1993 Toyota Running Lights Won't work
 

Howdy y'all,
I have a 1993 Toyota pickup, 22RE, with a 4 inch lift rollin' on 33"x12.5" M/T. Recently I took her off roading like I always do but when I went to turn on my dash lights they wouldn't turn on and neither would my running lights. I checked the fuse box inside the cab and every time I go to turn on the running lights, the 15A fuse blows. I looked at the light sockets and they are clean with all wires attached, I replaced the relay above the fuse box and it still blows fuses whenever I try to turn on the running lights. No other fuses are blown and the headlights, brakes and turn signals work. I'm stumped on what this could be. Any help is appreciated.

Hmm. The fuse blows every time. What could it be?

You have a short from your "Tail" circuit to ground. Somewhere. Replacing the Taillight relay was pointless; it's upstream of the fuse.

First, I'd pick up one of these "fuse circuit testers." https://www.harborfreight.com/automo...ter-67724.html Otherwise, you'll go through a whole box of fuses before you ever find the problem. I've never used one, but they supposedly "maintain protection" for the circuit, so they must have something to limit the current to 30amps. (Your multimeter has a fuse to protect the ammeter circuit, which fuse you will just blow instead.) Don't go crazy; allowing 30 amps flow through a short somewhere can start a fire.

All your panel lights, tail lights, clearance lights are on the same circuit and hard to isolate. (You could try turning the panel dimmer all the way to dim; if your current drop suddenly drops from the maximum your tool passes, it suggests the short is in the panel lights.) While it is possible you have mysteriously created a short in the panel (vibration?), it's much more likely you've damaged some exposed wiring underneath as you were bouncing over the rocks. You could try carefully examining the wiring underneath. You might need an assistant to watch the tester as you delicately move the wires around.

Better yet, get a wiring diagram for the circuit (I don't have easy access) disconnect all of the loads on that circuit (unplug the cluster/dash lights, remove all the running light bulbs) then pull the fuse and check for continuity to ground with the multi meter that you should already have (it's a very important multi purpose tool). if you see a ground and you are sure all of the branches of the circuit are disconnected from their loads you have a short and you will need to go thru the diagram disconnecting the wiring harness one connector at a time until you find the one that breaks the continuity shown on your meter then follow that branch until you find the short.

Diagram for 95 4runner
 

I'm not sure if this will open for you or not and it may be very different than yours anyway

If your 93 is like my 92. Crawl up under the passenger side rear, and inspect the main wiring harness that runs to the rear. The problem might even be staring you in the face once you get up under it, and take a look. Take a good look at the wires that go to the tag light, and the bumper mounted tag lights.

I forgot to mention, if you have trailer wiring check that out. probably 90 percent of the running light issues I have troubleshot in the past ended up being shorts or breaks in the harness for the trailer plug.

Stop replacing parts unless you are absolutely sure they are bad and that replacing them will fi the problem. Understand what is really causing the problem. Toyota parts are bullet-proof. Problems are often caused by bad connections - like when people add trailer harness tat often has BAAD connectors - or poor maintenance.
So. Check ALL connections / wiring, etc.