Tail Light help.

[lilkiduno]

I am having a weird problem and I haven't had any luck tracking it down. My rear left tail light works for brake, turn signal, running lights, running lights + turn signal (although very dim) but doesn't work for running + brake. With the running lights on when I hit the brake the light doesn't illuminate at all. The Issue on;y seems to be problematic with the rear left light as the Right side responds to everything. I have sanded the ground connection down and that hasn't helped I tried testing the wiring going into the tail light socket but that turned out unsuccessful.

Vehicle Information:

!976 K5 Blazer
350/th350/np203
   

[bake74]

     Very nice to have a detailed report of first your problem, and second of what you have tried to solve the problem.  Thank you.
     You said you "sanded" the ground strap.   Did you check it too make sure it was still a good ground strap with a Ohm/resistance meter ?  (did you check the left side specifically for a good ground on the light assy. itself, the housing ?)  Sometimes, depending on what type of ground strap you have, they can partially separate internally and give you false or sporadic readings.
     What do you mean by you tried to check the wiring going into the light socket, but was unsuccessful ?  Did you check the socket itself for corrosion build up that could be causing weird issues ?
     Since the right side is working fine, you are on the right track that is should be isolated to the left rear only and not a common wire issue that would affect both sides.

[blazing816]

I had similar issue with my back up light, right worked like a champ and the left either didn't light or was super dim. So I just bought a new socket and bulb, wired it in and haven't had a problem since. There are not very expensive so instead of fussing with it I just bought a new one.

[bd]

You have an open in the ground to the left lamp.  What bulb is installed - should be an 1157 or 1034.

[lilkiduno]

When I say I sanded the ground I meant the round for the tail light assembly itself and not a ground strap. As far as trying to test this I was doing this by myself and wasn't able to find anything to wedge/hold my brake peddle down to test the brake circuit with the with the Running lights on. I have thought about just replacing the socket and going from there.

This is the socket here I believe. http://www.amazon.com/gp/product/B005545MRM/ref=ox_sc_act_title_4?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

@bd, I will check when I get home. At work currently, thats why I haven't had time to reply.

[zieg85]

In past trucks I've added a bed ground to the frame.  I've also had problems with the turn signal switch being worn out.

[bake74]

In past trucks I've added a bed ground to the frame.  I've also had problems with the turn signal switch being worn out.

     X2  has worked for me also.

[lilkiduno]

I couldn't find the package for the bulb but I am 90% sure this is the bulb I replaced it with
http://www.oreillyauto.com/site/c/detail/SYL2/1157LLBP/01591.oap?year=1976&make=Chevrolet&model=K5%2BBlazer&vi=1029394&ck=Search_01591_1029394_170&pt=01591&ppt=C0010

Also I went ahead and ordered a new socket to rule that out. Where would you guys suggest running an additional ground strap to the frame on the rear of a blazer?

[bake74]

      On my step side I ran from the frame to the fender support.  On a blazer, attach it to a body panel or inside the fender area, that would be a good place.

[lilkiduno]

Well, I replaced the socket and everything seems to be working fine. Now to stop being lazy and cheap and get a new tail light assembly. I will look into running a grounding strap