I have a 1991 chevy s10 extended cab. a few things went wrond with it all at once. 1.the tail lights went out and i just replaces the bulbs. 2.the speedometer stopped working. 3.the battery is not getting the right charge it needs. the battery and the altanator are both good. whats wrong and how can i fix it?

Hello, if you open the tailgate, there are 2 screws, that hold the lamp in. If you remove these two screws, you can then remove the lamp, and have access to the bulbs. (Make sure you have a new bulb ready). Good luck...coop442000

Obviously you have a short somehow power is bleading over to this circuit. You may be forced to do some hard debuging (i.e wiring diagram, test light isolate the problem on the circuit).

If I were taking a guess I would try the following:
1) Remove the fuse for the taillight
2) If the light goes out I would start looking at the dashboard light switch
3) If the light does not go out then I would start looking toward the rear end of the truck wires that are scouffed, trailer light connections ect.

Hope this gives you a start, needless to say a short can take forever to find.

Yes, those fenders, etc. should be fine. Those two trucks are the same. The body didn't change until 1994 and the part numbers for the two trucks' fenders are identical all the way through 1993. Good luck! I hope this helps.

You have a combination of nuts and screws to remove the taillight assembly.
Type in " e-bay " to your computer and type in the taillight you want, and you will see pictures of them for sale.
I did, and found:
1) 2 screws under/ or alongside the rubber seal that is at the trunk lid opening, and 2) 2 or may be 3 nuts on studs that extend inside the trunk.
Once all these are removed, you will access the bulbs.
God bless your efforts.

go online or local parts store (chiltons) or (hanes) manual good luck

after u check all the bulb try to check the fuses if its ok change the brake light switch which is located front of the brake pedal

I had a similar problem with my 1994 S-10 LS extended cab. Both tail brake lights worked fine. I removed the 3rd brake light cover and tested for voltage at the steel center of the two rivets and found the positive (driver side) negative (passenger side) were good. I checked the two metal strips that send power to bulbs and found the positive side was open. Seems the flared side of the rivet was not making contact with the metal strip. I bucked the rivet with a punch and hammer and it took care of the problem.

Yes it screws in on right side of tramission and you will need a 7/8 inch deep socket to remove it. You may be able to clean the old one once it is removed. There is a little ball thatgets dirty and may you can get by with cleaning it. Good Luck. Ed

i own a 1991 chevy blazer myself but my problem is opposet of yours my back lights stay on well i went underneath the dash board an i look up underneath my steering column an i saw to components one was to my cruise control an the one in back of it was to my back lights an i moved this around an to my surprise my light swork good now but now my speed odometer doesnt not work an my gas gauge am my oil aa water gauge my power windows dont work an niether my a/c or heater defroster im jus wondering if i need to move this component alittke more to the left or right yesterday everything worked hmmmm