VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt 31 wiring question

Howdy,

When I apply the brake pedal on my 31 - the dash lights come on. When I release the brake pedal the lights go off.

Is this normal or is something wrong?

If something is wrong- where should I look to correct.

thanks

No, that is not normal and it sounds like the dash light (there is only one) might be wired incorrectly on the back of the light switch. There is a brake light switch on the left frame rail that is activated by a lever on the brake cross shaft. When the brake switch is activated, only the brake light should come on. The dash light should only come on when the light light switch is either in the "park" or "on" position.

okie dokie,

will check and see if I inadvertentely moved the wires around when we got it started last year.

Checked out the light switch. The wire from the dash lamp is connected to the lighting switch at the 4 o'clock position. Where shoudl it be attached?

I looked at an instruction for wiring sheet from YNZ. It says dash light to R on light switch. It also says tail light to R on light switch. there is a diagram and it appears to be about 4 o'clock like you said. I tried to see what is going on behind my dash but with bifocals I can't see anything if I am too close to it.

The dash light is wired to the third terminal from the top right of the light switch looking at the switch from the right side under the dash. This is the terminal that is just to the right of the blind terminal at the bottom of the light switch.

The wire going to the tail light is connected to the same terminal that the dash light connects to and this is a cold terminal. The wire that goes to the brake light switch is connected to the "horn" terminal on the light switch and this terminal is hot.

You could also check that the tail / stop light globe is the correct type and fitted correctly. If there is a single contact globe in a double contact socket it will cause that problem by shorting the 2 circuits together.
Tony

ah you got to love old cars

Checked out all wire connections at the headlamp switch and they are all correct.

Checked out all lamp switch positions and operations they are all correct.

The problem (dash lamp coming on when brake pedal is depressed) has vanished.

when brake pedal is depressed the only thing that lights is the brake light-tried it with igniton off, light switch in both postions and car running.

can not duplicate the problem.

took car out for short (25 mile run) to see if the problem would reoccur -it did not.

Everything is back to normal. Seems I might have an intermittent problem-maybe with the light switch?

Cool, and let us know if the problem happens again. It sounds like you are getting feedback from somewhere. It could possibly be the light bulb too as Tony suggested.

hi guys and thanks for all the great help.

Neither the wiring nor the bulbs have been changed or altered in years. Every thing seems to be working fine now.

What is "feedback"?
What causes it?
How does one eliminate it?

One thing that hasn't been mentioned is a poor ground at the tailamp assembly can cause this problem. The current goes from the brake light filament to the socket and if the socket isn't grounded, goes from the socket to the tail light filament and finds its ground through the dash light. This could be intermittant.

George

Very Astute George Eagle!
A reminder, look for those kind of problems where there is a commonality (where both circuits are very near each other) many of these mystery happenings are caused by this exact condition. Like water flows to a lower point, electricity flows to any point of conductivity available in order to return to the negative post.

How does one go about testing to see if the taillamp assembly has a poor ground?

Never had the problem before. What might cause a bad ground all of a sudden?

Corrosion of the bulb base, the socket, the socket to lamp assembly, lamp assembly to bracket, bracket to fender, fender to body in somewhat decreasing order of probability.

You may not be able to test for a poor ground while it is operating correctly. If it happens again, have someone observe the tail lamp while you operate the brake pedal. A poor ground will show little or no light from the tail light. When you see a car at night that loses its tail light everytime the brake is applied, it is a poor ground to the assembly.

George

thanks a bunch.

Next time it happens will check it out

Hi guys ,
Of course I can't get the problem to resurface.
Check out everything this morning.

Examined all wires from stop switch to tail lamp buckets. Wire looks perfect and brand new. No breaks, crimps or wear

Removed both tail buckets and cleaned up and looked for any damage (non seen)

Did notice that I have a variety of different bulbs in the units. The passenger side has S63 in both tail and stop lamp sockets. Both of these are very bright. The drivers side has a T89 in the tail lamp (which I think is a 12V bulb and this bulb is very dim) and a larger bulb (number looks like 6v20/5W on it) in the stop socket.

What should I be using in the various sockets.
My old notes are all over the place I have 1129 or 87 for stop and s63 for tail lamp.

Any advise would be appreciated
Thanks

I don't know the correct bulbs, sorry.

But I DO KNOW a 12 volt bulb in a 6 volt appliation will be a very 'dim' light.

Same idea as using a 12 volt battery cable in a 6 volt appliation. The 12 volt cable won't carry enough juice. Consequently a 'hard' start.

I presume the same 'idea' happens using a 12 volt bulb where it should be a 6 volt bulb.

Bill.

The correct bulb for the tail light is a number 63. The correct bulb for the brake light is a number 87.

Number 89 is a 12 volt bulb, therefore it would be very dim on a six volt system.

skip. as usual thanks

Took the S63 that was in the passenger side stop light socket and put it in the drivers side tail lamp socket. Now both tail lamp bulbs are the same brightness.

Does the #87 bulb for teh stop light have a letter in front of it.

Reason I ask is almost every bulb I have has either a S a T a TS or a P in front of it.

We went from small problem to dead car.

I put teh s63 back into the stop lamp socket of teh passnegers side so I at least would have stop lights until I can lcoate the correct bulb.

Then botht the stop and tail lamps would come on when I put the light on.

Now I get nothing - no lights and no horn and of course no ignition.

Where do I start to look for teh problem?

Everything was taken apart. cleaned and reinstalled. Seems to be working fine now.

Cool! Don't touch a thing and hopefully the lights will keep working until something else goes wrong! ha ha!