XK8 Brake light switch repair guide
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Oct 20, 2016, 06:34 AM
Senior Member
Joined: Mar 2015
Posts: 425
Likes: 119
From: Tri-Cities, (Richland), WA
I replaced the switch on mine as well, but did not want to go through the nightmare bracket replacement. I had read about this method of replacing the electronics only, and in less than 5 minutes, I had replaced my Brake Switch Electronics, start to finish.
1.) Place hand mirror on floorboard.
2.) Sitting on ground next to vehicle, reach up and bend the bracket toward the Passenger door ~1.5"s, while holding the brake pedal down to clear the Brake Pedal Lever, the bracket will bend very easily, do not push hard.
3.) Remove bottom nut with small Ratchet and Socket, clip tie wrap and disconnect harness, lift electronics over nut post on bottom of bracket and swing ~15-30 degrees to the side to clear the bracket and pull electronics off, no need to loosen the top nut.
4.) Install new electronics to old bracket in reverse, paying attention to the plastic washer at the top, and bend bracket back straight while holding brake pedal down so the lever clears the switch in the electronics, re-connect harness.
This is how I replaced my Brake Light Switch, I encountered no problems and the CC works every time, and like I said, it took 5 minutes. The mirror on the floorboard allows you to see everything that you are doing.
1.) Place hand mirror on floorboard.
2.) Sitting on ground next to vehicle, reach up and bend the bracket toward the Passenger door ~1.5"s, while holding the brake pedal down to clear the Brake Pedal Lever, the bracket will bend very easily, do not push hard.
3.) Remove bottom nut with small Ratchet and Socket, clip tie wrap and disconnect harness, lift electronics over nut post on bottom of bracket and swing ~15-30 degrees to the side to clear the bracket and pull electronics off, no need to loosen the top nut.
4.) Install new electronics to old bracket in reverse, paying attention to the plastic washer at the top, and bend bracket back straight while holding brake pedal down so the lever clears the switch in the electronics, re-connect harness.
This is how I replaced my Brake Light Switch, I encountered no problems and the CC works every time, and like I said, it took 5 minutes. The mirror on the floorboard allows you to see everything that you are doing.
Last edited by 03 XKR; Oct 20, 2016 at 09:39 AM.
Senior Member
Joined: Mar 2015
Posts: 425
Likes: 119
From: Tri-Cities, (Richland), WA
I replaced the switch on mine as well, but did not want to go through the nightmare bracket replacement. I had read about this method of replacing the electronics only, and in less than 5 minutes, I had replaced my Brake Switch Electronics, start to finish.
1.) Place hand mirror on floorboard.
2.) Sitting on ground next to vehicle, reach up and bend the bracket toward the Passenger door ~1.5"s, while holding the brake pedal down to clear the Brake Pedal Lever, the bracket will bend very easily, do not push hard.
3.) Remove bottom nut with small Ratchet and Socket, clip tie wrap and disconnect harness, lift electronics over nut post on bottom of bracket and swing ~15-30 degrees to the side to clear the bracket and pull electronics off, no need to loosen the top nut.
4.) Install new electronics to old bracket in reverse, paying attention to the plastic washer at the top, and bend bracket back straight while holding brake pedal down so the lever clears the switch in the electronics, re-connect harness.
This is how I replaced my Brake Light Switch, I encountered no problems and the CC works every time, and like I said, it took 5 minutes. The mirror on the floorboard allows you to see everything that you are doing.
1.) Place hand mirror on floorboard.
2.) Sitting on ground next to vehicle, reach up and bend the bracket toward the Passenger door ~1.5"s, while holding the brake pedal down to clear the Brake Pedal Lever, the bracket will bend very easily, do not push hard.
3.) Remove bottom nut with small Ratchet and Socket, clip tie wrap and disconnect harness, lift electronics over nut post on bottom of bracket and swing ~15-30 degrees to the side to clear the bracket and pull electronics off, no need to loosen the top nut.
4.) Install new electronics to old bracket in reverse, paying attention to the plastic washer at the top, and bend bracket back straight while holding brake pedal down so the lever clears the switch in the electronics, re-connect harness.
This is how I replaced my Brake Light Switch, I encountered no problems and the CC works every time, and like I said, it took 5 minutes. The mirror on the floorboard allows you to see everything that you are doing.
Last edited by 03 XKR; Oct 20, 2016 at 09:39 AM.
Senior Member
Joined: Mar 2015
Posts: 425
Likes: 119
From: Tri-Cities, (Richland), WA
BTW should anyone be interested, I have the 'old electronics' re-mounted to the 'new' bracket after I removed it from the vehicle. I cannot tell that anything is wrong with it by visual inspection. Holding the switch to my ear and slowly pushing the white lever in by hand I can hear the micro-switches making 'music box' like 'tinking' noises both up and down.
