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no brake lights 82 928

 
Old 06-02-2011, 12:01 AM
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camc61
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Default no brake lights 82 928

i have no brake lights on my car.there is a brake light warning on dash.i checked power to brake light switches there is voltage at both switches.i tried appling 12v directly to both wires on switches still no brake lights.anyone have an idea.thanks
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Old 06-02-2011, 12:07 AM
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Dean_Fuller
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Brake switch under the master cylinder at the booster. VW has a part for cheap. There are 2 but sometimes replacing 1 will fix the issue.
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Old 06-02-2011, 12:19 AM
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jpitman2
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Unlikely that both switches have failed at once, but IIRC my brake lights will come on with only the front switch connected. What warning msg are you seeing - Brk Press, or something else? This warning indicates one switch is firing but the other is not - circuit imbalance - cleared only by disconnecting battery briefly. Fuses and bulbs OK?
jp 83 Euro S AT 53k.
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Old 06-02-2011, 10:57 AM
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WallyP

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Bad connection at bulb controller or faulty controller, or bad connection somewhere on wire to rear of car.
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Old 06-02-2011, 11:35 AM
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Have you played with the fuses lately following the owners manual? In the 82 manual it calls for an empty spot on the fuse panel. Doing this made my lights not work, put the fuse back in presto I had lights again. Funny typo had me chasing stupid things for an hour.
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Old 06-02-2011, 02:30 PM
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soontobered84
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Did you take your passenger under dash tray out for any reason? The bulb controller is attached to that.
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Old 06-03-2011, 12:51 AM
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camc61
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thanks for the replies evryone.i checked the brake sockets and where they connect at the pin connector.when i apply 12 v directly from battery both brake lites come on so no prob at rear.does anyone know what wire or wires feed to the rear pin connectors (two) at rear?also i did take the tray under pass dash out but didnt see any thing attached where is the bulb controller and what does it look like?
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Old 06-03-2011, 12:57 AM
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also my dash warn light says brake light in red
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Old 06-03-2011, 03:08 AM
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Exact wording of msg please. 'Brake light' ? or 'brake press' ?
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Old 06-05-2011, 12:50 AM
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ok i disconnected the power 12v wire to the rear stop light switch and my brake lights are now working how long will this last ? using only the one switch.i bought two switches just trying to figure out how to rplace them?I thank all you guys for your help,your advice jpitman2 payed off thanks.
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Old 06-05-2011, 06:25 AM
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No reason it shouldnt keep working, until the one connected switch fails. You will also not know if the other circuit fails, so you really should install the 2 new switches , and connect both up.
jp 83 Euro S AT 53k
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Old 06-08-2011, 11:04 PM
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yest thanks for reply,i bought two new switches now i need to get the correct tool for job looks like 22 m but very tight space.also to answer your Q eairlier the light on dash flashes in red and says brake pr. with a round little brake symbol.but brakes seem to work ok.and not squealn.
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Old 06-09-2011, 12:06 AM
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WallyP

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A frequent repeat...

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: power, 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)
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Old 06-09-2011, 10:22 PM
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Originally Posted by jpNcos View Post
Have you played with the fuses lately following the owners manual? In the 82 manual it calls for an empty spot on the fuse panel. Doing this made my lights not work, put the fuse back in presto I had lights again. Funny typo had me chasing stupid things for an hour.

Interesting...I just popped out the "extra" fuses (3 or 4 I think) from my '83 US and lost my brake lights and cruise. Thought it was the fuse, checked, changed, same problem. Gonna fill those empty spots now to see if it's fixed!

~Roy
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Old 06-09-2011, 11:28 PM
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thanks wallyp that explantion was great i now underdstand it correctly once i replace both switches the warning lite will go away.i was wondering what the third wire was for.thanks caspermj.i will check my owners manual and the fuse panel i know my cruise dosnt work also.maybe that is why.thanks again for your guys help.
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