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scole665

Headlight strangeness.

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79 BRAT GL with 4 headlights lights up front. I know the low beams bulbs work, because they came on for awhile, then went off suddenly. The high beams work fine, all 4 come on. Oddly, they didn't work all morning on a long drive then the next day when I went out to start her, they worked... for a few minutes until they simply shut off again. All marker lights work when they're supposed to work. Where to start? Any suggestions for a novice?

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Edited by scole665

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Well first check your fuses and if they are fine check that the relays are working. Sounds like something in the electrical side is getting heated too much and cuts off due to it. But good place to start is the fuses and relays.

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See if the lights have voltage getting to them while the trouble is happening. If you have voltage at the light then the problem is most likely with the switched ground for the lights.

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I checked the fuse and it looked fine. I think there is one fuse for all the lights, so I doubt it's that. I don't know where to find the relay nor how to check it. I'm pretty much a novice when it comes to mechanical stuff. I guess I need a book! I do have a voltmeter, but I don't know how to use it to test what you suggested Cougar. The headlight has a three pronged plug so I don't know where to put the red/black wire on the voltmeter. Are you guys sick of me yet? I swear, I am a functional member of society! 

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OK, as it turns out I do know how to use the voltmeter. I have nothing at the headlight when the switch is in the low beam position. I do when it's in the high beam position. So, that limits it to a million other things. :-)  I was smart enough to unplug the high beams lamps so I can at least drive around an not piss the world off. 

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If you have no power at the low beam then one of the headlight relays is likely they culprit.  If you can get someone to tell you where to find it the relay  should be as simple as swapping the low beam and high beam relays. which will at the very least give you low beams for the interim until you can find a new one.

 

Mike

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Usually there is a head light relay for each side of the car and it supplies power for both the low and high beam lights for that side. Power passes through the relay and to the common wire of the light plug. The other two wires of the plug connect a ground connection for the selected light which passes through the light switch. You stated that you saw no power getting to the low beams so that may mean the light switch is not turning on the relay in the low beam position, which is usually turned on by making a ground connection to the relay coil. To verify that the low beams will work when power is getting to them you can manually supply power to the lead you saw power on for the high beams while the switch is in the low beam position.

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I posted this elsewhere as well, but this is a fairly similar situation to my problem. so posting here as well for some good feedback.

 

82 Brat: No lo-beams on either side, but hi-beams work fine on both sides every time.

 

With a test-light set up, I was able to get light going to ALL 3 wires on the female/switch side of the headlight plug on the driver's side with the switch in lo-neam position only.  Put a new bulb in, same behavior.

 

Have read some things here, but suggestion that it is relay doesn't seem right, as it says the relays are set up side to side, which would make this case peculiar that both had gone bad in much the same way.  Because it IS affecting both sides, should I definitely be looking at column dimmer switch?  Dash knob (the turning "wheel" style knob to the left of the steering wheel is the type this has)?  

 

Thanks for any advice!

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I was having simillar light issues on my Brat. Spent forever trying to track down the problem. Got one of these, fixed all my light issues. Only thing i had to do was get a female light connector ($3.00),and some spade connectors so i could rearrange how the main plug (3 wires) plugged into the new harness. Yours being an '82 you would need the 2 plug harness.
                
            
    

4-HEADLIGHT RELAY WIRING HARNESS H4 HEADLAMP LIGHT BULB CERAMIC SOCKET PLUGS SET
       

Edited by jonas
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Okay, as I have done at other times, posting this on a couple of different threads dealing with headlamp switch-ish issues...

 

 

Okay, have a lot to add in here, and still QUESTIONS! Did some very thorough testing with one of my mechanics today. It is a woman, so don't be surprised at the use of "she" when speaking of her. She is the real deal, ACE, has been in business for a LONG time, etc, and will work on anything, but specializes in imports. Where she is, Soobies and Toyotas are EVERYWHERE, and she knows as much or more than anyone I've ever dealt with for all Subarus since they have been coming over here!

So, to repeat my problem, have both brights, but neither low beam. '82, single head light, Brat. Light switch is the angled turning knob mounted to the left of the steering wheel. Bright switch is on the column/turn sig indicator.

