Taillight Control Relay port 1 - no signal (1 Viewer)

[attaboy]

Late 1995 Toyota Land cruiser.

Issue:
Dashboard backlight was not working. Was an issue from a while ago that I was working on, but put on the back burner while I worked on other issues.

Recently tail light stopped working. (Brake light and harzards work)
Light bulbs are not blown.
Tail fuse is grounded on both sides with headlights on and off.
Old relay was working, but replaced, and new relay is tested and working.

Port 1 for the tail light control relay does not show ground or power.

L1 light retainer relay looks like it connects to port 1? Could this be causing it? I do not know where it is located.

 

[Rusty Marlin]

You disconnected the battery before all this, right?
With the headlights off, the only path to ground for the fuse is through the lights.
Did you pull the fuse?
If yes, are looking for a ping between TLR 3 and Fuse 1? if this is where are you are getting the ping, you have short between the tail light relay and the fuse block.
If no, then you are picking up the ground on the far side of the lights.

TLR port 1 should show a path to ground only if the headlight switch is on. if no ping with switch on you need to look at the switch, or a break in the wire.

Do you get continuity across the switch when its "on"?

 

[Squash]

You might also check the big connection under the jack in rear quarter panel. Looks like you are in a road salt state and this commonly causes shorting or at the very least a nice blue copper oxidation.
Look carefully at this location as a wire may also be broken.
If you have trailer wiring isolate this as well.

 

[attaboy]

From the TAIL RELAY, I jumped ports 2 and 3, and the dash backlight and tail lights started working!

A little confused about what this means.
Pretty sure it proves I don't have any broken wires or shorts though.
Would the issue be down path 1 of the TAIL RELAY?

Port 1 I thought is an output, so not sure how that could be a problem? (It outputs 14V to port 8 of L1, which is what the EWD says it should be)
Relay is new from toyota, and tested.

 

[jonheld]

Pin 1 of the tail lamp relay is the switched ground through the stalk that fires the relay. With the relay removed and the light switch in the TAIL or HEAD position, you should get a good ground there. If you're not getting a good ground, then you can bypass the light retaining relay in the passenger kick panel. If that doesn't work, then you could have a faulty stalk switch.