Headlight crapped out on me, and Ive tried everything.

[Chuck Tribolet]

The only things that are common to the driver's side high and low beams and NOT to the passenger's side are the relays, the
combination switch, and some connectors. So if it's not one of those there are two bugs.

And if you look at the internals of the combo switch, it has a piece for the left high, a piece for the right high beam, and a piece
for all headlights. We know the second and third pieces are working.

Let's start over.

1. With the headlights on, check the voltage on each of the six headlamp relay terminals. You should have battery voltage on
all but pin 2. Pin 2 should have some very low voltage. Just for grins, check both relays. If things are as they should be, then
we know the relays and the battery saver control unit are good. (actually, since the passenger's side lights work, we know that
BSCU is good because it doesn't have anything unique to the sides).

2. Check the bulb for the high beam indicator in the dash. This going to mean pulling the "combination meter" assembly out, but
fortunately, that's not hard. Measure the resistance of the bulb. If it's good, it will have a resistance of maybe 1000 ohms, if bad
infinite ohms.

3. Try the high beams both by pushing the combo switch forward and by pulling it back. Those are actually separate pieces
inside the combo switch.

Chuck

[CanuckQx4]

Thanks Chuck I just went and did those tests
Took a few pics to show what I was doing, tests were with lights in the ON position. I also disconnected both headlight and foglight harnesses and gave them a few good bursts with electrical cleaner.



*click the pic to make it bigger to make out pin #'s if it helps*



I drew a #1 and #2 in the center of each relay to help with orientation as I flipped the camera to take the 2 pics aparently. #1 relay is closest the firewall side of the relay box, and #2 relay was closest to the headlight side.

I found 2 problems with the tests you said to do I believe. I had 12v at both #2 pins which you said should not exist there, and I had the little voltage (.8V) at both number 1 pins, so I figured you maybe confused #1/#2 in a diagram possibly. Also pin7 on relay #2 only had 5.8mv and was holding that number steady. So thats a problem..

Pin 5 on both relays measured half a volt lower than the rest of the measurements if thats of any relevance, they measured 11.7 while the rest of the connection (and the battery) read 12.2 volts.

So since I didnt have 12V @ pin 7 on the one relay I simply ran a jumper wire from my battery positive onto pin 7 and the headlight worked again, but would only turn on for the 4th click on the headlight click wheel. (Iforgot to check highbeam with this jumper wire installed damnit)

The highbeam indicator on the cluster did function in both push and pull positions, so I didnt pull the cluster out to check the bulb yet, figured I might not have to.

[Chuck Tribolet]

Nice pictures.

I hope that when you are jumpering to hot, you use a wire with a fuse in it. I've seen how fast a 12V battery can fry a wire. It's
damn impressive.

Swap the relays and see if the bug moves.

When I was helping Pathofinder in the shenanigans thread, I got to wondering if maybe the FSM had some of the relay pins
backwards. The '01 QX4 manual definitely shows battery power to pin 1 and pin 2 being grounded by the BSCU. And the FSM
has a picture of the pins on that type of relay (2M) on page EL-8, and it would indicate that the picture on top of the relay shows
the location if you turned the relay over and looked at the bottom of it. If that's true, then real pin 2 is under picture's pin 1, and
vice-versa. But that would also mean that real pin 5 is under picture's pin 7, but both are the output side of the relay, so I think
that relay is bad. BTW, it looks like the horn might use the same part -- check part numbers. If so, you can put the bad relay
In the horn socket, and you would have working lights, and one of two horns working until you can get a new relay,

BTW, FSM shows a different layout for the relays box than you have. See page EL-436.

[CanuckQx4]

Do you have a part number for the relay by chance??

I'll check my local scrap yard tomorrow if there open, I know they have a single R50 pathfinder maybe its got some of these relays I can grab. I'll also try and swap mine around but Im pretty sure I already tried that

I also noticed something weird with my headlight lamp indicator that illuminates on the dash cluster. It does NOT light up when the car is running. I tried a few times on the highway and it "looked" like only one headlight was coming on, but the dash indicator was not in either push or pull position.

Then when I got home and turned the car off, when I pushed or pulled the combo switch to turn the highbeams on the highbeam bulb would illuminate. Mind you this is all happening with my jumper going from my passengers positive to the drivers positive on the headlight sockets to make the light work.

