J

jonmyates

Member

• Jan 12, 2018

• #1

Hello all,

On my 2005 110 I have a strange problem.

The high level break light does not work when I press the break pedal. However, if I turn on the rear window heater or the rear wiper, it comes on and will go off when I brake.

I've checked all visible contacts and tinkered with most cables to no avail. Can anyone shed any light on this?

Regards,

JY

 

Disco1BFG

Well-Known Member

Full Member

• Jan 12, 2018

• #2

Electrical weirdness of this nature is almost always an earth return fault - it works when the other circuits are in use due to be able to earth through them.

Deafeners are renowned for such issues - worth checking all earth straps are present and correct.....

 

Oldseadog

Well-Known Member

• Jan 13, 2018

• #3

As BFG says, it's almost always the earths.
Looks like you got a better earth on the screen heater and wiper (common earth strap) than on the brake light.
Try just linking them up together.

 

J

jonmyates

Member

• Jan 13, 2018

• #4

Thanks both, I'll look a bit deeper!

 

A

agew

Active Member

• Jan 13, 2018

• #5

Similar issues which I’d decided were earthing..... Any easy hints on where vulnerable earths are found that end of the chassis? Thx, A

 

Oldseadog

Well-Known Member

• Jan 14, 2018

• #6

Either on a stud or a screw at the arse end of the chassis.

 

Discokids

Well-Known Member

• Jan 14, 2018

• #7

If you feel flush it's worth getting a length of good cable and suitable connections and running an earth back to either the gearbox / block or direct to battery. Or at least earth everything to the rear of the chassis.

 

A

agew

Active Member

• Jan 16, 2018

• #8

Good advice - cheers both, A