Rear light failure warning light in cluster (1 Viewer)

[SLC470]

Hi all,

I searched the 100 series forum but found no answer for this issue. I'm still working on this '04 LX470 w/ 150k miles I'm trying to baseline. The "Rear light failure warning light" has always illuminated when the running lights are on and the PO said it was due to the license plate light being out. I replaced that bulb and warning light continues. Today I got around to all the other rear running lights. None of the lights are LED. I've replaced them all with the standard "Sylvania" mini-bulbs from AutoZone (Sylvania Long Life 7443LL Mini Bulb 2 Pack). I had to clean some corrosion on one of the connectors but now all bulbs seem equally bright and responsive. All 4 running lights and 2 licence plate lights look good. I assume the "third brake light" up top (OEM LED bar) should not act as a running light and is off with the lights on but works when the brake is applied.

The PO did convert the headlight low beams to HID (and did a poor job of it). Could ths "Rear light failure warning light" on the cluster be reading the headlight due to the HID conversion? Is the internal resistance from Sylvania bulbs not matching well with the truck computer? Anyone know how to track down which light the truck is detecting as the issue? (or all of them?)

Any advice is appreciated.

 

[SLC470]

Bump to see if anyone has any advice. Thanks all

 

[saucebox]

I assume the "third brake light" up top (OEM LED bar) should not act as a running light and is off with the lights on but works when the brake is applied.

Mine is on all the time as long as lights are turned on (running/park and headlights), and goes brighter with brake application.

 

[SLC470]

Mine is on all the time as long as lights are turned on (running/park and headlights), and goes brighter with brake application.

This is interesting. It would be unusual for my brake light to work but not the running lights on the "third brake light". I could check at the electrical connector but don't want to chase a ghost. Do you know if there was a change '03 to '04? @saucebox Glad to meet another SLC cruiser fan. Thanks for the response.

 

[saucebox]

This is interesting. It would be unusual for my brake light to work but not the running lights on the "third brake light". I could check at the electrical connector but don't want to chase a ghost. Do you know if there was a change '03 to '04? @saucebox Glad to meet another SLC cruiser fan. Thanks for the response.

I don't know anything about a MY change, sorry. Do you still have the factory third light? Mine leaked, so I replaced it with an LED something-or-the-other from an online source. But the function remained the same, and it didn't light up the dash.

 

[SLC470]

I don't know anything about a MY change, sorry. Do you still have the factory third light? Mine leaked, so I replaced it with an LED something-or-the-other from an online source. But the function remained the same, and it didn't light up the dash.

Hey, it looks to be LED from my Googling. I doubt there was a MY change but didn't want to spend a few hours chasing something that wasn't really there. Yeah, this warning light everytime I drive at night is driving me crazy. Does the rear lift gate trim pull up towards the window or down to the tailgate? Trying to take it off now.

 

[saucebox]

Hey, it looks to be LED from my Googling. I doubt there was a MY change but didn't want to spend a few hours chasing something that wasn't really there. Yeah, this warning light everytime I drive at night is driving me crazy. Does the rear lift gate trim pull up towards the window or down to the tailgate? Trying to take it off now.

To change mine out (mine has the whale tail), it was just two screws to drop the light itself out. Mine was simple plug and play replacement, and the wiring was tucked into that whale tail. I didn't have to access anything in the cab or pull any major trim.

 

[SLC470]

Well, as far as the LED third brake bar is concerned it doesn't think it should be on with the running lights:

With brake depressed:

Without brake but running lights are on:

Would this cause my warning light?

 

[jerryb]

It shouldn't.
But

Comparing LC and LX sometimes doesn't work in my experience.
To understand it well, you need your year wiring book.
I'm thinking the rear light indicator includes brake and tail. And that it all related to the tail fuse. Also probably the front blinkers or parking bulbs and sockets, wiring.
You would know of one was shorted though. I don't know if the LC ha dual filoment bulbs or not.
The blinker/parking socket plug shouldn't be affected by an HID, bad install or otherwise. But you never know.

