Why is dashboard light bulb linked to my brake pedal?

[volvo240student]

Hello,

Every time I press on brake pedal , dashboard bulb for my front lights goes on. If I turn on the lights, light bulb will go on as normal, and then when I press brake pedal, light will go off while my break pad is engaged.

I know that sometimes right back brake tail light will go off, and I would have to remove light bulb and put it back again to make it work again.
Also I dont know if this is connected , but every time I press brake pedal , there is double clicking noise coming from the area around my transmission stick /dashboard area under radio.

Volvo 240 wagon 1993 is my car.
Did anyone has any advice on how to troubleshoot this?
Thank you

[June]

The clicking is the shift lock mechanism. It's likely just getting tired. The light indicator usually means a bulb is out. So likely the car is telling you a light is out. During my 89 740 ownership I had havoc with a taillight on one side until the taillight circuit board was replaced. June

[jimmy57]

Bad ground or poor bulb connection to the contact plates on taillights can cause this. I bet you have a dim brake light and one of the park lamps up fronts comes on when brakes are applied. You may not see it unless it is dark. If the brake light filament and the park light filament meet at the ground on body of bulb. If the ground is not good then the brake light current goes through the taillight filament and then back down the line to the front park light bulb through its filament to ground. This powers the park light circuit and turns on that lamp. I'm surprised the bulb failure lamp is not on.

[volvo240student]

yes, there is issue with contact plates on the right taillight , that brake light goes off all the time. I have to wiggle the bulb holder socket to make it work. But even when i set it up to work, I still get dash light goes on when engaging the brake.

Should I try to replace only bulb holder socket or whole new assembly?

[jimmy57]

You can try sanding the surface on the taillight and the contacts on socket. Use some grease to try to keep corrosion from returning.

[volvo240student]

Bad ground or poor bulb connection to the contact plates on taillights can cause this. I bet you have a dim brake light and one of the park lamps up fronts comes on when brakes are applied. You may not see it unless it is dark. If the brake light filament and the park light filament meet at the ground on body of bulb. If the ground is not good then the brake light current goes through the taillight filament and then back down the line to the front park light bulb through its filament to ground. This powers the park light circuit and turns on that lamp. I'm surprised the bulb failure lamp is not on.

You nail it! It is the failure lamp bulb on dashboard that goes on once I engage brake or turn on light. Silly me was thinking that is regular “ light is on “ dash sign.

I tested the front park light and they don’t go on when I press pedal.
It looks like that passenger side tail light and brake are working all the time. Also one of the connectors melted the tailgate box plastic.

I have switched the sockets with driver side and replace the bulbs to make sure that is not issue.

Is there something I should do to test/inspect taillights assembly or wiring for to see what is other potential issue or just get replacement taillight assembly?

[volvo240student]

Update :

I have replaced tail light assembly and rotate sockets and my brake light on passenger side will still not go on...
Position back light will go on when I turn on lights so there is power getting to the socket.
Do you have any advice on what to look next ?