2000 Tribeca head light issue:

[hflier]

My son stopped over yesterday with a headlight issue on his vehicle.
A 2006
Subaru B6 - head light problem.

He has fog lights, parking lights, high
beam and low beam headlights on his car. His car is also equipped with daylight
running lights.

He drove home the other night and everything was working
perfectly.

He drove out of the garage the other morning and noticed that
his headlights were not working properly.

Currently, his drivers high
beam light works correctly.
His passenger high beam does not work at all.

When he switches to low beam, both low beams are very very dim.

His
parking lights work correctly. His fog lights work correctly.

All head
light bulbs have been replaced, are new and function perfectly if hooked to a
separate battery.

All head light relays and head light fuses are new and
have been tested for correct operation.

No sign of any grounding issues
with the vehicle.

In the wiring diagram, there are 16 wires that feed
into the daylight running light module and right now is the primary area of
suspicion for his difficulty. But if any one has a Subaru head light issues and
has had a satisfactory solution; I would appreciate any information.

On
this particular car, one side of the head light bulbs have +12 volts on the
bulbs any time that the key is turned on. The on and off of the bulbs happen as
a result of the ground side of the bulbs being connected or not connected.
However, with the way that wires are routed into the daylight driving module, it
is impossible to know the exact switching patch for these ground control
voltages.

Tough to drive around with only one high beam headlight
working.

Thanks for sharing any thoughts or experiences with this sort
of vehicle lighting system issue and resolution.
 

[Cougar]

Check the wiring near and under the fuse panel under the hood. Look for connectors with signs of corrosion on the pin connections of the connector. Some others have had this kind of trouble though with a different model car. The troubles are similair though.

[Dinky26]

I just had the same problem tonight, only it seems as though both high beams are good with no low beams at all.

[hflier]

The next thing that we are going to do, is to remove the shorting block that is on top of headlight harness bulkhead F109 that is located directly below the fuse block.

Pop up each corner of the fuse block and then lift the fuse block out of the way.

 

The flat white square object below is the shorting block for F109. We will remove this and then use a shorting wire from each of the separate ground head light connections and will short each one in turn to the battery ground.

 

If each headlight in turn works correctly, we will be able to give a clean bill olf health to the front wiring harness and then look at the headlight switch, which is about the only thing that we have not checked.

 

We will also have to check the ground connection that is up behind the three doors under the dash which grounds out the drl module and light switch.   If a wire or wires do not have a good ground at that point, it could be leading to the problem.

[Fairtax4me]

You should have 12v at all three terminals on each light with key On. If you have 12v on only one terminal there is a connection issue at the bulb. With no ground path there should be 12v on each side of the load (the lamp).

 

You could check the lamp circuits back to the DRL module by removing or back-probing the connector and grounding the pins from the lamps. If they light normally with the pins at the connector grounded, the problem is probably the DRL module. If the lamps do not light, work your way forward in the circuit.

[Cougar]

For the passenger side high beam issue check to make sure the headlight fuses are ok and have voltage on each side of them by probing the slits on top of the fuses.

[hflier]

Posted Today, 06:17 PM

 

 

My son was back from his business trip and we were able to spend some time on his vehicle.

 

First, I finally sat down and got my head turned about a 1/4 turn to the right, after I finally realized that the color coding for the wires on this vehicle from the conventional american vehicles that I am used to working with. i.e. from a lighting situation, we effectively have a positive grounded vehicle in a manner of speaking. i.e. they color the ground wires with red colos and the color the voltage wires with browns and black.

 

This had given me issues when doing my initial trouble shooting because I would just automatically look for ground on the brown and black wires and voltage on the red colored wires. However, the opposite is true.

 

 

 

I went back to basics, as Cougar and others have suggested and just started from the beginning on the belief that I had missed something initially.

 

Have correct voltage at the output of fuse 6 and 7 which are the headlight fuses. But I DON't have voltage at the bulkhead pin, where the voltage is supposed to leave the fuse block.

 

So, it appears that there is an open circuit on the inside of the fuse block, between the output of pin 6 and the bulkhead connector of pin 6.

