M35 Headlight problem

[cincyken]

3 months ago i bought a used 2007 Infinity M35. Love the car. I previously owned a 1998 Volvo S70 that i did all the repairs on myself.
Starting a couple weeks ago, the left front headlight low beam would go out after a minute or two of driving. I removed the bulb (a $100 D2S) and replaced it as the first step...typically a headlight coming on and going out is not a bulb problem but a lose connection. After it was all back together, i took it for a drive and the headlight went out again. All the other lights are working fine.
Since i lack experience with this car, what should my next step be?

[TDot]

I have no idea, but my initial assumption is you are correct with the loose connection, or a short or bad ground. The vibration from running triggers the issue. My question is do you have to be driving for it to go out, or can you just start the car and let it run and it will go out after a while? If it will go out standing in the same place I would jack the car up, and wait for it to go out after starting it then check the voltage at the headlight assembly. If it's low, leave the VOM connected and wiggle wires around to see if the voltage jumps up. If it doesn't jump up start backtracking to where the wire originates if that's possible to see if the proper voltage is coming out. Don't assume it's supposed to be 12V, check the field service manual to make sure about the voltage, or another member might be able to confirm. Also you may want to clean the contacts on the connector.

First I would change the fuse though because sometimes fuses don't completely blow and intermittent signal can jump the blown fuse.

[cincyken]

I took it apart again, there is no voltage to the socket connecting to the bulb...0 volts, not even .5 volts.
I would think if it was a fuse, it would effect both low beams, would it not, but it is only the drivers side low beam. So, it's not the bulb (wasted $100 replacing it), it is somewhere in the curcuit feeding the light socket. I don't know where to go from here.
I hate to take it to the Infiniti dealer. They be good but very expensive.

[kmiles]

It could be a loose connection, bad ground, bad relay, or bad ballast. There is a single fuse for both sides, so it won't be the fuse. I'm betting ballast or relay.

Here is the link to the service manual on this site: http://www.nicoclub.com/FSM/M/2007_M45-M35/lt.pdf

The troubleshooting page for your symptom is on page 63.

[TDot]

No, there is a fuse for the right and fuse for the left I believe.
Where did you check the ground? Don't check the voltage against the socket ground, ground against the chassis because the socket ground could be faulty.
Start back where the fuse for that side is. Once there go to each point/connection after that and check for voltage and continuity with the VOM. Once you find the point where signal isn't passing through, just replace that wire by splicing. There should only be about 10ft of wire and harness you have to check through.
If you need step by step check the field service manual "LT" pg 49 on for xenon version (in szh's signature). That will show you specific sockets in the harness to check instead of splicing into the wires. If you still have issues reading through that check back and I'll try to decipher it with you.

[cincyken]

I am starting to feel like i don't know what i am doing anymore (with cars).
I looked in the owners manual and it identifies two locations for fuse boxes. One by the battery and one by the E-brake.
Neither box has any fuse numbers to identify the fuses.The document you sent me identifies fuse no. 86 as the one i am looking for. In addition, no fuse is indicated as to the headlights in either box.
I am going to make some assumptions:
1. The low voltage headlight low beam relay is probably a double pole relay, one for the LH and one for the RH.
2. The RH pole feeds fuse 76, and the LH pole feeds fuse 86.
3. If this is the case then i think i have a Headlight low beam relay that is pulling in enough to energize the RH beam but only partially for the LH beam.
It is a guess but i have seen it happen before on other cars.
Questions;
where is the "Headlamp low relay" located?
Where are fuses 86 & 76 located?

[TDot]

The relay and fuse for the light is in the engine.
http://www.nicoclub.com/FSM/M/2007_M45-M35/pg.pdf
Pg 28

[EniGmA1987]

I took it apart again, there is no voltage to the socket connecting to the bulb...0 volts, not even .5 volts.
I would think if it was a fuse, it would effect both low beams, would it not, but it is only the drivers side low beam. So, it's not the bulb (wasted $100 replacing it), it is somewhere in the curcuit feeding the light socket. I don't know where to go from here.
I hate to take it to the Infiniti dealer. They be good but very expensive.

Most likely it is a bad ballast or relay. I say ballast because I have had my ballast go out too and they do die after a while, usually before the bulbs go out on these cars. Or it could be a relay going bad since that sort of behavior sounds typical for a bad relay, except I would also think both would be affected. Im not sure where the relay is located exactly, but hopefully it is easier than changing the ballast. Try to change out the fuse and relay first.

