S13 No Headlights (Motors Work, Running Lights Work)

[vehicle336]

Car: 1990 S13 pop-ups

Issue: No headlights at all, no high-beam indicator light when high beams are turned on. I tested power to the headlight fuses (numbers 7 & 8) in the fuse relay box under the hood (passenger side), no power is reaching those fuses.

What I've checked so far: I pulled every fuse in the fuse box and fuse relay boxes, none of the light-related fuses were out. Also moved around the 3 retract relays just to make sure there weren't any issues there - the lights go up and down plenty fine. I also unplugged the headlight timer assembly to see if it changed anything. Other than preventing the headlights from retracting at all when unplugged, I don't think it's broken but I'm not entirely sure if it also controls the power to the headlights (see below).

I also bought a new blinker/light stalk for the steering column to eliminate that possible issue.

My question: What else is in-line between the light stalk and the fuse relay box under the hood? I'm unclear as to whether or not the headlight timer assembly also relays power from the light stalk to the headlights, or if it is just for the headlight retract relays and the up and down motion of the headlight motors.

Could my issue be with the headlight timer assembly or is there something else at-play that I'm missing?

Thanks ahead of time.

[Rockhoundrob1]

Check the wiring diagram on my post that is about 10 line lower...

Manuals > USDM Cars > 1989-1990 240SX (KA24E) - Nissan 240SX Performance Tuning

Headlight is in section A16, lights- section A1 and E1, Relay#1 (this is the relay that turns lights on and off)= Section D3

I spent 4 hours figuring out why my lights would go up, but not down. Turned out to be the knob on the signal switch.

[Rockhoundrob1]

this is it. scroll to the electrical section. The "sections" i listed above were for a 1989 240SX - S13

Yours should be the Same... check the first link

http://zilvia.net/f/showthread.php?t=431245

[Rockhoundrob1]

just skimming the electrical diagram....

1) check for voltage on the following with the "lights on".

a) Brown wire going to retract motors
b) purple wire going to left headlight
c) red/green wire going to right headlight (or green blue)
d) Check 15A fuse for headlight
e) check retract switch - check voltage at red wire, and light blue wire

If there is no voltage on them, let me know which ones don't have voltage

[vehicle336]

just skimming the electrical diagram....

1) check for voltage on the following with the "lights on".

a) Brown wire going to retract motors
b) purple wire going to left headlight
c) red/green wire going to right headlight (or green blue)
d) Check 15A fuse for headlight
e) check retract switch - check voltage at red wire, and light blue wire

If there is no voltage on them, let me know which ones don't have voltage

I checked the voltage at the fuse relay box for both the 15A headlight fuses, there's no power there when the lights are turned on.

Where are these wires located at that you want me to check specifically? Coming from the switch in the steering column? Post timing control unit? wires going into the headlights themselves?

[Rockhoundrob1]

Each of the wires I gave you with the colors are connected to what ever unit I described.

for example:

brown wire- to retraction motor. if you look at the motor next to the light, you will see a connector. Disconnect the connector and measure the pin that the brown wire goes to.

Purple wire to headlight - disconnect the wire going into the headlight

Retract switch, you will need to get under the dash and try to get to the switch from under- you will have to remove the panel

Just to be SURE... when you measure, you are using the red lead to touch the pin and the black lead to touch chassis ground ....right?

Also IMPORTANT, when you checked for voltage where the fuse plugs in, did you measure with both leads in where the fuse plugs in? (you CAN'T do that) If you stick both leads in each end in there, that may not work because maybe there is an open towards the switch. If there is, you won't get a reading. Just put the red lead onto the pin and black lead onto chassis ground. then move the red lead to the other pin that the fuse plugs into. If you dont get voltage, then your problem is in a wire or unit before the fuse and not after.

Go back and try to see if you get any voltage on any of those points I gave you, then we can isolate the area. BTW, the headlight timer is on the driver side panel just left and in front of the door. you will have to remove the side panel to the left of the brake pedal.

[Rockhoundrob1]

I looked at the wiring diagram again. It's very important that you get the correct reading on the correct fuses. If you do not get any voltage reading on either fuse pins, then we know you have an "OPEN" between the fuse and the battery. The correct wire that comes from the battery is WHITE.

Can you read wiring diagrams? What I am telling you here is pretty basic, compared the other things I told you... see attached file... the 2 fuses have a red arrow. the yellow line is the power going to the fuses. You should get a voltage reading here.

[Rockhoundrob1]

I can't seem to put an image here for you to look at

[Rockhoundrob1]

lets just check the voltage at the fuses like I described. if you are not getting anything, then you have an open wire

[vehicle336]

Each of the wires I gave you with the colors are connected to what ever unit I described.

for example:

brown wire- to retraction motor. if you look at the motor next to the light, you will see a connector. Disconnect the connector and measure the pin that the brown wire goes to.

