might spot something that has come disconnected.

I will definitely try that first. If it is the alarm, would that be very difficult to remove?

see if it has a fuze you can pull.

This is what my switch looks like, it is after market right?


Bad aftermafket imho. REALLY?

Do they only flash in Auto mode or can you turn them on manually and they work? The relays are either under the dash or under the hood. I would look for the clicking relay and replace it. They pull right out of the fuse block. You can swap it with another relay in the fuse panel that has the same part number printed on it.