Electrical. How to Diagnose this?

[10G]

This has been happening on & off for a few years.

The stop light fuse blows. When this happens, the ABS, Traction Control Off & Lost Traction (squiggly lines) lights light up. Cruise control is also disabled and the Stop lights don't work.

I've spent a few hours looking into this problem over time and never found anything.

I can replace 3-4 fuses in an hour then the problem may not show up again for another 6 months.

Does the 2013 Y61 have a stop light switch? Could it be this?
As the fuse is labelled 'Stop Lights' I always think it must be the lights, but could it be something wrong with the ABS and/or traction control wiring?

The stop light fuse is 5amps. I've thought I could place a lower current fuse inline with the stop lights, one per side and see if 1 or both blow before the 5amp fuse blows.

Any other ideas???

[the evil twin]

Have you disassembled the Trailer Plug (and loom) and checked for squished wires, loose connections corrosion etc?
Probably 75% of all 'stop light' issues are due to the trailer plug (if fitted)

Next step would be drop the light assy out on each side and check them for corrosion etc and lastly the door mounted lamp

All those warnings (ESC, ABS etc) are because of the blown fuse

[10G]

Have you disassembled the Trailer Plug (and loom) and checked for squished wires, loose connections corrosion etc?
Probably 75% of all 'stop light' issues are due to the trailer plug (if fitted)

Next step would be drop the light assy out on each side and check them for corrosion etc and lastly the door mounted lamp

All those warnings (ESC, ABS etc) are because of the blown fuse

Thanks ET, I'll do that on the weekend.

I hopped in the truck at lunch time. All those lights were off. Got to the first stop sign, lights still off, released brake pedal, lights came on. Hmmm.

[the evil twin]

Thanks ET, I'll do that on the weekend.

I hopped in the truck at lunch time. All those lights were off. Got to the first stop sign, lights still off, released brake pedal, lights came on. Hmmm.

I assume it is fuse 14 that is blowing?... if it is that Fuse should be 10 amps not 5 according to my wiring diagram

That sucker goes to a few different bits of kit.

IIRC there are two switches on the brake pedal, one is for the lamps the other is for the cruise

[10G]

I assume it is fuse 14 that is blowing?... if it is that Fuse should be 10 amps not 5 according to my wiring diagram

That sucker goes to a few different bits of kit.

IIRC there are two switches on the brake pedal, one is for the lamps the other is for the cruise

Yeah, I'll see if it's numbered. Sometimes the cruise doesn't lock in and I have to tap the brake pedal for it to kick in. Wonder if all this could something as simple as readjusting the brake pedal??? Although that wouldn't make fuses blow.

[the evil twin]

Yeah, check which fuse and also that it is the correct rating.
5 amp is too low for brake lights I reckon so maybe it was inadvertently changed to an incorrect rating.
Each bulb will pull 2 amps plus the eye level door plus any other repeaters you have.


Now, the reason you have to tap the brakes for cruise to engage is that there is an error detection parameter that will not allow for the cruise to engage until there has been at least one brake application... sooo... every now and then when you happen to be in a rare situation where you start the car and accelerate up to speed without touching the brake the Cruise won't engage.

They do that so the system knows that if ,in normal operations the brake is depressed the Cruise will know it and immediately disengage.
If the cruise didn't detect that state then it would be possible for you to be braking and the cruise to be applying throttle.

Thats why there are two switches on the brake and a third on the clutch if it is a manual.

[MudRunnerTD]

Reading your issue i immediately also thought 5amp was too small and was surprised it was only 5amp. Also Trailer plug would be the first place to look i reckon. So often the fault.

@ET you know stuff mate. I learned today. Thankyou.

[10G]

Yeah, check which fuse and also that it is the correct rating.
5 amp is too low for brake lights I reckon so maybe it was inadvertently changed to an incorrect rating.
Each bulb will pull 2 amps plus the eye level door plus any other repeaters you have.


Now, the reason you have to tap the brakes for cruise to engage is that there is an error detection parameter that will not allow for the cruise to engage until there has been at least one brake application... sooo... every now and then when you happen to be in a rare situation where you start the car and accelerate up to speed without touching the brake the Cruise won't engage.

They do that so the system knows that if ,in normal operations the brake is depressed the Cruise will know it and immediately disengage.
If the cruise didn't detect that state then it would be possible for you to be braking and the cruise to be applying throttle.

Thats why there are two switches on the brake and a third on the clutch if it is a manual.

Thanks ET. I'll pull all this apart over the weekend.

Lucky I live in the bush, I can drive around without brake lights.

[10G]

Thanks everyone fro the help.

I found the problem. Drivers side rear light, the stop light and 0v wires had rubbed through and must have been shorting out now and then. And yes, it was near some trailer plug wiring.

Thanks again.