Not trying to hijack thread but for future searches as our symtoms appear similar....

Can we confirm mine are sport lights or aftermarket as after you mentioned the bulbs i looked and i have 9004's installed...your saying they should be 9007's and could just a wrong bulb cause the high beam indicator light to stay on regardless of high or low beam selection.

heres my lights-

 

Champion was right. Auto zone sold me the wrong bulbs! It takes 9004s and they sold me 9007s. I replaced them in the parking lot of the store and all is well. Thanks to all for your assistance.

 

Glad to hear it...I'm hoping mine is that simple lol if not ill just step in and take over this thread

 

If the harness hasn't been diddled, then you need 9007's. The plugs for both 9004's and 9007's are the same, but the pinout is different. Looking into the base of the lamp with the key up, 9004's are pinned, left to right, as common, low beam, high beam. 9007's are high beam, common, low beam. A quick visual ID, if you can see the filaments: 9004 filaments are transverse (from one side of the envelope to the other) while 9007 filaments are axial (aligned with the long side of the envelope).

 

Great! Confirmed..I'll run out and get the 9007s and see what happens before i get crazy on the wiring..

Thanks so much.

 

Please follow-up so future visitors who search might find this bit o' info and know whether or not it worked for you.

Chewgoddit -- you're welcome.

 

Will Do.

 

Ok..so bummer for me...back to the drawing board...9007s will not fit in headlight housing only the 9004's will...

...Parts place (Auto Zone) computer says 9007's are for quad lights and 9004's are for 2 light systems...

...on the path of right or wrong bulbs i just wonder if its possible the headlight housings were changed on my truck at some point and while they only accept 9004's the trucks wiring is for 9007's...

otherwise its back to searching out the various other reasons..grounds most likely...I'll be in touch...i dont get as much time to work this out during the week with work but i'll be out in the cold and dark with a drop light and a meter chiping away at the issue until its resolved.

 

also i notice the wiring diagram in the haynes manual says i should have a black wire for ground but as i specified before thats a no, (red w/orange stipe, purple w/ red stripe, purple w/ white stripe)

While i go through the wiring more if anyone thinks 9007's should be what are in my 99 sport than i gues i could clip and rewire the connector to work for the 9004's...

 

'ight.
Here's the deal, Bailey, your truck is a 99+ Sport model. Those trucks have two bulbs her housing, STOCK. Your truck, however, does not have the STOCK housings, it has aftermarket housings that are not Sport-compatible. So, unless you want to futz around with the connectors, your best method would be finding new housings that are Sport replacements.

Hell, twin bulbs look better anyway.