High Beam Issues - 2013

All,

 

First time posting on the forum. I've searched this forum, other Subaru forums and the open net for the issue I'm running into and I can't pin down what is going on. Summary, High Beams do not work. Low beams work fine. DRLs are fine. I noticed a few weeks ago when I was driving the high beams were sporadically coming on/off when I was hitting the switch. Now they are fully non-operational.

 

Here's what I've done/tested:

- All high/low H/L fuses have been visually inspected as well as ohm'd out. No issues.

- Confirmed 14v coming to the fuses when switch is engaged.

- All high/low relays have been ohm'd out. No issues. Also, you can hear the relays engaging when the switch is activated. Also, replaced the relay with a new one, just as a CYA. No changes. Working.

- DRL relay works as advertised. You can hear the relay engage when turned to Auto. Put it on my variable power supply and ohm'd both sides of the relay. No resistance. Working.

- Removed the DRL module from inside the front left wheel well. No changes to the high beam issue.

- Pulled the high beam lamp and visually inspected it; ohm'd it out and put it on the variable power supply. No issues, bulb is working.

- Ran an ODB scan just to see if it kicked any electrical component failures. It did not.

- NOTE: on the high beam circuit, I noticed that when the high beam is engaged that the two leads going to the bulb are both showing positive 14v. This one is throwing me for a loop. I can't say that I've see a circuit where both leads were showing positive voltage. Maybe someone can enlighten me on this one.

 

This is pretty much where I'm at. I've got a service call schedule this week for them to run a diag on it. Aside from all of the above, I'd welcome any input from the forum.

 

Thanks.

Nice thorough troubleshooting. Based on what you did, I agree the +14v on both high beam leads is strange (assuming you're measuring between each lead and an independent ground).

 

It sounds like you swapped the headlight relay for a new one? For good measure, I'd try that new one in the DRL relay position even though you measured the one in there. If all the relays work and you get voltage to the red wires at the bulb sockets, you know the problem isn't "upstream".

 

As for "downstream", my best guess is that you have a short somewhere in this wire I marked... The "B" coming into the page is the ground directly from the bulb sockets. If your DRL's work fine, that means the problem must lie between the relay and the non-resistor output. I'd check resistance between that relay receptacle and a positive source.

Yeah, grounded to the neg post near the fuse panel. Also, did swap the relay (both high and low...just for good measure). No changes to the high beam situation.

 

Also, checked fuses for the Body Integration Unit (fuse 7 and 12) and those are good.

 

Appreciate the, attached pic. I'm not working off any wiring diagram so I that helps to visualize the layout.

 

Yeah, I was just about to dig into the actual relay recepticles. 1) to ensure power and two put a jumper in there to see if that changes anything.

 

Appreciate the input.

If the DRLs are working, it sounds like you lost the ground path that coco26 highlighted. It's the only thing that makes sense.

So what happens when you turn on the high beams? do the DRLs go out, or do they stay lit? if the latter, I would still think the drl relay is the issue. If you bypass the drl relay and go straight to ground, do the high beams work? (for checking operation, make sure you are trying with a load on there) - if you are measuring power on both leads to the headlight bulb, then you have issues on the ground side (where the DRL relay is) - if the drl stays on even when you turn on the high beams, then that also reinforces that the drl relay is bad (possibly internally shorted on the power side)

Yeah, DRLs stay on. Last night I came across a service manual PDF that goes deep in the weeds on the entire electrical system. I'm going to start poking around that DRL relay connection on the fuse panel to see if I can track down, what appears to be, a ground issue.

 

Appreciate the input so far. I'll keep the forum updated as I get updates.

OK, removed DRL relay; High Beam relay; High Beam lamp along with High Beam (LH side...easier to work on) fuse. Traced line all the way to high beam and all checks out good. However, when I went to run a voltage check with the Low Beans on and High Beam switch activated, I had 14v from the fuse to the Red/Green line as indicated in the PDF (not sure what service I can use to attach thumbnail here). However, I still have 14v on the other line coming out of the lamp connector. What's even more odd is that I still have the DRL relay removed. So.....for some reason positions 5 & 9 on the wiring diagram PDF (see page Headlight System / HL-03) were getting 14v. 1) with the relay removed I don't see how those positions are getting power, at least from looking at this PDF and 2) as per the HL-01 page, when the head lamp switch is set to low beam and not Auto, the high beam lamp should be bypassing the DRL circuit and going straight to ground.