[Chuck Tribolet]

Swap the relays before you go out and buy one.

I wouldn't be surprised if O'Reilley/AllParts/NAPA/AutoZone didn't carry it. I suspect Nissan used that relay in just about everything.

That relay is a double pole single throw type. If one pole is permanently failed open, it wouldn't surprise me to find that the
other pole had an intermittent problem.

[CanuckQx4]

No luck in swapping the relays, junkyard is open today so if I make it off work intime tomorrow I'll hit them up to

If I remember right you said if I had no voltage @ pin7 then I should have a blown fuse??

[CanuckQx4]

I must have had 2 bad relays, while I was at the car wash I noticed when I put on the highbeams there was a buzzing coming from the relay box. I pulled the relay that was buzzing (labelled #1 in my pics) and swapped it with the RR DEF relay,and it still buzzed and didnt work, then I put the horn relay in its place and it worked.

Both headlights worked in all positions, highbeam inidcator worked, everything worked. But I only have the 2 headlight bulb relays plugged in. The horn and RR Def relays are out.

I guess I'll just replace those.

[Chuck Tribolet]

No voltage on Pin 5 or 7 is a bad relay.

[CanuckQx4]

Any chance you have a part number reference for the relay. Would be nice to have that to price check different places

[Chuck Tribolet]

No part number. You might be able to get it from the Champion website.

[Chuck Tribolet]

I pulled a couple of the relays out of my '01 PF today.

1. Pin numbers are on the bottom of the relay and are consistent with the picture on top of the relay showing what it looks like
when you flip the relay over.

2. It looks like the relay part number is on the side of the relay like:

XXXXX
YYYYY

which would translate to Nissan part number XXXXX-YYYYY Try googling that.

[CanuckQx4]

Damn light stopped working in the middle of the snowstorm last night.

Earlier in the week I grabbed a few of these brown relays from an earlier pathfinder in the junkyard, I swapped them in but the light still didnt work so I made the same patch wire connecting the 2 headlights to get them to work.

Were you saying I was measuring the relays wrong??

I dont get why the light worked for a full week on its own with no backyard machanics, then crapped out on me

[CanuckQx4]

I went ahead and replaced the HID fuses 20amp fuses and swapped the relays again for the heck of it, no dice though, drivers light is out again...

Also I noticed in another thread that there was a "revelation" as to how to check the correct pin number, Im unsure if I was doing it correct or not. Maybe my pics will tell??

Id love this headlight to work again

[Chuck Tribolet]

The picture on top of the relay is as you are looking at the bottom of the relay, NOT as you looking down on the socket. That was
the revelation.

[CanuckQx4]

thats quite confusing if I even understand correctly

Guess Ill have to start the tests over

[Chuck Tribolet]

Pull the relay, flip it over and look for pin numbers next to the contacts.


Chuck

[CanuckQx4]

yup your right theres numbers under there, I literally had to put my glasses on to see them hah. I went back over the thread and I guess Ill do this test again and try again.

Let's start over.

1. With the headlights on, check the voltage on each of the six headlamp relay terminals. You should have battery voltage on
all but pin 2. Pin 2 should have some very low voltage. Just for grins, check both relays. If things are as they should be, then
we know the relays and the battery saver control unit are good. (actually, since the passenger's side lights work, we know that
BSCU is good because it doesn't have anything unique to the sides).

2. Check the bulb for the high beam indicator in the dash. This going to mean pulling the "combination meter" assembly out, but
fortunately, that's not hard. Measure the resistance of the bulb. If it's good, it will have a resistance of maybe 1000 ohms, if bad
infinite ohms.

3. Try the high beams both by pushing the combo switch forward and by pulling it back. Those are actually separate pieces
inside the combo switch.

[CanuckQx4]

So I took rediculous good care triple checking the pin numbers on the bottom of the relay.



The relay closest to the front of the car, for the passenger side light appears to be good, all 5 pins have 12V (except pin2 like you said)

But on the relay closer to the firewall, for the drivers side light, was not as lucky. I noticed pin 3 had significantly lower voltage than the others that where showing 12V, it only had 10.9volts. (Pin 1 & 6 had 12v.) And pin 5 & 7 had no voltage (was some small MV number)

The highbeam indicator did not function in either push or pull configuration, but I believe I already tested that the switch itself is good earlier on.

