Aussieveedubbers · Tech Talk

Tail lights working, brake lights not

https://forums.aussieveedubbers.com/threads/85541/tail-lights-working-brake-lights-not

johnl ·

Having a few dramas....The tail lights are working in the 68 1600 beetle but the brake lights are not. Neither of them.

Had a problem where the low beams weren't working either but now they seem to have come good on their own.

It is a MESS of wiring. Any hints, tips or clues as to what I need to check?

With the advice offered, please understand I am not a guru by ant means so any "just look at the soleniod" may not be helpful without a clue as to where it is situated.

Might be a problem with when I had to replace the brake lines from the master cylinder attachment as per this thread: http://forums.aussieveedubbers.com/viewtopic.php?tid=83163&page=1#pid774442

Have I done something there and IF I have to have a look at this again, I will need to pull the petrol tank out right?

Maybe a trip to the auto electrician for a speedy fix?

Thanks for any help you can offer...

John

Bizarre ·

If you have a multi meter check to see if the switch on the master cylinder is working??

johnl ·

I have a multi meter. Do I need to take the petrol tank out to check that or is there an easier way? Told you I was no guru.....

pod ·

easy without multi meter ,bridge the 2 switch wires if lights work then its the switch ,just take drivers side front wheel off and you can get to the switch on the master cylinder pretty easily,if they dont work check your fuses are all good and maybe clean the fuse terminals,if not fuses check wiring connections in the engine bay

h ·

also give all the earth's a good clean up with wet n dry or alike that will help too when u finally find the problemo

shaihulud ·

To be able to do basic electrical work on a car you will need to have at least two lengths of electrical flex about 2 metres long with a small crocodile clip on each end. Make them in different colours.

You can then get power from the battery or a fuse to check any part of the system.

Carry one in the car and then if you need to, you can connect the positive terminal of the battery to the positive terminal on the coil, to hot wire the car if you are without your keys.

Also get a test light which is shaped like a fountain pen with a festoon globe in it and a pointy end on it and a length of flex and a small alligator clip on the end. You can test all sort of things with it to see if there is power in a circuit. Connect the clip to earth and then poke around at terminals and fuses and see what happens. IF the light comes on you have power there.

With regard to your brake light problem I would recommend as policy from now on that when something like that happens, the first thing you do is clean all of the earth terminals that are connected to that circuit.

You must have followed a car where the indicators turn on when they apply the brakes, or the tail lights turn off, or something weird like that. That is a sure sign of bad earths. the current goes to the easiest place not the required place.

68AutoBug ·

johnl wrote:I have a multi meter. Do I need to take the petrol tank out to check that or is there an easier way?
Told you I was no guru.....


Hi
Don't take the Fuel tank out...lol

You can see the brake master cylinder and brake light switch or switches under the front near the drivers side front wheel..

make sure the wires are connected...

with the key turned on...
and touching the two wires going to the brake switch
the stop brake lamps should go ON...
You will need someone to check the lights...

don't leave the key turned on too long...
the coil will get hot..

LEE



http://community.webshots.com/user/vw68autobug

68AutoBug ·

If Your tail lights or blinkers still work....

The Earth/ground is OK....

otherwise the tail lamps etc wouldn't work...

also check the fuses...

LEE

johnl ·

Thanks for all the very quick repsonses. I took the wheel off and can get to the switch fairly easily. I disconnected the two wires and put them together but no luck. Still not working. I will have a look at the earth connections but I am wondering why both are not working. Seperate earths I would think?

68AutoBug ·

johnl wrote:Thanks for all the very quick repsonses. I took the wheel off and can get to the switch fairly easily.
I disconnected the two wires and put them together but no luck.
Still not working. I will have a look at the earth connections but I am wondering why both are not working.
Seperate earths I would think?
If Your tail lamps are working....

then You DO NOT have an earth problem...
the whole tail lamps blinker is earthed together...

check Your Brake lamps fuse..

Did You have the key turned on when You put the brake switch wires together??

unlikely, but not probable that both stop lamp bulbs have blown..


LEE

johnl ·

I have checked all the fuses and they are fine. I checked the brakes with the ignition on and off and no joy. I checked one the bulbs and it is fine as well. The top connection on the MS wire was not real good but I dont think that is the problem as I put the two together and no good. It is off to the auto elec. I have run out of time as I have other stuff to do. I will let you know what he/she finds.

68AutoBug ·

johnl wrote:I have checked all the fuses and they are fine. I checked the brakes with the ignition on and off and no joy. I checked one the bulbs and it is fine as well. The top connection on the MS wire was not real good but I dont think that is the problem as I put the two together and no good. It is off to the auto elec. I have run out of time as I have other stuff to do. I will let you know what he/she finds.
If You touch both wires together and the lights do not work....
then the brake switch looks OK too...

Just need power to the brake switch...
from anywhere...lol

If You connect the brake switch to a live power source the brake lamps should work every time You use them. regardless of whether the ignition is on or not...

cheers

LEE

beetleboyjeff ·

Check whether you have power (with a test light) to one of the wires to the brake light switch on the master cylinder when you have the ignition on.

The other thing to do would be to run power to the other wire (the one going to the brake lights) and see if they light up then.

At least this way you should be able to work out if the problem is no power to the switch, or no power getting from the switch to the lights at the back of the car.