The white lever has a section on it that 'ratchets' further down when the switch is fully depressed, and when released the section that ratcheted down further does not re-extend. I do not know if that is the problem with the old switch or not.
However, should anyone want the Brake Light Switch Assembly 'LJB6420BB' from a 2003 XKR with Adaptive Cruise Control to experiment on, or repair and use, PM me your address and I will send it on.
The white lever has a section on it that 'ratchets' further down when the switch is fully depressed, and when released the section that ratcheted down further does not re-extend. I do not know if that is the problem with the old switch or not.
However, should anyone want the Brake Light Switch Assembly 'LJB6420BB' from a 2003 XKR with Adaptive Cruise Control to experiment on, or repair and use, PM me your address and I will send it on.
Senior Member
Joined: Mar 2015
Posts: 425
Likes: 119
From: Tri-Cities, (Richland), WA
BTW should anyone be interested, I have the 'old electronics' re-mounted to the 'new' bracket after I removed it from the vehicle. I cannot tell that anything is wrong with it by visual inspection. Holding the switch to my ear and slowly pushing the white lever in by hand I can hear the micro-switches making 'music box' like 'tinking' noises both up and down.
The white lever has a section on it that 'ratchets' further down when the switch is fully depressed, and when released the section that ratcheted down further does not re-extend. I do not know if that is the problem with the old switch or not.
However, should anyone want the Brake Light Switch Assembly 'LJB6420BB' from a 2003 XKR with Adaptive Cruise Control to experiment on, or repair and use, PM me your address and I will send it on.
The white lever has a section on it that 'ratchets' further down when the switch is fully depressed, and when released the section that ratcheted down further does not re-extend. I do not know if that is the problem with the old switch or not.
However, should anyone want the Brake Light Switch Assembly 'LJB6420BB' from a 2003 XKR with Adaptive Cruise Control to experiment on, or repair and use, PM me your address and I will send it on.
Old Electronics & New Bracket have been sent on to an interested forum member.
Junior Member
Joined: Dec 2014
Posts: 10
Likes: 0
From: new jersey
brake light switch
02 xk8 coupe
Please. What were symptoms that led to this repair?
My dash has the dual msg "cruise not available" & "check rear lights".
The light in the rear window does not light with the others, and not when the brake pedal is depressed.
Appreciate any help.
Please. What were symptoms that led to this repair?
My dash has the dual msg "cruise not available" & "check rear lights".
The light in the rear window does not light with the others, and not when the brake pedal is depressed.
Appreciate any help.
Senior Member
Joined: Mar 2015
Posts: 425
Likes: 119
From: Tri-Cities, (Richland), WA
Check that all of your Brake Lights are functioning normally. Check the 'Parking Lights' are all on, the Turn Signals are flashing, the Reverse Lamps, Rear Fog Lamps, and the License Plate Lamp all illuminate when they are supposed to. It would appear from your description that the warning is due to your Third Brake Light not illuminating, but I do not believe that does not rule out a faulty Brake Light Switch.
Junior Member
Joined: Dec 2014
Posts: 10
Likes: 0
From: new jersey
Thanks. After my message, I did some further reading and learned that the ignition must be on for the third brake light to work. It's ok, and all of the others you mentioned seem to test ok for both lighting, backup, and brakes.
That seems to leave a faulty brake switch as the culprit.
Thanks for your input
That seems to leave a faulty brake switch as the culprit.
Thanks for your input
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Senior Member
Joined: Mar 2015
Posts: 425
Likes: 119
From: Tri-Cities, (Richland), WA
Yes and no, I removed the new Green Electronics Pack from the new Brake Light Switch's bracket, then removed the Original damaged Electronics Pack from the Original Brake Light Switch's Bracket, while it was still attached to the car, and swapped the 'new' electronics with the 'old' electronics instead of trying to 'fish' the new assembly into the bulkhead.
Last edited by 03 XKR; Oct 25, 2016 at 11:23 PM.
Member
Joined: Mar 2017
Posts: 32
Likes: 5
From: Whitby, New Zealand
Good writeup from Flakster. Got my first sign that all is not well with my brakeswitch. It's only occurred once so will be ordering new microswitches shortly.
For those who intending to replace the original microswitches on the printed circuit board using Omron D2HW-A211D sub-miniature micro-switch for which was my initial thoughts. I've been informed by RS components that Omron no longer supply this part. Ie discontinued was the word they used.
So thanks Flakster for the alternative method.