The ballast is a total pain in the butt. The Matsushita ballasts we have (http://www.theretrofitsource.com/compon ... lasts.html) use a steel braid over the output wires, so it is extremely hard to cut the wires, and additionally the wires are run INSIDE the headlight assembly so that you must completely disassemble the headlight to do the work and then bake it shut again to restore the watertight seal. The dealership told me it was like $1200 to change out if they did it, but after doing the work myself I would have gladly paid that. Fortunately that cost is already almost as much as full custom headlights would cost, so you might as well use this opportunity to send your lights off to Mr_Luv and get them all pimped out. I first went the cheap route and replaced both my ballasts and bulbs for about $100, did the work myself and they worked. But cheap systems like this are not worth it. The bulbs start to color shift within the first few months, the ballasts are lower quality and wont last nearly as long (you got 7 years on your OEM ballast), and the relays they use for the new harness seem to be lower quality. Just fork out the money and either get OEM parts or have some nice custom work done. Id recommend the custom route, which can still use those Matsushita OEM ballasts anyway if you want to. My low beams that Mr_luv did:
what-did-you-do-to-your-m-or-q-today-t4 ... =Headlight

[cincyken]

Well, I was able to locate the third fuse box behind the battery (why make it so hard to get to it?). I tested the relay, it is fine and it does provide power to both LH and RH low beams so that is not it. I swapped the 86 and 76 fuses, but that was not it either.
I know the next logical step is to check the wiring, which i have not done yet.
I believe the ballast y'all are referring to is actually a transformer that steps up the voltage from 12v to 700v for the Xenon bulb.
Tomorrow, i will check the wiring, and then if still no luck, i will pull the headlight and change the transformer.
I am learning.

[EniGmA1987]

The HID ballast voltage should only be something like 85v AC power. It just spikes the voltage at the start with capacitors to stuff like 20,000 volts to ignite the bulbs. If you end up replacing the ballasts then you can buy these:
http://www.theretrofitsource.com/compon ... lasts.html

Those are our OEM ballasts, only a newer generation model. They will work best because they will mount directly back into the same spot as the bad ones you remove and have the same plugs for connection. When I had my headlights done I replaced my broken stock ballasts with these newer gen models too. They works great.

[cincyken]

The wiring (as best I can access it) is not the problem. I see no alternative but to now pull the drivers side headlight assembly. I will buy the ballast thru the above link, then when it arrives, i will pull the headlight.
As a side note, i friend of mine is the service manager at a large VW dealer here in Cincinnati. He says he has seen the symptoms my car is having many times on VWs and it is usually the ballast. He says the nominal life rating of the ballast is 2,000 hours. If you leave the low beams on, that is about 4-5 years.
It is my understanding that the only way to get to the ballast is to remove the headlight assembly...correct?

[EniGmA1987]

Yes that is correct, but it is far more work than that. You need to remove the outer plastic lens from the assembly and completely disassemble the headlight to remove the old ballast because the output wires from the ballast are hardwired, not a plug, and are run inside the headlight itself. They also have a steel mesh around the wires making cutting the old wires problematic. If you want, you can try to cut through them and splice the old wires into the new ballast. That would let you get away with not completely disassembling the headlight. It may not work though, IDK if there is enough space to work with the wires like that or not. Speak to mr_luv and he may help you with exactly what is required and the steps for removing the stock ballast, he knows those steps better than I.

[infinity72485]

I'm having the same issue but mine is with the passenger side low beam, can u guys tell me where the low beams fuse is I think it #76 and #86 that I have to look for I'm not sure where they're located in my car

[cincyken]

I can because I could not find them either initially.
Next to the battery, on the passenger side of the battery, there is a plastic cover (not the fuse box in front of the battery).
I had to remove my battery to access this fuse box cover. You can remove the plastic cover by lifting the plastic snap with a screw driver.
Under the cover are the two fuses you are looking for and also the low beam relay.

[infinity72485]

Thanks for the help cinc I'll do that this weekend I hope that's what the problem is

[junkstopshere]

http://www.nicoclub.com/FSM/M/2007_M45-M35/lt.pdf

page 31

Other sections of the technicians manual

http://www.nicoclub.com/FSM/M/2007_M45-M35/

[junkstopshere]

There are no relays to be replaced. Infiniti uses solid state switching and the relays are not physical in nature to be replaced.