Hello people,

I used to be an avid user of VW forums but now alas I have a Disco 97 300tdi manual.

Loving it. only 106,000 and in perfect condition - well almost. I think the engine or gearbox mountings need changing as its a bit clunky - advice taken... anyway more to the point as this is driving me a bit mad - several hours mad

Now I cant be 100% sure but I think this happened when I hooked up my trailer.

Basically neither brake lights work.

So this is what I have tested...

I checked the switch - all good, voltage there and going through it as it should be.

New bulbs

Checked the voltage to the rear light assembly (with it removed and the connection pulled out) its seems to work, 11.5 volts comes through when the pedal is depressed.

But alas when you connect the wires to the lights and then press the brakes - the voltage disappears, in fact is reads negative a tiny bit.

Obviously something wrong here.

I tried a few things to be sure - I tried bypassing the brake switch (shorted it) still nothing - I tried disconnecting the trailer electrics, no change. Nothing is corroded or faulty - all looks good.

I even checked that the connection in the bulbs are not faulty by connecting the 12 volts from side lights to the brake lights and the brake lights come on straight away on the side I was testing.

What ever the problem is, its affecting both sides as neither work, but the voltage is there when the brake is pressed - until you connect them up. Then nothing.

could it be a earth somewhere? but all the other lights on the car are working fine.

Help! - anyone got any ideas? or anyone want to swop an old kombi for a discovery with dodgy brake lights.... only kidding especially with the cold weather coming in the next few days!

All info very much appreciated.

Dozza

 

Another thing I noticed which may or may not have something to do with it...

My abs doesn't seem to be working - checked the all the fuses. may be related...

 

What year is the truck, who's trailer wiring kit have you installed?
As for the ABS, why do you feel it is not working, are any of the other brake warning lights on?

 

Hey, I am a new Disco owner and Vw nut. I just went thru with all my brake lights would not turn off. I found that there are 2 switches on the brake pedal. I first saw the one and it was ok but right above that one was another one, weird but I got it fixed

 

Hey Mike,
1997, not sure who's trailer kit? only had the truck a bout 3 weeks.

ABS - skidded a few times and no ABS - just a plain old skid...

No warning lights

Voltage coming at the back when the pedal is pressed but disappears when its connected!

Any ideas?