Running light out NEED help

I have a 99 xtra cab Tacoma TRD and my inspection is due this month. Noticed I had had 2 running lights out in the last couple weeks so I picked up bulbs for each.
Replaced the front driver side which was burnt out and when I checked the back passenger side it was not burnt out.
Replaced the bulb anyway and it still did not work. Check the wires near the tail light assembly to no avail.

Doesn't anyone have any ideas on what it could be? Truck has about 120k miles
Electrical is not my thing by the way.

 

Socket might be corroded .

Correct bulb or defective ?? I know I tried using the wrong one at times not paying attention

Trailer converter box ?? They love to cause problems.

Broken wire someplace in the harness

 

Everything looks to be pretty clean and the bulb looks the same but like I said the old one was not burnt out.
Last time I had an issue with the trailer light harness( I think that's what you meant by converter box) on a different truck it blew the fuses and I had no lights whatsoever.

It doesn't seem likely to me that I wire broke inside the harness but like I said I'm not an electrician.

 

You check all of your fuses? Any other lights of the assembly working? Check the outlet with a volt meter.

 

Every other light on the truck works except the rear passenger side running running light.
How many volts should it have running to it?

 

That im not sure of probably 12 i would assume

 

12

 

I'll try that later on today hopefully. Thanks

 

Try the the plug adapter also that the headlight assembly plugs into.

 

A lot of the passenger tail light is fed from the driver side light. The wires are routed underneath the bed below the tailgate. You could easily have something damaged here. I still suspect the trailer harness though. I've replaced mine twice and there are still lingering issues, mostly due to moisture in the trailer plug. I have LEDs though, so they are more sensitive to electrical voltage changes.

 

Your probably right I dont have a first gen. i was just trying to help by stating some things that it could be.

 

I had the exact same issue. What fixed it for me was connecting the drivers side running light to the broken passengers side light. I believe that on the first gens the two running lights have 2 separate wires running from the fuse box. With them connected to each other they work fine now. The only issue I have is keeping the socket on the truck nice and clean.

 

Having similar issues with passenger side lighting, but only if I hook up a trailer with the light harness. Voltage reading from the plug on the truck shows a five volt drop in voltage for brakes and turn signal on passenger side. Lights work fine with nothing connected to plug. Going to try and replace plug and see if that helps.