Ive been spending the ocasional weekend for months checking all my wiring and earths and i got all my lights working, bright too but my brake lights still dont work, ive checked the resistances between the switch and the light and between the earth and the battery and they seem ok, and the brake switch is brand new and the lights dont work even when u press the button on the switch by hand.

also when the engine is running the "brake" light on the centre aux dash is lit up, any ideas???

and my fog light doesnt work but ive not looked at that yet, but any ideas on that one too??\

thanks everyone

Stick a jumper wire from 12v+ onto the switch. If they don't light then it's earth or the bulb holder or the brake filament on the bulb. (you have tried a new bulb or checked the existing bulb works haven't you?)

No idea what the instrument light is, I have not seen one. Have you got a wiring diagram that includes it?

yeah the bulbs r fine, ive also put a voltmeter across the bulb and theres nothing, the earths have been checked there fine. it could be the bulb holder but the rear lights work fine.

the center aux dash is a millitary thing i caant see it on any diagrams

http://siddall.info/lr/dash.jpg

its the center bit were the fog light swich it, theres a small blackcover and the word "brake" lights up on it, i think i read its something to do with the brake failure switch

The steering wheel appears to be on the wrong side which won't help.

When you say'voltmeter across bulb', do you literally mean that? Cos you won't expect anything from that. Volt is potential difference so you would need to put one probe on the bulb and the other to earth to ve- (assuming negative earth) to see voltage.

Sounds like there's no volts. Sometimes it's good to ditch the meter and just go with a bulb with two wires. Put one to ve- on the battery and the other end where you expect live. This removes the possibility of phantom voltage (that won't support load). Theres a fancy version called a power probe like a pointed screwdriver with a bulb on the handle. I always use this until a really need to get the meter out.




Where abouts are you?

yeah i had one probe on the bulb and the other going to earth, as in the virtual earth on the battery. i seen the power probe but only for mains voltage
yeah thats not my car its the best picture i could find online with the center auxillary console.

The landy is based on the wirral i only get to work on it every so often im at uni in manchester.

Brake light - check there is feed to the switch - it should be on the ignition. the fuseboxes get dirty - I've found the only thing that works is to polish all the holder arms with a wire brush on a dremel. The fuse box may be convenient for changing fuses but the wires don't fit easily - and can fall off if the thing is removed from the column etc.

Brake warning light - will monitor one or more of the following:

PDWA - safety device which joins 2 separate brake circuits and tells you something's wrong when your foot sinks nearly to the floor. Its an electrical switch on a shuttle valve under the drivers floor (on RHD ones).

Excess pedal travel - this is operated by a switch often near the brake light switch on the top of the pedal box (Servo pedals). The intention is to tell you the linings have gone or the brakes need adjusting.

Servo warning sensor - screwed into the servo and looks like an oil pressure switch - but works the other way round.

Around 1980 all but the PDWA switch seem to have been deleted - and that was put on a self check when the starter is operated. Needs a relay for diesels - and possibly others but I think its only diesels as they disconnect everything when the starter is operated. (Had hours of fun working one of those out for a LWB diesel that had started life as a petrol!)

There are few details on the wiring diagrams, some references in the workshop manual - and the military diagram can be some help -(Even shows the heater which is missing from most civilian diagrams)

Final thought - if you have new rear light units the red wires are the brake lights and the green - the side.

Thanks for that, i will check my fuses because the wires going into the fuses dont match any diagram ive seen but i didnt want to be messing with it because everything but the light was working, next time im home i'll take a picture or make a diagram and hopfully someone can shed some light on it

I got them working!!! i found a loose wire in the fuse box, so releived its taking me agers!