One Headlight isn't working - Driver Side Fuse Keeps blowing

[kevboost7]

Hey guys, need help figuring out why my driver side (RH) fuse 15amp keeps blowing. The Driver Sides Headlamp is out, i replaced these a long time ago with LED ones that were working for 1-2 years. Now, the driver side light is out and i traced it back to a broken fuse. I replaced the 15 amp fuse in the engine bay and as soon as i flip the headlight on, it blows the new fuse. Any idea what's going on?

[GTSBoy]

39 minutes ago, kevboost7 said:

as soon as i flip the headlight on, it blows the new fuse. Any idea what's going on?

That's a short. Find the short. It will be somewhere between that fuse and the headlight. Start by removing the plugs from the back of the headlight and dimmer switches, and measure resistance to earth. Supply side (power from the fuse) should have none. The other side should have resistance compatible with whatever globe(s) is there (which is relatively easy to say for a normal globe, perhaps not as easy to say for LEDs). Anyway, if you have very low resistance, you defo have a short. Then you just have to run the wiring like you're running the bowel of a dog (on the operating table) that has swallowed something it wasn't supposed to.

[Duncan]

Just note that when trying to find a short in a globe power supply, it is best to disconnect the globe as it will allow current through to earth. With it unplugged it is easier not to get confused.

Also with the r32 wiring, the high beam has 2 power supplies (one when you push the switch forward and the other when you temporarily pull it back; so if it is the high beam blowing you will need to trace both circuits

[kevboost7]

Man, you guys are like an all knowing encyclopedia.. how do you guys know how to fix everything??

but thanks. i will try to trace this wiring today. What is this globe thing you are referring too? Globe Power Supply? Are you referring to the light bulb?

[Duncan]

Sorry I think that must be another language thing, globe = light bulb

[kevboost7]

Hey guys, I'm reviving an old post but I'm finally getting around to working on this now.

I removed the battery to get a better look at the wires and i traced the wires from the headlight to the fuse box in the engine bay, but the wiring looks fine? The wiring for the R/H headlight is 3 wires and then is bundled up with the large diameter wire that goes underneath the fuse box. I didn't take it apart yet.

I know you said that its a short circuit somewhere between the fuse box and the headlight. But could it be the headlight switch on the dash?

Also, i pulled out my multi-meter and set it on the Ohms, but i'm not sure where to put the negative probe and the positive probe. 

 

 

[MBS206]

1 hour ago, kevboost7 said:

Hey guys, I'm reviving an old post but I'm finally getting around to working on this now.

I removed the battery to get a better look at the wires and i traced the wires from the headlight to the fuse box in the engine bay, but the wiring looks fine? The wiring for the R/H headlight is 3 wires and then is bundled up with the large diameter wire that goes underneath the fuse box. I didn't take it apart yet.

I know you said that its a short circuit somewhere between the fuse box and the headlight. But could it be the headlight switch on the dash?

Also, i pulled out my multi-meter and set it on the Ohms, but i'm not sure where to put the negative probe and the positive probe. 

 

 

Negative probe should be on the cars chassis.

Positive on the wire.

 

Start as said above by unplugging everything (unplug the lights, and switches.

Now at the switch, there is a wire from the fuse, to the switch, so out your positive on that terminal. It should read open circuit. If it reads something, especially a stupid low value, the short is somewhere between the fuse and the switch.

If that's fine, now put the positive probe on the wire that goes to the headlight (at the switch plug). If it reads stupid low, the fault is from the switch, to the headlight.

 

Another quick test, is take the whole LED light setup from the left, and plug it into the right side, does it still blow the fuse? If you put the right hand side led light setup on the left hand side wiring, does the left hand side wiring now blow? 

If the blowing fuse swaps from right to left doing this, your LED lights are the issue.

[kevboost7]

I figured out what’s wrong. It’s something to do with the high beam wire short circuiting. When I measure the continuity with a multimeter on the headlight socket connector it gives me a continuous beeping noise when I put it on the ground socket and also on the high beam socket. 

On the passenger side of the car (working side), it’s only beeping when the probe is on the ground socket. Which makes sense.  So that means it has something to do with the high beam power supply for the drivers side. How do I trace that? Is it the turn signal lever malfunctioning? The one that also controls the high beam and low beams. 

[MBS206]

4 hours ago, kevboost7 said:

I figured out what’s wrong. It’s something to do with the high beam wire short circuiting. When I measure the continuity with a multimeter on the headlight socket connector it gives me a continuous beeping noise when I put it on the ground socket and also on the high beam socket. 

On the passenger side of the car (working side), it’s only beeping when the probe is on the ground socket. Which makes sense.  So that means it has something to do with the high beam power supply for the drivers side. How do I trace that? Is it the turn signal lever malfunctioning? The one that also controls the high beam and low beams. 

Read my post above. It tells you what to do.

[kevboost7]

21 hours ago, MBS206 said:

Read my post above. It tells you what to do.

I did read your post, a few times actually. 

 

Done. Followed this step. [Negative probe should be on the cars chassis.

Positive on the wire.]

 

Did this partially.. now that im reading this over, i only unplugged the LED lights. [Start as said above by unplugging everything (unplug the lights, and switches.]

When you are talking about the switch, you're talking about the knob thing on the right side in the drivers seat right? If so, i need to take that apart?  [Now at the switch, there is a wire from the fuse, to the switch, so out your positive on that terminal. It should read open circuit. If it reads something, especially a stupid low value, the short is somewhere between the fuse and the switch.]

At this point are you referring to the connector by the headlights?  [If that's fine, now put the positive probe on the wire that goes to the headlight (at the switch plug). If it reads stupid low, the fault is from the switch, to the headlight.]

Did this. I can confirm that the LED lights aren't the issue [Another quick test, is take the whole LED light setup from the left, and plug it into the right side, does it still blow the fuse? If you put the right hand side led light setup on the left hand side wiring, does the left hand side wiring now blow? 

If the blowing fuse swaps from right to left doing this, your LED lights are the issue.]

[GTSBoy]

You have found the problem. The wire from the switch to the HB is shorted to earth. Now you have to physically find it and replace it.

It won't be the switch, although following the steps above (and yes, where you ask, that is the light switch on the RHS of the binnacle) will rule it out for sure. Or not, if perhaps the switch has melted. But there's no route to earth inside the switch, so I can't see how it would.

[MBS206]

The switch part, is the switch you use to turn the lights on and off in the car.

 

The test I had was to determine where in the line it is, but on a quick rethink, if it's only blowing when you turn the switch on, then it's the wire from the switch, to the headlight that's got the short.

Now it's a case as GTS said, of physically finding the fault.

The fault could be:

 metal has broken through the loom. Known as a rub through. Places to check: anywhere the wiring has been messed with in the car, particularly firewall grommets if extra cables have been passed through.

Check the inner guard linings, you might be rubbing through with a wheel, particularly if the vehicle has been lowered.

Also check for anywhere there could be high heat, especially if heat shields are missing.

Double check any wiring at the head unit too if someone has messed with the headlight wiring to pick up a feed to dim the headlight at night.

You could also just have really old cabling that is literally falling apart, though, this is more likely in Euros than in an old Nissan in my experience.

[kevboost7]

I took apart the dash and found this strange 2 pin connector. it dosen't seem like its factory or oem, any clue on why someone would add it and where it might have been connected too?