I swapped relays with the known good passenger side to the drivers side but no luck.

[Chuck Tribolet]

No voltage on pins 5 and 7 says that the relay hasn't closed. If the relay has closed, Pin 5 should have the same voltage as pin 3 and Pin 7 should have the same voltage as pin 6. So the question is whether the relay is bad, or it's not being told to close. So first
swap the two relays. If the bug moves, bad relay. If the bug does not move, pull both relays and measure the resistance between
pin 2 on one socket and pin 2 on the other socket. It should be zero. I'm guessing that the two pin 2s are tied together right under
the relay sockets.

Low voltage on Pin 3 seems strange. Pins 1 and 3 are tied together, I'm guessing right at the socket. Try measuring the resistance
between pin 1 and pin 3.

[CanuckQx4]

I swap relays and the bug doesnt jump, the drivers light doesnt work with either.

Resistance between both pin 2's with the lights off is .1ohm

Resistance between Pin 1 and 3 on both sockets is .2 ohm

Resistance of male pin 1 and 3 on the actual relays themselves was infinite

[CanuckQx4]

page 2 already!?

[CanuckQx4]

bump

[Buzzman]

I'm watching this with interest. Got home from a 2 week vacation, started up my 02 Pathfinder, and the passenger side low beam didn't work. High beams OK. Bought a new bulb...didn't work. Swapped bulbs with driver's side, both bulbs are good. Swapped relays, swapped fuses, all are good....still doesn't work. Now I know how u feel. Very frustrating. No voltage at the bulb, but everywhere else it's good. Aarrggg.
Keep us up to date if u don't mind. I'm riding your coat tail on this one. Thx.

[CanuckQx4]

Ya I dont know if its much different as I have HID's but the second Chuck posts up any news on what my latest test results in then I'll do that right away. Im hoping to have them function without my patch wire asap.

I think we need a donate to chucktribrolet paypal donation fund setup

[Buzzman]

Did some troubleshooting today. I managed to find electrical diagrams for my year of Pathfinder. Turns out the Pathy circuitry is different than yours. Relays are different, etc.
I've got it narrowed down a bit. The circuitry switches neutrals (grounds), and not the hot (12v). There is 12 volts present at the bulbs, both sides, but for some reason, the neutral isn't getting switched through to the RH bulb (low beam) when I turn on the lights. High beams works fine.
My Pathy takes the ground from the frame, passes it through the signal stalk on the steering column, then passes it through the DRL module, and then to the bulb.
I checked my signal stalk, and it seems to be OK.
I suspect the problem is in the DRL module. I'll continue with it tomorrow.
Yours is different, so this info may not help, but I wanted to share it with you anyway.
Cheers.

[CanuckQx4]

Ya quite different

I was hoping my test results and lack of highbeam indicator ever turning on, and drivers side highbeam never working would pinpoint to something

[Buzzman]

Yahoo. It works.
Spent the whole day messing with this problem. I checked absolutely everything, using the diagrams I have.
Finally tried using a long piece of wire to bypass the DRL module, and my lights worked.
Called the dealer, and they wanted $268.00 for a new module. NFW.
Called a wrecker, and they had a 2001 Pathfinder in the yard.
Went over there this afternoon and pulled the DRL module and the signal stalk (just in case).
Got both for $60.00 cash. Me happy.
Came home and swapped the stalk first....no change. Swapped out the DRL module and presto, I have my low beams on both sides.
Checked everything else, and it works great.
I'm a happy camper.
I can't even begin to imagine how much it would have cost me if I had taken it in to the dealer or a repair shop.
I would have paid dearly for the labour, as well as the part.
Hope you're as lucky with yours as I was.
Cheers.

[CanuckQx4]

Where is the module located? Wonder if that could be my problem

[Buzzman]

Module is located under the hood, next to the battery on the passenger side fender wall.
It's about 4'x4'x1' and has 3 plug/jacks.
It's the beige thing in the picture.
Good luck.
[*]

[asnorton44]

US R50s don't have DRL correct?