Help - Intermittent Brake Lights

[jmcmb]

hi all having problems with my brake lights
they work intermititly bought new switch from dealer fitted new switch and brakes started to bind up (come on) put old switch back in brakes came of but now got the old problem with lights working intermititly
doing my head in bloke at the dealership is just as confused (turbo d40 auto Spanish)

 

[10navst]

Have you tried finding fuse and replacing it or cleaning the actual fuse holder. Could even be a bad earth on engine or body.

 

[Old.Tony]

Are your reverse lights and indicators working properly? If not, then I'd be checking the earth at the bulbs too. Grab one, remove the globe, run a jumper lead from the battery negative down towards the rear and put one multimeter lead in that. With the multimeter set to ohms, touch the other lead to the outside of the globe socket. It should read 0 ohms or near enough. If it reads higher then you've got an earth problem.

This problem could be either in tail light assembly to tub or tub to chassis. Find it, problem fixed.

If the other globes are working ok, there are TWO switches on the brake pedal. Check 'em both, have heard of them failing now and again.

 

[jmcmb]

yep and yep it's like the cruise control is trying to slow the car down maybe I just put up with intermitant brake lights and watch my rear vision mirror!!!!

 

[jmcmb]

but thanks for the input guy's

 

[bods]

if your brake lights aren't working properly then the cruise control won't work either, it's a safety feature so you don't set the cruise and then can't disengage it by tapping the brake pedal. same as if you have a brake light not working, the cruise won't set.

i find it hard to believe that a new brake light switch was causing the brakes to drag, although some people have had issues with accelerating when the brake lights are on (people have noticed this with electronic brake controllers mainly) so that could be why they feel like they're dragging. i'd put the new switch in and check the adjustment of it to make sure the lights aren't stuck on all the time and see if that helps...

 

[jmcmb]

ah but there lies the problem cruise control works perfectly, the brakes were binding up (coming on) after I put new switch in took new switch out put old switch back in brakes are fine just have intermittent light operation. tell ya driving me mad going to the auto electricery guy in the morning let him scratch his head or beat it in to a brick wall I know I have made a big enough indetation on my wall!!!!!!

 

[jmcmb]

and yes I ment ELECTRICKERY.

 

[Old.Tony]

I thought the brakes were self-adjusting? There shouldn't be any hydraulic pressure on the brake pistons until you press the pedal!

Brakes are assisted though, and the system needs to be airtight. Run the engine at idle for 1 minute, pressing and release the brake pedal about halfway through (at the 30 second mark). Turn off the engine, then press the brake pedal. It should go a fair distance in. Release, wait 5 seconds, press again - it should depress less. Release, wait 5 seconds, press again - it should be quite firm and not depress far. If it doesn't go in a fair distance at the start and gradually move out, the system's not airtight and it needs attention.

Also check the vacuum. With the engine turned off, depress the brake pedal several times and then keep your foot on it. Start the engine (keep that foot down). Count to 10 and release the brake pedal and depress it again - it should NOT travel all the way down. If it does, there's a vacuum issue.

If you have a vacuum issue you might also have a turbocharger actuator issue (it will feel like it's rather sluggish compared to what it was). Vacuum is created by a pump near the oil filter on the right-hand side of the vehicle and the vacuum lines pass over the motor to the turbocharger (actually, the round gold widget on the top).

Another test that your actuator is getting vacuum properly: with the engine idling, shine a torch under the actuator. You should see a metal shaft moving in and out about 3-5mm. If it's not, then the actuator isn't responding normally and I'd definitely say there's a vacuum problem.

 

[jmcmb]

thanks for reply old tony all brake system including vacuum & abs check out ok and no not the turbo the brakes were applying as I was driving, changed back to old brake light switch and all ok except intermittent brake light operation. there must be a gremlin in the electrical system some were. still haven't had chance to get to sparky but will have to soon or else I will have more to fix then just brake lights!!

 

[Old.Tony]

It's extraordinary, because the brakes aren't electrically activated - whether the lights work, the bulbs have been stolen, the fuse is blown or some moron has planted several rows of corn across your taillights won't make a whit of difference - you press the pedal, the mechanically operated brakes come on.

That makes me think it has to be something to do with the position of the brake pedal with the new switch affixed, and that the new position (which you would think ought to be the ordinary position) is causing the brake system - which has a problem, because it's not adjusting itself properly - to operate when it shouldn't.

I can't think of any other reason for your problem. If it were triggering the ABS, you'd have less braking, not more - that's the only electrical interaction with the brakes, everything else is mechanical.

 

[jmcmb]

well old tony maybe the moon has planted several rows of corn over my lights and the all mighty one is playing fun and games with me and my vehicle but with the old light switch in place the brakes are fine put the new switch in and the brakes begin to apply them self's.
may be I need to rid myself of this possessed vehicle and get another patrol ute blast the grand kiddies they can walk!!

 

[Old.Tony]

Here's an interesting question.

With the old switch in place, how far from a fixed point on the firewall is the brake pedal, compared to the same measurement with the good switch in place? In other words, does the brake pedal move towards the firewall with the new switch in place?

 

[maulbeagle]

Old.Tony I found the same thing and posted this some time ago regarding my electric brake controller

From http://www.nissan.co.th/en/Innovatio...y/Control.aspx


That conviction lead to Nissan developing their Brake Override System before any other Japanese car manufacturer. The system ensures that, should both the electronic accelerator pedal and brake pedal be pushed at the same time, engine power is reduced, and the brake is always given precedence.

So if the brake switch is faulty (electrically, the car thinks you've depressed the brake pedal) then the acceleration is inhibited.
Exactly the same issue I have if I manually operate the slide control on my Tekonsha Voyager brake controller.

 

[jmcmb]

problem solved, the cruise control switch had been disturbed and the ecu thought that the car was going over speed and thus the brakes were being applied (cruise control switch is above the brake switch the manual shows it in reverse) but thanks every one for there in put

 

[Old.Tony]

Whoa, your cruise control also applies the brakes?

Mine doesn't. I want an upgrade!

 

[jmcmb]

pull your cruise switch out and see what happens!!

 

[Old.Tony]

It won't do a thing. Mine's a 2009 model - no automatic braking. It'll engine brake ONLY if I apply the foot brake (which of course disengages the CC) but the cruise on mine only has eyes for the throttle - it doesn't swing both ways.