 

I'll keep poking the bear on this. Also, car was running for a bit doing this and I guess there's an AT Oil Temp thing and it kicked me this error. Now the key is stuck in the ignition and it won't shift out of park. I guess a cool down is necessary?

Ok - if I am reading the diagram right, and you have an H6, you should probably always see voltage on pin 5 if either the DRL or high beam is on - if the high beam switch is on, you should also see battery voltage on pin 9 (it's trying to flip the relay to switch the ground off the DRL resistor. when just the DRL is on, you should have voltage on pin 5, but no voltage on pin 9)

 

If you check the DRL relay, unpowered, you should see less than 1 ohm resistance between pins 5 and 8, with very high resistance (>1 megaohm) between pins 5 and 6. If you apply voltage between pins 9 and 7, you should hear the relay click, then you should have low resistance (less than 1 ohm) between pins 5 and 6, and very high resistance (> 1 megaohm) between pins 5 and 8.

 

If you are seeing real battery voltage at 9, that's from the BIU trying to turn the brights on.

 

I am not sure I am understanding your question - if your high beams are on, then pin 5 and pin 9 should be battery voltage irrespective of if the DRL relay is in there, but with the DRL relay removed, the high beam bulb won't light as either a DRL (low power) or high beam (normal power) - pin 5 is from the headlight relay and pin 9 is from the BIU

 

How I understand operation is:

 

If the ebrake is off, and the car is running, the DRL should turn on - you'll find voltage at pin 5 and no voltage on pin 9. (so the high beam sees the DRL resistor in it's ground path and thus runs at reduced voltage)

 

If the ebrake is off, and the car is running, and the headlights (low beam) are on - you will find no voltage on pin 5 and no voltage on pin 9 (the DRL should not be on when the headlights are on)

 

If the ebrake is off, and the car is running, the headlights are on and the high beam switch is on, you should see voltage on both pins 5 and 9

 

(note - I have a manual transmission - for an automatic, you might need the car in gear to get the DRL to turn on - I can't check that with my car)

Alright, after some testing the bottom line is that the high beam circuit is working.

 

I tested the ground connection, coming from the DRL module, and it tests out. With the high beams on, and the DRL module in, the high beam circuit does not work. However, if I remove the DRL module and turn the high beam circuit on, I get 14v going all the way to position 5 of the DRL module. If I put a jumper from 5 to 6 or 5 to frame ground or 5 to battery negative, the high beams come on.

 

So at this point, I'll assume that it's the DRL module that's issue here. Again, I put the module on my variable power supply, along with my multimeter, and everything tests out voltage and ohm wise. Obviously, I can hear the relay switch when the power is supplied.

 

I'm gonna put in a new module and see if that's the kicker. It's all very odd that it appears to bench test fine but has issues closing that 5 & 6 position to complete the high beam circuit.

 

Note here, the 14v at both pins of the LH high beam lamp through me for a loop for a hot minute. After looking at the wiring diagram, it makes sense now being that the RH high beams are tied into that circuit, which runs to the position 5 of the DRL module. It makes sense to have it built that way so that if a high beam lamp goes out, it does not effectively kill the circuit.

The DRL "module" is just a resistor; it either works or it doesn't. Neither case should have any effect on the low beams working.

 

Some of your troubleshooting steps seem conflicting. Are you sure you hear the DRL relay clicking and not another relay?

I am guessing by module they are referring to the relay

My module I meant relay. Located in the fuse box.

100% positive DRL relay is clicking. Not only do I hear an audible "click". When I put the relay on the bench and put power to pins 9 & 7, I can see the ohms drop between pins 5/6/8, with 6 & 8 being the pins that the relay switches between.

drops to what? a 9005 bulb pulls around 5A of current - the resistance spec for the switched relay is less than an ohm - it doesn't take a ton of resistance to have a sizeable voltage drop across the relay. If the high beams work when you jump directly between pins 5 and 6, that's pretty much telling you the relay is probably jacked.

If the high beams work when you jump directly between pins 5 and 6, that's pretty much telling you the relay is probably jacked.

 

Yep, if jumping 5 and 6 works, that leaves only two possibilities. Either the relay is bad or it's not making good contact in the socket.

DRL relay was the issue. Appreciate the collective insight. Still not fully sure why the relay was not making a good connection. I'll peel off the cover on the relay and see what's what. Again...thanks for the collective help.