Well, we tinkered and cleaned and sprayed and tested. All the same. Looked for the relay to test it, but then she decided it was probably in the dimmer switch assembly, so we started playing with that. I have five manuals, (one factory, HOW TO KEEP YOUR SUBARU ALIVE manual, 2 different Hayes that cover it, and one other that is not factory, but is well-known, prestigious, respected and expensive (the company is slipping my mind right now!)), so we started poring over wiring diagrams. We went through everything, I removed the switch so we could get at it and look at it/rebuild it, whatever it took, etc. After analyzing the wiring diagrams, we started testing again. We got to the point where EVERYTHING we tested down to the headlight connector was acting EXACTLY as planned/should be. Ground and power where it should be, etc. But when we plug in the bulb/lamp, it stops working right and we get brights on the bright setting, nothing on the lo-beam setting, and brights on the "flash" setting (pulling the stem toward you). However, something else we noticed was that the "flash"/pull the dimmer switch stem toward you action gets NOTHING, when the lights are off, though it does work when the light switch is in the, "on" position, though I am pretty sure it should, and though she didn't have any that old to check, it was her belief as well that most vehicles since the advent of the stem dimmer switch did that.

Another piece of info is that one of the prior owners had put in the halogen bulbs, as opposed to the sealed beam headlights. So we tried both. We tried rerouting the wires at the headlamp connector to see if they had been altered to deal with the halogens (we set them to factory/wiring diagram alignment, and literally tried every combination of the three wires just to see what was happening/if ANYTHING would work.

So, we are back to square one. The BEST we have gotten is brights in both high AND lo beam settings.

But, again, when tested with testing lights/probes, it acts perfectly normal at the connector to the headlight, but does NOT work with the current halogen, a brand new sealed-beam, or another brand new halogen, though I did check both of the halogens in another vehicle to make sure the bulbs were good, and they were.

ANYBODY got ANYTHING for me here????

Thanks!

Vic!

Edited by Vic Thrume

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Subaru like many Japanese cars run switched earths so One main power feed to the headlights and the Headlight switch switches the earth circuit and a changeover relay switches the high beams.

 

High beams are separated and serviced by the changeover relay, most but not all have a headlight relay that purely supplies power to the low beam system and power to the changeover relay for switching circuitry, Low beam switching takes place in the High/Low switch that is where the earth circuit is completed look at that area.

 

Datsuns 510,610's used the same switched earth systems and it can make wiring aftermarket lights or replacing headlights tricky because of the constant power that goes to the equivalent of what is the earth pin on normal headlight wiring and the other two pins that are normally switched power for high and low beam are in fact switched earths.

 

Your Mechanic might be a great Mechanic but in many cases Mechanics farm out Electrical work to Auto Electricians so sometimes get caught out with factories that do things differently such as switched earth systems.

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I had a similar problem with my 86' Standard, however it is the opposite. Both my low beams would work but both my highs would go off whenever I engaged the lever/turn signal on the steering column. I would still get an indicator light on my panel that the brights were on, but no lights. I tested with the voltmeter and discovered I was losing power to both lights at the same time when engaging my high beams. So I ran the wiring diagram in the Haynes repair manual and discovered that the problem was actually contained within the twist knob that turns the lights on and off. A connection within the switch had worn out and was still allowing power to flow through an alternate common when turned on, but would block this circuit from connecting when the switch to activate the high beams was engaged because it switched over to a completely different common.

long story short, if you're still having issues, try checking and replacing the switch knobs on your instrument cluster and see if it makes a difference. 

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Unplug the connector for the headlight switch itself, and give it a good look.

Do you see a discolored terminal? That could be the problem.

Was on my '85 BRAT atleast.

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I was having simillar light issues on my Brat. Spent forever trying to track down the problem. Got one of these, fixed all my light issues. Only thing i had to do was get a female light connector ($3.00),and some spade connectors so i could rearrange how the main plug (3 wires) plugged into the new harness. Yours being an '82 you would need the 2 plug harness.

                

            

    

4-HEADLIGHT RELAY WIRING HARNESS H4 HEADLAMP LIGHT BULB CERAMIC SOCKET PLUGS SET

       

 

 

Jonas - 

 

I have an 86 Brat and am having headlight issues.  The driver side  high and low beams work fine, the passenger side has dim low and no high.  I was looking at the wiring harness you posted and have one question.. where does it plug into to get power?  I think I've located the relays for the headlights ( two silver cylinders to the right of the fuse panel under the dash), would this harness just replace the existing relays?  or am i missing something?

 

Appreciate any and all help!

 

thanks.

 

:lee

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The 2 most common causes for this problem are the switch that turns the light on, and the indicator stalk that selects the high/low beam.

The switches have metal contacts which "gum up" after a while, and so they lose the contact.

They are also free to check and fix, so always the best to check first.

 

The high/low beam has 3 contact switches. Once you remove the steering wheel & indicator assembly, you'll see them on the back. This is the easiest.

Headlight switch usually has springs & small metal balls inside, so be careful pulling them apart.

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