Lights Malfunction? Help Can Figure It Out.

[Dufus]

seem to have developed a problem with the electrical system and the lights. The problem is this :

All the bulbs seem intact and fine

The fuses seem intact and fine

The headlights work and the brake lights

I drive the car and indicate and all seems fine with indicators working. However I apply the brakes and the fog light warning light slowly iluminates on the dash panel. The rear indicators stop working and both rear brake lights seem to flash instead of just the indicators working.

I have pulled out the light assembly cluster at the rear to check the bulbs and when indicating it seems there is a bit of current going to the brake bulbs causing them to light up a little bit.

basically I have no rear indication lights work sometimes, and when I brake all you can see are flashing red lights. The hazards work, but the rear indicators dont do the flashing, only the brake lights. The front ones are fine

Putting the car in reverse also seems to iluminate the fog warning light on the dash.

I have no idea how to track this problem down, so any help would be fantastic. Hope all this makes kind of sense.

[T600]

seem to have developed a problem with the electrical system and the lights. The problem is this :

All the bulbs seem intact and fine

The fuses seem intact and fine

The headlights work and the brake lights

I drive the car and indicate and all seems fine with indicators working. However I apply the brakes and the fog light warning light slowly iluminates on the dash panel. The rear indicators stop working and both rear brake lights seem to flash instead of just the indicators working.

I have pulled out the light assembly cluster at the rear to check the bulbs and when indicating it seems there is a bit of current going to the brake bulbs causing them to light up a little bit.

basically I have no rear indication lights work sometimes, and when I brake all you can see are flashing red lights. The hazards work, but the rear indicators dont do the flashing, only the brake lights. The front ones are fine

Putting the car in reverse also seems to iluminate the fog warning light on the dash.

I have no idea how to track this problem down, so any help would be fantastic. Hope all this makes kind of sense.

Bad earth circuit - the lights are using each other as a route to earth.

[Dufus]

Bad earth circuit - the lights are using each other as a route to earth.

hmmmm so how to track that? havent disturbed anything to cause it. and all the wiring seems shielded

[GT4 BOOSTER]

could be a faulty bulb , ie a single filement bulb instead of a double contact , failing this run an earth wire from the body to each earth wire , this should sort it out, the old ford escorts were notorious for all the rears blinking

[Dufus]

could be a faulty bulb , ie a single filement bulb instead of a double contact , failing this run an earth wire from the body to each earth wire , this should sort it out, the old ford escorts were notorious for all the rears blinking

looked at all bulbs and all seem ok. ie filement in tact and does work in some way. Just not getting why its caused by depressing the brake pedal and fog dash light comes on. There should be a quick way to check this rather than having to mess around all over the car :( boo hoo

[GT4 BOOSTER]

it will either be the pedal switch , a faulty bulb or bad earth somewhere, with electrics nothing is ever easy .

[sotal]

yep - I had the same with a peugeot 306. The headlights came on when you put it in reverse, the indicators came on with the side lights and the brake lights indicated.

It turned out that the rear lights were earthed under the bonnet which was a bit far away and they went through the door hinge so they were wearing out each time the door was opened/closed.

I fixed it by running a big earth wire from a bolt in the boot to the earth wire in one of the rear cluster - instantly fixed everything.

One of the easiest ways to check which part of the circuit it is may be to take all the bulbs out then put them in one at a time until the fault develops??

[T600]

looked at all bulbs and all seem ok. ie filement in tact and does work in some way. Just not getting why its caused by depressing the brake pedal and fog dash light comes on. There should be a quick way to check this rather than having to mess around all over the car :( boo hoo

One side of all of the bulbs is connected to +ve via the switch or other device that controls it. The other side of all the bulbs are effectively connected together, and should be connected to earth. If the earth is broken, then the electricity will find the easiest path to earth and this is usually via another bulb. In your example, it's going back to earth via the foglight circuit's warning light (because there's a connection between the fog light bulb and the fog light warning light. To do this it probably goes via the fog light too, but that may not illuminate as it needs far more current to light it up than can pass through the warning light).

You don't need to trace the problem all over the car, you simply need to make sure that the light cluster is well earthed. Typically the cluster's earth would be the screw fixing it to the bodywork, but if there is any corrosiion where it connects, then that won't be a good earth and the current will find an easier route. As has been suggested, run a good earth from elsewhere and problem will be fixed. If you're doubtful just try a temporary wire back to a known earth, you will see that it fixes the problem and then you can install it properly.

Good luck.

[Dufus]

thanks for this guys, will try and give it a go over the weekend.

[Dufus]

thanks for this guys, will try and give it a go over the weekend.

Thanks guys, thats sorted the problem now. Loose earth wire. Woo hoo all working again.

[GT4 BOOSTER]