Head light woes..

[tiggs]

Did I mention I hate my car? I'll spare the long story...

Anyway

My LH headlight is out. Easy enough, replace the bulb (pop ups btw). Well after breaking the bracket to get the old one out and new one in, the headlight is still out. Connection is good, fuses are fine (not blown at least) so where do I begin for the rest of my troubleshooting?

[tiggs]

Tried the old and 2 new bulbs. Nothing.

Checked for voltage with a mutimeter, getting good voltage right at the plug. So I figured I'd try putting the headlight in then testing the voltage again from the contacts on the headlight. I get nothing, zilch, nada. Not even a sign of voltage. Granted I don't know exactly how to use a multimeter all that much but I know what 0 means and I know numbers come up when I tried directly from the plug.

Any ideas? Why does my multimeter get voltage but the headlight doesn't?!

[Jung918]

Where did you place your negative probe? I'm guessing you placed it on the body somewhere. The ground for the headlight could be bad.

[mothon]

when it went out was it intermittent or did it just all of the sudden go out?

[tiggs]

Just all of a sudden went out and stayed out

I used the top (middle, flat while other too are vertical) as the ground.

I'm no electrician so I kinda did the whole, test and see what does what thing

I could be wrong. I most certainly am eh? School me!

edit: Ok just went and tried using the negative battery post as a ground

Before doing so I turned my mulitmeter to do the 20v range, tested between both battery posts and got 12.55V with the car off, I'm good there I'm assuming.

Using the negative post I get (I'll try to illustrate):
__(A)__
| |
| |
(B) (C)

Highbeams On
A=0.60
B=0.05
C=0.10

Highbeams Off
A=0.80
B=0.03
C=0.09

hope that made sense! Remember, me=not an electrician so I may have the multimeter setup wrong, just tell me what to do!

[Xren17]

Not sure what you're trying to illustrate but put your negative probe to the black wire and the positive probe one at a time to the other wires with your low and high beams turned on. If you're getting 12V to each line than you're wiring is good. If not, check your fuse with the multimeter and check for resistance. If you're getting nothing that means the fuse is blown even if it looks good. Also since your RH light are good, you can use that as reference to see how the headlight is supposed to work.

[tiggs]

Yeah the forum sw doesn't let me put spaces where I wanted em I guess

So yeah, there's 3 contacts and each wire is RED.. closer look, red w/green strip, red w/blue stripe, red w/white strip

white was the one with 0.60 and 0.80
blue was the one with 0.03 and 0.05
green was the one with 0.10 and 0.09

that would be high beamon and then highbeam off respectively

I guess I'll go try and get the other headlight out to test as well, I had a heck of a time with the crappy bolts on the LH

edit: yeah not happening, not unless I cut to bracket or something like I did with the left. Not really willing to do that right now. The screws are too old and rusted and are as soft as butter whenever I try to unscrew them, they round out with barely any pressure.

[tiggs]

Anyone got any ideas? Fall is setting in and I have to tdrive in the dark each night now, I gotta find out what the hell is wrong

[mothon]

You should check voltage on the side that is working and compare it to the side that isnt working. Maybe its just not getting enough voltage.

[tiggs]

So lets assume they aren't getting enough voltage, what do I check then?

I can't really afford to strip out and cut the screws off on the RH side yet, not until I get some new brackets atleast. So lets just say hypothetically I did compare them and the voltage was low on the LH side vs the RH side (look at my numbers, they're very low anyway like under 1v so it's probably the case) what/where would I look next? Fuse is fine btw.

thanks for the response btw

[Jung918]

Did you check the relay?

[tiggs]

Yeah... No I haven't. I didn't know there was one or where to find it. I looked in all the regular places (underhood fuse/relay box) and kick panel fuse panel and so nothing except for the LH and RH fuses underhood.

Enlighten me where to find it? I'll be searching and if I find anything I'll post it in here but it's not something I expect to find much info on. I've even gone through the fsm and nothing about a relay... Unless I'm blind.

[tiggs]

So I only had like two seconds to look but is this relay located under the air filter, well, under the intake tubing that goes into the air filter? right behind the LH headlight? I did manage to get a look at the cover which had a RH R/T and LH R/T something like that.

[g6civcx]

Check the headlight combination switch. Sometimes one of the contacts get dirty and power doesn't make it to one headlight.

Get a new one or take the old one out and clean it.

This is a common problem on older Nissans.

