Low beam headlight electrical problem

[bullguy]

Hi Respected members of GN,
I am facing a problem with my low beam headlights,i tested the electrical connection in the fuse box everything is fine upto the fuse 6&3,relay is working fine but my LB Headlight doesn't work tested the bulbs working fine,High beam works fine rest all works fine.kindly advise me how to find the fault.
Thank you

 

[Mounce]

Relay. Swap the two black relays in the under hood fuse box, if LB's work, there's your problem.

If it is indeed the relay, replace with ACDELCO only. Cheaper relays melt. (ex: Google "headlight relay melted gmtnation.com" and you'll see what I mean)

 

[bullguy]

Thank you Mounce for your reply,as i said earlier my relays are working fine the power is going upto the fuse but not for the weather connector.

 

[Mounce]

Sorry, missed that. I would guess it's a grounding issue then but I'm not sure where they're grounded. That's assuming both lights are grounded at the same point.

 

[Blckshdw]

You can rule out bad grounds (I am doubting this if they went out at the same time) by choosing a known good ground spot for your meter, and testing for power in the connectors that way. If you haven't done this already.

After that, I would suspect damaged wiring somewhere, so you'd have to peel open the loom and inspect the wires. If you undo the bolts in the fuse block, and release the clips around the outside edge, you can lift the block out and get access to the 4 sockets plugged into it to inspect those connections. This will also expose the metal traces that connect the various fuses/relays to those sockets. Look for anything scorched or broken that line up with the 2 low beam fuses.

 

[littleblazer]

Ground a meter at the battery and check for voltage at the low connector. If it's there it's a ground. But looking at the diagram it's a different ground for each. Also the highs share ground. Also check the plug into the headlight assembly. It is possible the connection is faulty there.
So the highs work? If you flash to pass do both come on?

Edit: Make sure the fuse connection isn't spread. There are sometimes issues with that.

 

[bullguy]

You can rule out bad grounds (I am doubting this if they went out at the same time) by choosing a known good ground spot for your meter, and testing for power in the connectors that way. If you haven't done this already.

After that, I would suspect damaged wiring somewhere, so you'd have to peel open the loom and inspect the wires. If you undo the bolts in the fuse block, and release the clips around the outside edge, you can lift the block out and get access to the 4 sockets plugged into it to inspect those connections. This will also expose the metal traces that connect the various fuses/relays to those sockets. Look for anything scorched or broken that line up with the 2 low beam fuses.

Is there any article to open the fuse block
Thanks

 

[Blckshdw]

Is there any article to open the fuse block
Thanks

No there isn't, but one really isn't needed. Once you remove the lid and take a look, it will make more sense. Bolts in the middle, clips around the outside.

 

[bullguy]

sorry for late reply......
i solved the problem by just reversing the connector of my HID ballast..bingo lights are on

 

[pell]

What is the HID ballast? Having same Issue. Thanks

 

[Mooseman]

HID ballasts are for those that have either converted to HID headlights or Saabs that have HID. If you have regular halogen bulbs, then you don't have these.

Common issue if both headlights fail at the same time is the headlight relay/module. Try swapping it with the one for the fan. They both use the same one.

 

[pell]

I did swap the relays, as I had this happen with my older TB. No power to either lamp, sent it to a mechanic. Thanks for the help. Will let you know what he finds.

 

[mrrsm]

Another View and Diagnostic Approach:

And from WWW (Watch Wes Work)... more ideas:

...and MY

Tighten Down THESE Four Galvanized Steel Fuse Block Posts ...SNUGLY: