No brake lights

[mtsipe]

Hello. I need help diagnosing my non-working brake lights. I will go through what I did so far. I wanted to install a third brake light with a product from gowesty.com ,

Vehicle Specs:
1991 Vanagon Weekender with 1.9 tdi alh conversion with rebuilt transaxle with 4.59 ring and pinion

What I have done:

1. I ran the wiring along the weather strip of rear window. Went through the wiring sleeve on the upper left side with the defroster/rear window wiper. Fed the wire through the hole with a ground connected to it. Then fed the wire down the coolant hoses. Once the wire was down near the left light assembly, I installed a ground for my third light by drilling a hole. Then I fed the other wire through the assembly sleeve and connected the positive to the Black wire with Red stripe as directed. I then did a test and no brake lights(left or right or new third). Seriously frustrating.

2. First thing I checked was the fuses, none were blown/broken.

3. I checked the bulb in a different socket and it works.

4. I tested the wire for power and there was no power. I also disconnected the third brake wiring from the assembly then tested, still no power.

5. I tested both brake light switches on the master cylinder underneath the instrument cluster. Both had continuity. I bypassed both switches with a wire in each wiring harness connector to see if the switches were bad but still no brake lights.

6. I went to the brake pedal. I tested the brake light switch and the continuity failed. I got a replacement switch that tested positive for continuity. I installed the switch and STILL NO BRAKE LIGHTS. UGH

7. I tested the brake light switch wiring harness connector and it has power coming to it.

8. I ran a testing wiring directly from the switch outside the van and back to the tail light assembly. Still no brake lights.

9. I connected the test wire directly to the third brake light. The third brake light lit up!

10. I then tried to connected the two wires to the brake light harness and the brakes would not light up and the third brake light would go out.

11. I am assuming that there is a bad ground somewhere but the wires go into a sleeve and to the front of the vehicle.

Can anyone explain where the ground could be? I have been looking through the Bentley Manual exhaustively trying to find the ground diagram.

Is there anything I am missing or forgetting to check?

I can't stand not being able to drive my van since it has no brake lights. I thought about running a wiring directly from the brake pedal as temporary fix but I want a permanent fix.

sincerely.
reburta rebubula

[mtsipe]

Is this the right diagram? And how to decipher where the ground is located?

[fxr]

Did you try the brake lights with the engine off or running? The brake light switches are pressure-sensitive switches, and it takes a bloody hard push on the pedal when the engine isn't running to make them come on. I tend to use a length of wood jammed hard between the brake pedal and the steering wheel when testing the brake circuits...
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Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300

[Ahwahnee]

[kamzcab86]

[mtsipe]

kamzcab86, Thank you for your feedback. I tested each switch individually and no luck. My ground is good. I tested the brake pedal switch for power and it had power without the motor running. I have managed to track down the location of the brake light wire(Black with red stripe) from the back of the black wiring harness in location E16. Since there is still no power, I plan on running a new wire from that location(which will be tight because of the wire cluster) directly to the tail light assembly. I am keeping my fingers crossed that this will complete the circuit.

One other thing I tried yesterday was that I took the wiring harness off the back of the tail light assembly, connected the ground and ran a test wire from the brake pedal. One at a time each fixtures' brake light lit up when depressing the brake pedal, so it's not an issue with the tail light assembly. I would like to note that I had upgraded to LED exterior lights with a bulbs and correct relay switch. The system worked great for about a 18 months up until this recent issue.

[mtsipe]

An update, I installed a temporary fix to make it through the summer without being in the shop any longer. I installed trailer lights and connected them through the brake pedal switch. They work great.

Now, I think since I have done so, I might have figured out my original problem but I need some insight on the matter. The reason being I needed to put a relay switch to reverse the brake pedal switch(before the relay, brake not depressed and the lights were on, brake depressed and lights go out).

Long before my brake lights stopped working, my wife and I would hear a clicking sound. When I installed my relay switch for my temporary fix, the noise sounded very familiar. I looked up the diagram in the Bentley Manual and there were no relay switches pertaining to the brake lights.

Does anyone have any thoughts?

[fxr]

[VikingWagen]

Turns out my van has a similar problem and I have yet to track it down. Not sure what fxr was talking about when he mentioned there is no brake pedal switch. There is on my 1990 syncro westy with cruise control and there was also one on my 1984 2wd westy. Both OEM wired brake systems.
What I've found so far with my van: Fuse #2 is good, voltage to fuse#2 is present, no voltage at brake peddle switch, no voltage at either brake light sockets or tail light connectors, continuity ok on peddle switch & brake fluid level switch, master cylinder brake switch not yet checked, associated grounds not yet checked. Also should mention that the brake lights have been intermittently malfunctioning before this total failure. Hope we both get to the bottom of this, mtsipe.

[VikingWagen]

Problem solved! Actually, there wasn't really a problem at all. One of the brake fluid switches was not reacting to pressing the brake pedal down probably due to the van sitting for a few months. Once the engine was started and the vacuum booster working, the brake lights came on. All that time diagnosing was for naught.

Sorry to jump on your thread, mtsipe. Did you find out what was causing your brake light issue?

[danfromsyr]

explorative educational frustrating
but not for naught
it all adds to awareness and becoming a master of the van
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