[dre]

just run a wire from the other headlight high beam and call it a day

[g6civcx]

just run a wire from the other headlight high beam and call it a day

With all due respect, you're doubling the current on a single wire. Better make sure that one wire can handle two 55W+ bulbs drawing current, or you're risking a fire.

It's like you can't double the number of cars without widening the freeway.

[koukimonster139]

heh that was cute ^

[ZX88]

try the combination switch i was having similar problems with my lights and this seemed to work heres my write up.


http://www.zilvia.net/f/showthread.php?t=145000&highlight=combination+switch+fix

[trmn8r]

are the headlight modified or stock. if the light are in series one light might be drawing all the voltage. check the ground of the bulb. put your multimeter on volts and put one lead on the ground portions of the bulb. and the other lead where the wire touches ground. your voltmeter should say 0 volts. if it says OL then theres an open in the gound, if its reading any voltage than you have resistance in the wire wich is drawing voltage away from the headlight bulb. if theres power going to the bulb and the bulb doesnt come on. then it must be a ground issue

[trmn8r]

Nice read up. thats some good stuff there.
try the combination switch i was having similar problems with my lights and this seemed to work heres my write up.


http://www.zilvia.net/f/showthread.php?t=145000&highlight=combination+switch+fix

[tiggs]

Thanks for the ideas guys. I'll be looking at the combo switch later when I am home from work. Thanks for linking me to your write up, much appreciated!

Just for clarification: Both the high and the low beam on the driver side are out. I have tested for voltage and my voltage results are above, using the negative battery post as a ground. The headlights are stock.

[tiggs]

So I finally got around to checking the headlight switch. Cleaned it off, messed with the connections a bit, studied how it works... After gaining a good understanding of how it works (and messing it up a few times) I got it all working properly.... Except my driverside headlight STILL has nothing.

I'm having a hard time locating the grounds for the headlight. Anyone got any bright ideas?

[tiggs]

I took my combo-switch out saturday and cleaned it up, didn't help.

Last night I go to drive home about 15 miles and realized I had no parking lights. I knew I had probably bent the copper strip in the combo strip, so I just kinda rode the brakes very lightly. Tonight I go to fix that strip, yeah works fine without doing anything. Anyway I had it all plugged in with the cover off so the copper strips are exposed. I wanted to test each connection one by one.

Parking lights are good. Passenger side headlight is fine, high beams were a little off but fixed that connection. Then by mistake the little screwdriver I was using to push the connections down connected the strip for my driver's side high beam to the parking lights. This shocked the heck outa my father as my driver's side high beam flashed him. He was like, "Whoa! It came on but went off, what'd you do?" so I jumped it on purpose and it stayed lit as long as the connection was jumped. So I tried the low beam and it did the same thing.

So what's going on? Is this obviously the switch? Or is there most likely something else causing the problem. I just don't understand why both the high and low beam connections operating normally don't do anything but when jumped they turn on fine. One would make sense to me but both? Just a coincidence?

Someone chime in and save me having to take my car to a shop since I'm at my wits end!

[Xren17]

From your description you were just running your headlights using your parking light wiring.

This is what I would do.

1. Disconnect all the plugs for my headlights and parking light.
2. Turn parking light on.
3. Check to see if I'm getting +12V at the end of the plug.
4. If you are getting 12V then your parking lights are fine.
5. If not, you have a short and you need to trace the line back to your power source.
6. Repeat 1 to 5 for your low and then your high.

[tiggs]

So what your saying is that all of the power for say, the parking lights run though the combo switch? That's the only way I can see what you said making sense (in my mind, please don't be insulted I'm asking a genuine question because I'm not understanding)

What I thought with the combo switch was the it was sending an on/off signal to a relay or something of the sort. I just kind of figured when I had jumped the headlight with the parking light switch I was sending a signal to the headlight relay that turned it on etc. Maybe I'm completely wrong though.

[Xren17]

Tiggs, no insult taken. You are correct in thinking that a signal is use to turn on a relay to power the headlight. I thought you had accidentally shorted it at the headlight assembly and not the combo switch. So if it's at the switch than more than likely you have a defective combo switch. Trying posting in the WTB forum for a used combo switch. In the meantime you should see if you are getting power base off Section EL-17 of the FSM for the lighting switch. It shows which pins are shorted base on "Off", position "1" and "2".

[tiggs]

So swapped in a known good combo switch and no go. For the mean time until I figure out what is going on, and since I now have a spare switch, I'm going to have fun with solder and jump the connections between each headlight in the switch itself. There can't be too much voltage/amperage going through that thing to matter.