 

Furthermore, when I check the front wiring harness from the fuse block bulkhead connector over to the main connector on the front frame for the headlights, I find another open in that wire as well.

 

 

 

If this continues to check out, I am guessing that perhaps a wire got pinched or shorted out and burned open, and also did the same thing for the fuse block connector. The interesting thing about this situation is that it did not cause a fuse to fail.

 

 

 

Since we did not have another fuse block on hand, I installed a temporary wire from the + 12 volt battery terminal to a fused 15 amp wire over to the high beam + wire on the high beam headlight.

 

 

 

This fix temporarily took care of the lack of passenger side high beam light.

 

It also took care of the very dim low beam lights that were lighting up due to sneak currents passing backward through the high beam light bulbs.

 

 

 

However, there is still an issue on the low beams.

 

I have no drivers side or left side low beam light.

 

Also, the passengers side low beam light although much much brighter than what it was, but is still only about 1/2 brightness level.

 

 

 

Unfortunately, my son had to pack up and leave for now, so was unable to do any more voltage checking.

 

 

 

Since the fog, high beams on and off, I suspect that the light switch is all right but have another issue with the front wiring harness on the vehicle.

 

 

 

When more time allows, will continue the testing and checking

[Cougar]

Some folks have been finding trouble under the fuse panel that is located under the hood. Moisture damage to the wires in the connectors under the panel has been found by some folks.

[hflier]

Cougar,

As I reported earlier, we have taken out the fuse panel, and have taken out the bulkhead connector that is used to combine headlight wires together to run to the switches.

In the case of this car, everything appears to be pristine, with no damage or problem of any kind found in either of these areas.

 

Roger

[hflier]

Basically, the problem has been resolved.

The problem was solved by finding the open wire that ran from the drivers side fuse block to the voltage supply side of the passenger high beam headlight in the front wiring harness.

Since I did not want to replace the wiring harness, I cut the wire about 10 inches from the fuse block and 10 inches from the light bulb and spliced in a new wire to replace the wire that had apparently opened somewhere in the wiring harness.

This put the correct voltage on the high beam light on the passenger side and eliminated the sneak paths for voltage that were causing the dim lighting of the low beams.

In addition, from starting the job, until that time, the light bulb on the low beam drivers side had burned out. So, replaced both low beam headlight bulbs with a matched set of replacement bulbs.

In addition, during the testing, it seemed that the general battery  voltage was low.  So, after completing the other work, took the vehicle over to the battery shop to have the battery load checked. Sure enough the 3 year old battery was in need of replacement. Since it was a NAPA battery, I then took the vehicle over to the NAPA store and found that there was still a good bit of warranty left on the battery and was able to get a new battery for $30.

 

Finally, the job is complete and all of the lights are working again.

At the end of the day:

1- wire - $1.

1- pair of high intensity H4 low beam light bulbs - $30

1- replacement auto battery replaced under warranty - $30

 

Total $61.

[Cougar]

Glad to hear you got things fixed up. I suspect the light wire problem was near the fuse panel but it could of been the other end. Instead of cutting both ends of the link I would have tried to hunt down the trouble because I hate wire modifications. There most likely was a connector in between the end points and the problem is in the connector. This is where having a factory service manual pays off in spades. It will show you where to find any connector in the line.

[Dinky26]

Fixed my problem too, both bulbs burned out at the same time  , would not have thought they would go at the same time

 

Should have guessed that might be the case though

Edited March 6, 2013 by Dinky26

[hflier]

Cougar,

I have the factory manual.

I had both ends of the same wire. It was the red/green wire that started at the fuse block and ended at the light bulb light bulb assembly harness.

It was not the connector, because I clipped the wire - 10 inches from each end.  The wire runs from the fuse block inside a wire harness that contains 20 other wires, goes up to the radiator, down along the radiator, under the radiator, up the other side to the headlights.  Somewhere in the wiring bundle - that was at least 10 inches from each end the red/green wire opened up. I had no desire to pull out the wiring harness, strip off the bundling and find the precise spot where the wire was defective.

 

But, I certainly do agree, that if only a connector is bad, or a splice is bad, that it is much better to resolve the issue at the defect location.

 

Be safe

Roger