Bottom line, to really figure that out you need your year wiring book. Or download from tis.

The LC third brake light doesn't light up until you press the brake. Earlier years might have. LXs might have also. I can't imagine the whale tail would have an effect of how it lights up or not. I could be wrong though.
I'd clean all sockets and new fuses, new bulbs all around, and verify hid wiring.
Or just verify that he used one side low beam oem input to relay, or wired with both oem low beam without relay(s).
If that doesn't solve it I'd read the book and try to find specific conditions that trigger that LX indicator.

 

[SLC470]

New development:

What the hell were they doing? I don't know if someone has the EWD but I would appreciate the help. These photos are in the compartment with the jack or from the tail light assembly that was removed (it is a continuous passage between them). Why are they splicing the solid green wire that goes to the brake light to another solid green wire that goes in the blue junction seen here and from the blue junction down through a grommet under the truck just posterior to the DS wheel well. I can't tell in which branch point the second solid green wire terminates in but I suspect the 7-pin trailer connector based on the source. I'm guessing this might be causing my "rear light failure warning light"?

 

[saucebox]

I have the book for the 2004 LC, if that would help. You're welcome to borrow it anytime.

I'm just over on the west side of SLC, right by the Frontrunner.

 

[ramangain]

Here's a guess: the OEM wire for the brake signal to the trailer plug is jacked, so they tapped into another known wire. The truck may be seeing an impedance mismatch and reporting a bad bulb. If you don't tow, just undo it.

 

[SLC470]

Saucebox, Thanks for the offer! I may need to take you up on that.

I did what was extremely obvious and pulled the fuse to see what happens. The most concerning outcome resulted. No tail lights when lights are on but brake lights work. I'm assuming the installed remote starter that I discovered after writing this post interrupted the running lights for the tail lights. To fix this (instead of installing it correctly) they just spliced the feed for the running lights from the 7-pin towing connector over to the tail lights. I was thinking I should just leave this remote start system in if it wasn't hurting anything... but now I think I should have it deleted.

This is what it looks like under the dash:

@saucebox Anyone you would trust in SLC with this delete?

 

[saucebox]

Saucebox, Thanks for the offer! I may need to take you up on that.

I did what was extremely obvious and pulled the fuse to see what happens. The most concerning outcome resulted. No tail lights when lights are on but brake lights work. I'm assuming the installed remote starter that I discovered after writing this post interrupted the running lights for the tail lights. To fix this (instead of installing it correctly) they just spliced the feed for the running lights from the 7-pin towing connector over to the tail lights. I was thinking I should just leave this remote start system in if it wasn't hurting anything... but now I think I should have it deleted.

This is what it looks like under the dash:
View attachment 2330992

@saucebox Anyone you would trust in SLC with this delete?

Man, that's a tough one. I don't personally know of anyone. I'd probably hit up the guys at Cruiser Outfitters, or Dustin at State Automotive to see if they had anyone they'd trust.

 

[ramangain]

May The Force be with you.

 

[hankinid]

Apparently, PO really intercoursed the wiring. More fuses than you can shake 2 sticks at in the back.

 

[SLC470]

Yeah, most of that is under the DS dash where the remote starter is. It's a pretty miserable situation though...

 

[SLC470]

FYI:

Reliability of remote start system?

Hey all and thanks for the support in this community, I recently obtained a rig ('04 LX470, 150k miles) and have been putting a good bit of time and money into baselining it (power steering rack, valve cover gaskets, radiator, all low pressure power steering lines, u-joints on the rear drive...

forum.ih8mud.com

 

[rrc swb]

I've had this same issue with the tail light warning coming on when I turn on the lights... I've learned to ignore it since all my bulbs are fine.

I've seen a few people with this same issue and I'm wondering if it's a hidden problem... IDK.