My 97 Impreza headlights periodically go out then return 2-3 seconds later.  I've not noticed any rhyme or reason.  I could be driving or just sitting at a traffic light and they will go out simultaneously, then come right back.

 

I've replaced, both side bulbs and relays but it hasn't cured it.  Also changed the fuses.  I don't see anything evidence of bad/frayed wiring at the sockets. 

 

Anybody come across this before?  Suggestions?

 

Thanks!

Have you tried jiggling the headlamp-switch, to see if that either turns the headlights on or off?

 

What I mean is:

- if the lights are ON, does jiggling the switch turn them off?

- if the lights turn OFF on their own, does jiggling the switch restore them back to on?

Jiggling doesn't turn them off when on.

 

Unfortunately, when they do "turn off" they come back on in a few seconds so I don't get the chance to play around with things to see if it makes a difference.

Could be the hi/lo switch going bad. Does it do the same if the high beams are on?

Haven't tried that.  The problem is the issue is so random and infrequent, returning to normal so quickly it's challenging to try different things. 

Will it happen if you just sit in the driveway with the headlights on?

If it will, leave them on both high for 15-20 minutes then leave them on low for 15-20 minutes and see if it happens only on low, or on both.

I've messed around with my headlight relays in my 95' Legacy before, and if one relay is pulled while lights are on low beam, both lights go extremely dim as it's apparently trying to send a low voltage to the high beams instead. If inside the car, it'll appear as if the lights are completely off, but if outside the car and looking at them, they appear as if 9v is being applied to low beams, or what it'd look like if the battery is dead, but it's the high beams being under-powered as it's creating a short to the high beam filaments despite low beam switch on.

 

Did you actually replace BOTH low beam relays? Or did you just reverse them? If one was bad or going bad, or just being tripped up from a surge or an infrequent short, it might be cutting power at the relay, then it resets and goes back to working. 

 

Like Fairtax suggested, try idling the engine and leave head lights on, but sit outside the car and watch if the lights are going really dim, or completely off.

Edited March 21, 201610 yr by Bushwick

I replaced both headlight relays with new ones.  Tried what Faritax suggested but couldn't get the lights to go out, they worked just fine. I unbolted the fuse box and moved that all around while watching for any change in the headlights---none. 

 

I guess I'll need to wait until this problem becomes more than intermittent. 

Have you checked the plug connectors going to the bulbs? While it's unlikely both could be dropping at the same time, I know I've had issues with my bulb connectors being brittle and loose at the bulb's spade terminals. Ran a conductive grease in each connector to help. Might be worth tracking down the head light bulb's ground to chassis and see if it's corroded or broken. These are things that could be influenced by the car's movements and road vibrations.

 

However FT is probably correct that the switch is wonky. I ran into an issue recently with the wiper stalk set on intermittent in really cold weather cutting in and out, but it was clicking a relay loud enough to alert me to it. 

Edited March 21, 201610 yr by Bushwick

Picked up a used switch, however it's par of the entire assembly (clock spring, wiper stalk).  do I have to replace this whole thing or can I just detach the headlight switch and swap that?

I don't remember if the headlamp switch can be separated or not. Been a while since I've had one apart.

The clock spring is separate. That has to be removed before the switch assembly can be removed.

 

When you remove the clockspring, use a peice of tape to hold the middle spinny part in place so it doesn't turn around and get out of center. If the clockspring is installed out of center it will rip the ribbon cable inside when you turn the steering wheel.

Edited March 27, 201610 yr by Fairtax4me

thanks.  Yes, it seems like the switch is fully integrated with the turn signal.  Steering wheel has to come off, etc. 

So I replaced the multi-functioned switch and it appears (so far) the headlight issue I solved.  While removing the switch connections from under the dash, I snapped the green locking tab on the airbag connector.  The connector still "connects" but the green tab won't stay depressed.  When I start the car now I'm getting air-bag light on the dash. 

 

Any thoughts how to remedy this issue?

Gonna have to replace the green tab.

The tab holds a grounding bar away from the wire terminals. Unless the tab is pressed in, the wires are connected by the bar. This the light turns on because that circuit is grounded. The airbag system will be disabled whenever the light is on. So the airbags will not deploy.

 

You may be able to get that green tab to pop out of another connector, but worst case you will have to replace the connector.

Can you solder?

 

Does it have the 2 wires in the connector or 3 wires?

Edited April 10, 20169 yr by Fairtax4me

I can solder.  I was able to pop that green tab out of another connector.  the little coiled spring that actually makes electrical contact is a bit of a pain to align.  Think I got it though..

 

The tab is nice a "springy" as it should be.  Reattached everything but she's still throwing a light.  Should the light go out right away if I got it or is there a delay?

Was it a spare connector or another connector in the car?

It was from a spare clock spring.  I get the green tab to latch and it's spring load feel right.  I must not have the internal coil spring aligned quite right so when it's connected it will break that ground you mentioned