Purple wire to headlight - disconnect the wire going into the headlight

Retract switch, you will need to get under the dash and try to get to the switch from under- you will have to remove the panel

Just to be SURE... when you measure, you are using the red lead to touch the pin and the black lead to touch chassis ground ....right?

Also IMPORTANT, when you checked for voltage where the fuse plugs in, did you measure with both leads in where the fuse plugs in? (you CAN'T do that) If you stick both leads in each end in there, that may not work because maybe there is an open towards the switch. If there is, you won't get a reading. Just put the red lead onto the pin and black lead onto chassis ground. then move the red lead to the other pin that the fuse plugs into. If you dont get voltage, then your problem is in a wire or unit before the fuse and not after.

Go back and try to see if you get any voltage on any of those points I gave you, then we can isolate the area. BTW, the headlight timer is on the driver side panel just left and in front of the door. you will have to remove the side panel to the left of the brake pedal.

Sorry it's taken so long to get a response going, kids, halloween, etc.

The following was checked with a multimeter and with the "lights on":

Relay switch in-dash:

Red w/blue stripe: ~12v
Solid green: ~12v
Solid red: ~4v

4-pin brown connecter in the light switch stalk:

Turquoise/green: ~12v

Multi-pin connecter in the light switch stalk:

Green w/red stripe: ~12v
Red w/blue stripe: ~12v

(didn't really check the other ones)

Under the hood/Fuse box relay on passenger side:

15a fuses: Zero reading on both.

Headlight 3-pin connector: Zero reading on all three.

Headlight motor connector:

Purple wire: ~12v

Light timer assembly unplugged:

Orange wire: ~12v
Red w/blue stripe: ~12v


Light timer assembly plugged-in:

Orange wire: ~12v
Red w/blue stripe: ~12v
Solid red: ~4v

I hate electronics and because of that I can't read wiring diagrams for shit. They just don't make any sense to me. Let me know if any of this helps. I also have pictures of where I tested everything.

[Rockhoundrob1]

Was any work done on the car before this problem? You should be getting 12V on the fuse posts.

Are you measuring with one lead (red) to the post of the fuse and the other lead (black) to the car chassis? OR are you putting one lead on one fuse post and the other lead on the other fuse post? ( you can't measure this way)

If you really are not getting 12V to the fuse, then you have a broken or disconnected wire between the battery and the fuse. That's why I asked if any work was done on the car.

[vehicle336]

Was any work done on the car before this problem? You should be getting 12V on the fuse posts.

Are you measuring with one lead (red) to the post of the fuse and the other lead (black) to the car chassis? OR are you putting one lead on one fuse post and the other lead on the other fuse post? ( you can't measure this way)

If you really are not getting 12V to the fuse, then you have a broken or disconnected wire between the battery and the fuse. That's why I asked if any work was done on the car.

This car's a clusterfuckistan. It was some kid's "missile" car before I bought it and I'm slowly trying to un-fuck it (ex: the fuel rail was zip-tied on).

The battery was relocated to the trunk before I bought it and what's left is a rat's nest of wires under the hood loosely taped together with electrical tape.

What should I be looking for as far as power from the battery to that fuse box? Is there a connector that could be unplugged?

[Rockhoundrob1]

See the attached diagram...

The wire going from the battery to the fuses to the fuses is white ( but I drew it yellow). You should get 12V here on the fuse post on the WHITE side. If you don't have any voltage, then you will not get headlights on.

No 12V at the fuse says the wire is disconnected between the fuse and the battery

[Rockhoundrob1]

OH boy, that will be fun. Don't feel bad. My son bought a fixer upper and I was responsible for the electrical work, while my son did the body work.

Anyway, Now that I know what happened to the car. I really think it will be difficult to give advice without actually seeing where the wires are ( they are obviously customized). My only advice is to see where the white wire that is at the fuse goes to. My bet is the white wire is cut, or disconnected somewhere. Try to find the white wire and trace it, let me know where it goes...

[gaz_moose]

do the rear lights work?

have you actually got the headlamps plugged in? to the small subloom that goes form the lamp unit to the car loom? its separate to the motor plug.

[1on1]

not sure if your car is stock height or lowered but I know the wiring harness near my front left tire chewed up the wires; one time it ripped my alternator wire.

[vehicle336]

OH boy, that will be fun. Don't feel bad. My son bought a fixer upper and I was responsible for the electrical work, while my son did the body work.

Anyway, Now that I know what happened to the car. I really think it will be difficult to give advice without actually seeing where the wires are ( they are obviously customized). My only advice is to see where the white wire that is at the fuse goes to. My bet is the white wire is cut, or disconnected somewhere. Try to find the white wire and trace it, let me know where it goes...

Final update: Because the battery was re-located to the trunk when I bought the car, the previous owner never ran the headlight power input from where the battery was to a new power source. So I manually ran wires from the battery to the fuse relay box with some butt connectors, shit works now.

Thank you very much for your help, it was paramount to figuring this out.

[Rockhoundrob1]

GREAT! All is well that ends well.

And glad you posted whether it worked or not. Future readers might get pointed in the right direction