82 euro..NO BRAKE LIGHTS!!!!
08-30-2006, 10:13 PM
#1
Burning Brakes
Thread Starter
82 euro..NO BRAKE LIGHTS!!!!
Following my Nephue today noticed no brake lights !! got to his house and we checked fuses,bulbs and wires all good............. so were is the brake switch?
or any other sugestions?............
or any other sugestions?............
08-30-2006, 10:28 PM
#3
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Hi Tom - The last time this happend to me I replaced the brake master cylinder, which came with new brake pressure switches already installed. I'm thinking you will only need to replace 1 or both of the brake pressure switches to fix it this time. Look in the June '99 entry of the maintainence document I gave you and you'll see mention of the no brake light issue. Let me know how you make out. Is Tim home yet?
08-30-2006, 11:35 PM
#4
Burning Brakes
Thread Starter
HAY PAUL!!!!! yep the boy is home.....what a grin he has driving Greta, he just got home yesterday afternoon. You should be hearing from him soon, he wants to thank you for selling him such a nice car!!!! He is spending alot of time with his GF and Greta......lol
Ill check the file to see about the brake light issue, then ill check the manual for were to look.
Flyin, yep looks like it has a pressure switch...thanks
Ill check the file to see about the brake light issue, then ill check the manual for were to look.
Flyin, yep looks like it has a pressure switch...thanks
08-31-2006, 09:52 AM
#5
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The problem may not be the brake light switch.
One quick check: Use the cruise control, and see if it drops out as it should when you apply the brakes. If it does, the problem is not the brake light switch, but is more likely to be at the lamp warning box.
Just in case, here is the brake light switch info:
Up thru 1983, the brake lights are operated by twin pressure switches on the bottom of the brake master cylinder. From 1984 - up, the brake lights are operated by a simple plunger switch mounted on the brake pedal under the dash.
The earlier brake light switches do double-duty, operating both the brake lights and the brake pressure warning signal. These switches can cause some problems.
The switches are identical - one in each hydraulic circuit. They are single-pole, double-throw switches. This means that you have only one circuit (single pole) thru each switch, and that the switch chooses one of two outputs (double throw).
Each switch has three connections
ower, central warning computer, and brake light.
Not Activated
There is a power feed into each switch. When the switch is not activated (no pressure in the brake circuit) the power isn't hooked to anything.
When the switch is not activated, the central warning computer and the brake lights are connected inside the switch. Nothing happens, since there is no power applied on either circuit.
Activated
When the switch is activated by brake hydraulic pressure in one of the circuits, the central warning computer connection is broken, and the brake lights are hooked to the power feed. This removes the central warning computer from the circuit, and puts power on the brake lights.
(This might be easier to visualize if you think of three wires: one for 12 vdc, one to the brake lights and one to the warning computer. The lead that goes to the brake lights is connected to the one to the warning computer until brake pressure pushes it off of that wire and over to the one going to power.)
All three leads go to both switches.
When you apply the brakes, both switches should activate. Both switches disconnect the warning computer and connect the power to the brake lights. The brake lights come on, and no signal is sent to the warning computer, so it is happy.
If only one switch activates (either no pressure on one side of the brakes, or a bad switch), then things change.
On the switch that is not activated, the brake light circuit is still hooked to the warning computer.
On the switch that activates, the brake light circuit is hooked to 12 vdc.
The brake lights come on.
In addition, power flows on the brake light circuit back to the non-activated switch. Since in this switch the brake light circuit and warning computer are hooked together, 12 vdc is applied to the warning computer circuit. This set the Brake Pressure Warning light.
If you have a bad brake light switch, I strongly suggest that you replace both switches.
(P/N 113 945 515 G, $23.60 each plus shipping) Replacement of the switches requires bleeding the brake system, so this is a good time to flush the brake and clutch systems.
One quick check: Use the cruise control, and see if it drops out as it should when you apply the brakes. If it does, the problem is not the brake light switch, but is more likely to be at the lamp warning box.
Just in case, here is the brake light switch info:
Up thru 1983, the brake lights are operated by twin pressure switches on the bottom of the brake master cylinder. From 1984 - up, the brake lights are operated by a simple plunger switch mounted on the brake pedal under the dash.
The earlier brake light switches do double-duty, operating both the brake lights and the brake pressure warning signal. These switches can cause some problems.
The switches are identical - one in each hydraulic circuit. They are single-pole, double-throw switches. This means that you have only one circuit (single pole) thru each switch, and that the switch chooses one of two outputs (double throw).
Each switch has three connections
ower, central warning computer, and brake light.Not Activated
There is a power feed into each switch. When the switch is not activated (no pressure in the brake circuit) the power isn't hooked to anything.
When the switch is not activated, the central warning computer and the brake lights are connected inside the switch. Nothing happens, since there is no power applied on either circuit.
Activated
When the switch is activated by brake hydraulic pressure in one of the circuits, the central warning computer connection is broken, and the brake lights are hooked to the power feed. This removes the central warning computer from the circuit, and puts power on the brake lights.
(This might be easier to visualize if you think of three wires: one for 12 vdc, one to the brake lights and one to the warning computer. The lead that goes to the brake lights is connected to the one to the warning computer until brake pressure pushes it off of that wire and over to the one going to power.)
All three leads go to both switches.
When you apply the brakes, both switches should activate. Both switches disconnect the warning computer and connect the power to the brake lights. The brake lights come on, and no signal is sent to the warning computer, so it is happy.
If only one switch activates (either no pressure on one side of the brakes, or a bad switch), then things change.
On the switch that is not activated, the brake light circuit is still hooked to the warning computer.
On the switch that activates, the brake light circuit is hooked to 12 vdc.
The brake lights come on.
In addition, power flows on the brake light circuit back to the non-activated switch. Since in this switch the brake light circuit and warning computer are hooked together, 12 vdc is applied to the warning computer circuit. This set the Brake Pressure Warning light.
If you have a bad brake light switch, I strongly suggest that you replace both switches.
(P/N 113 945 515 G, $23.60 each plus shipping) Replacement of the switches requires bleeding the brake system, so this is a good time to flush the brake and clutch systems.
08-31-2006, 01:55 PM
#6
Banned
thanks for your help guys... I will be fixing this this weekend... its way sketchy driving this car without BL's, but for the next week or two its my daily driver, so I am being careful. Paul, the car is amazing. I am enjoying every second I am behind the wheel... I have made some slight changes since she was with you... I will post pictures as soon as I take my camera out on a nice day. I have only one more Q, which I will post in another thread in a minute here... till then, it is incredibly good to be home, and I will talk to ya'll and see some of you soon I am sure.