Replacing Tail Light Relay

[Acidic]

I'm having a problem with my lights on my 1991 LS400. When turning on the headlights they turn on fine but the running lights in the back don't turn on, the dash doesn't light up and the cluster will not dim. I'm guessing with these problems I need a relay fixed... maybe the tail light or headlight relay. My issue is that I'm showing that the relays are on the TOP of the junction box which are totally unreachable from below. Does anyone know how to reach the top? I've had cars where the j/b will swing down or something like that but I don't see any way to make that happen...

[ROYT]

I'm having a problem with my lights on my 1991 LS400. When turning on the headlights they turn on fine but the running lights in the back don't turn on, the dash doesn't light up and the cluster will not dim. I'm guessing with these problems I need a relay fixed... maybe the tail light or headlight relay. My issue is that I'm showing that the relays are on the TOP of the junction box which are totally unreachable from below. Does anyone know how to reach the top? I've had cars where the j/b will swing down or something like that but I don't see any way to make that happen...

Did you check first for the popular fault of breaks in the wiring in the boot[trunk] hinge?

[Acidic]

I'm having a problem with my lights on my 1991 LS400. When turning on the headlights they turn on fine but the running lights in the back don't turn on, the dash doesn't light up and the cluster will not dim. I'm guessing with these problems I need a relay fixed... maybe the tail light or headlight relay. My issue is that I'm showing that the relays are on the TOP of the junction box which are totally unreachable from below. Does anyone know how to reach the top? I've had cars where the j/b will swing down or something like that but I don't see any way to make that happen...

Did you check first for the popular fault of breaks in the wiring in the boot[trunk] hinge?

Yes yes it was...

Does anyone know how to test the relay as well? I suppose it could also be the headlight switch as well.

[ROYT]

The junction box with the tail light relay does swing down,

I think there is a clip at one end, but it's so long since I looked i can't be sure.

Definitely swings down though!

[Acidic]

The junction box with the tail light relay does swing down,

I think there is a clip at one end, but it's so long since I looked i can't be sure.

Definitely swings down though!

ok, I'll look a little harder... it seemed silly that lexus owners would have to lay upside down on the floor to replace fuses...

[VBdenny]

If I'm not mistaken, the headlight operate off a circuit breaker and the rest of the lights are fused. It is not uncommon for headlights to work on a car while the rest fail to illuminate. This is the first time I have heard of this problem on a Lexus. I have had the same problem in the past on both a Buick and Cadillac and in both cases, it was a defective headlight switch. For what it is worth.

[Acidic]

If I'm not mistaken, the headlight operate off a circuit breaker and the rest of the lights are fused. It is not uncommon for headlights to work on a car while the rest fail to illuminate. This is the first time I have heard of this problem on a Lexus. I have had the same problem in the past on both a Buick and Cadillac and in both cases, it was a defective headlight switch. For what it is worth.

There is a "taillight relay", I found it on sewell, it is also common to Toyotas... Here's a couple more hints... When going to the first position on the stalk that would turn on JUST the running lights and dim the dash I can hear a relay operating in the fuse box area. I don't know what relay but it seems like the stalk is doing something when I click over to running lights...

Does anyone have a troubleshooting flow chart? Like what you'd expect in factory manuals or a wiring diagram? I don't want to throw parts at something that should be easy to troubleshoot

[VBdenny]

I would take a stethescope (engine type) and put a piece of electrical tape over the end then probe around inside the fusebox placing the sensor on the relays until you locate the one making the noise. Then I would go to the junkyard and dig around in Toyotas to see if I find the same one. You might get lucky. Wouldn't cost you a thing (well maybe a couple bucks for the relay if you are honest).

[Acidic]

I would take a stethescope (engine type) and put a piece of electrical tape over the end then probe around inside the fusebox placing the sensor on the relays until you locate the one making the noise. Then I would go to the junkyard and dig around in Toyotas to see if I find the same one. You might get lucky. Wouldn't cost you a thing (well maybe a couple bucks for the relay if you are honest).

Not a bad idea... junkyards are hard to find in New England but I think there are a couple in Mass...

[VBdenny]

I guess it is different in Virginia and Carolina since we have junkyards all over the place. although I am in NJ right now, I expect to be back in Tidewater friday and I might go down to a yard this weekend so if you find out which relay, I'll look and see if I can find one.