The_Pied_Shadow

I've head trouble properly describing what's happening in a succinct way which may be why I haven't found a forum with someone describing the same problem. What's happening is my headlights sometimes just turn on and off when they are supposed to be down and off. Sometimes it's a flicker and sometimes they fully illuminate for a few seconds.

Here's a few clues I've found so far.

• When this happens the lights do not pop up and the high beam indicator in the instrument cluster does not illuminate. (This makes it hard to know it's happening during the day. I only notice it when I see the reflection of my car in someone's bumper when stopped at a light and see my headlights illuminated through the 'flash to pass' slots.)
• When I'm observing it, the lights will turn on and then off a few times, sometimes quickly, sometimes with several second intervals
• Turning DTL's on doesn't seem to affect the issue in a way I've yet observed
• I have NO issues when my headlights are supposed to be on and up. They have never flickered off for me when they are supposed to be on and high beams work.
• Unfortunately I have not be able to test if they continue to flicker if I put the headlights in the up position but leave them off. (I haven't been able to reproduce it in the garage.)
• It doesn't seem to react to disturbances of the car. It will turn on and off while I'm sitting still and I assume while driving as well. Revving the engine doesn't seem to affect it.

I'm worried this will be a difficult gremlin to find but hopeful that someone has the solution or some good ideas to check. People probably think I'm flashing my high beams at them.

The_Pied_Shadow

Here to add some more information I've found.

Having the headlights in the up position does not change this behavior
When the headlights turn on, no dash illumination comes on as it normally would if I switched the headlights on myself.

Due to these two new clues I'm starting to suspect this is related to the functionality that causes the headlights to turn on for a brief amount of time when the ignition is first turned on. It acts very similarly to this and it's making me wonder if some signal is being interrupted causing that to trigger again as if the key had just been turned. But I don't know how to explore this theory as I'm not sure what makes that happen. I still can't get it to do it on command. While it seems connected to a physical disturbance of the car, I can't do something that causes it ever time. I've jiggled wires, switches, doors, the car, and sometimes it happens and most of the time it doesn't.

Akagis_white_comet

iTrader: (4)

Start here with the Wiring Diagrams:
Foxed.ca - Mazda RX-7 Manuals

Turning the Headlight Switch to the first position outputs 12v on two wires. Red/Blue and Red/Green. One is Constant 12v for items such as the side marker lights, the other is Variable 12v for Dashboard lights and goes through the Dimmer Switch/Rheostat. I can't remember which is which though, so consult the Wiring Diagram to trace the circuit.

Turning the switch to the second position (headlights) triggers the Headlight relay and the Retractors to raise the headlights. Details for what wires get what signal(s) are in the Wiring Diagram.

It sounds like a failing Headlight Switch, but tracing each circuit will confirm this beyond any doubt.

The_Pied_Shadow

So it's possible for the switch to send power to the headlights but not trigger them to popup? I'll look into this thanks.

Barnahadnagy

I see three ways for the headlight to turn on: Theft deterrent activates it, the headlight switch activates it by turning it to the leadlights position, or the headlights switch activates it by turning the highbeams on. If you have the theft deterrent system my bet would be on that one. Since they don't come up, my second bet would be the high beam switch. I'm not sure how this works exactly, but I think it has a separate, physical switch that grounds the headlight relay, while the high-beam selection is done within the latching circuit. The regular headlight switch grounds both the headlight relay and the energizes the retractors at the same.

The_Pied_Shadow

I'm skeptical that they are being activated through the high beams. One of the first things I checked was if the high beam indicator lamp on my instrument cluster illuminated when they did this and I have observed that it doesn't (it does work, it illuminates when I intentionally activate my high beams).

The theft deterrent you mentioned I know nothing about and haven't heard of before in this car. How is that related to the headlights?

Barnahadnagy

Theft deterrent will flash the headlights when triggered. Mine works completely randomly (I have it disconnected) so its not beyond me to think it could randomly flash the headlights. Not all cars came with it, there should be an "alarm" indicator next to the handbrake on the center console.
The high beam indicator light gets its signal directly from the power rail after the dimmer relay, that is to say it will only illuminate if the high beams got power. However the high beam switch in the cluster does two things: turns on the headlight relay, then the dimmer relay. If it only does the first you get headlights and no high beam indicator either. (And I believe the second function is electronic with a transistor, so thats unlikely to have a random connection that works sometimes).