For those who intending to replace the original microswitches on the printed circuit board using Omron D2HW-A211D sub-miniature micro-switch for which was my initial thoughts. I've been informed by RS components that Omron no longer supply this part. Ie discontinued was the word they used.
So thanks Flakster for the alternative method.
Member
Joined: Mar 2018
Posts: 98
Likes: 52
From: Lake Havasu City
I replaced the switch on mine as well, but did not want to go through the nightmare bracket replacement. I had read about this method of replacing the electronics only, and in less than 5 minutes, I had replaced my Brake Switch Electronics, start to finish.
1.) Place hand mirror on floorboard.
2.) Sitting on ground next to vehicle, reach up and bend the bracket toward the Passenger door ~1.5"s, while holding the brake pedal down to clear the Brake Pedal Lever, the bracket will bend very easily, do not push hard.
3.) Remove bottom nut with small Ratchet and Socket, clip tie wrap and disconnect harness, lift electronics over nut post on bottom of bracket and swing ~15-30 degrees to the side to clear the bracket and pull electronics off, no need to loosen the top nut.
4.) Install new electronics to old bracket in reverse, paying attention to the plastic washer at the top, and bend bracket back straight while holding brake pedal down so the lever clears the switch in the electronics, re-connect harness.
This is how I replaced my Brake Light Switch, I encountered no problems and the CC works every time, and like I said, it took 5 minutes. The mirror on the floorboard allows you to see everything that you are doing.
1.) Place hand mirror on floorboard.
2.) Sitting on ground next to vehicle, reach up and bend the bracket toward the Passenger door ~1.5"s, while holding the brake pedal down to clear the Brake Pedal Lever, the bracket will bend very easily, do not push hard.
3.) Remove bottom nut with small Ratchet and Socket, clip tie wrap and disconnect harness, lift electronics over nut post on bottom of bracket and swing ~15-30 degrees to the side to clear the bracket and pull electronics off, no need to loosen the top nut.
4.) Install new electronics to old bracket in reverse, paying attention to the plastic washer at the top, and bend bracket back straight while holding brake pedal down so the lever clears the switch in the electronics, re-connect harness.
This is how I replaced my Brake Light Switch, I encountered no problems and the CC works every time, and like I said, it took 5 minutes. The mirror on the floorboard allows you to see everything that you are doing.
And, after filling my contortionist quota for the month..I got to enjoy my newly working cruise control.
THANK YOU 03 XKR and Flakster! I don't think I would have even attempted it without your excellent information
Junior Member
Joined: Jul 2018
Posts: 13
Likes: 4
From: 94546
Hi,
Does anyone know how to test the Brake Light Switch to confirm whether it is defective or not?
The reason for question is I bought a brand new OEM Brake Light Switch from Amazon. Installed it (following the great tips from folks who has done it) but the dual msg "cruise not available" & "check rear lights" return.
I wonder if I got a defective unit or not.
Appreciate your knowledge sharing =)
Thanks
Gordon
Does anyone know how to test the Brake Light Switch to confirm whether it is defective or not?
The reason for question is I bought a brand new OEM Brake Light Switch from Amazon. Installed it (following the great tips from folks who has done it) but the dual msg "cruise not available" & "check rear lights" return.
I wonder if I got a defective unit or not.
Appreciate your knowledge sharing =)
Thanks
Gordon
Junior Member
Joined: Jul 2018
Posts: 13
Likes: 4
From: 94546
Thanks RJ237
I was able to verify the brake light switch is indeed NOT defective, that is the 2 outer pins are normally in closed circuit (resistance is near zero); the 2 inner pins are normally in open circuit (no resistance)
Now I am really struggling what is going wrong here. I have checked all the rear light bulbs and connections. They all seem OK.
I also noticed that the dual msg usually will show up soon after I applied the brake a few times regardless of how far or how fast you travel.
If I stop and re-start the engine, the dual msg will clear until the next cycle.
It is intermittent but very predictable.
Does anyone has similar experience and how you go about to fix it? Thanks for sharing
I was able to verify the brake light switch is indeed NOT defective, that is the 2 outer pins are normally in closed circuit (resistance is near zero); the 2 inner pins are normally in open circuit (no resistance)
Now I am really struggling what is going wrong here. I have checked all the rear light bulbs and connections. They all seem OK.
I also noticed that the dual msg usually will show up soon after I applied the brake a few times regardless of how far or how fast you travel.
If I stop and re-start the engine, the dual msg will clear until the next cycle.
It is intermittent but very predictable.
Does anyone has similar experience and how you go about to fix it? Thanks for sharing
Junior Member
Joined: Jul 2018
Posts: 13
Likes: 4
From: 94546
Hi RJ237, I noticed there are several other posts talking about this issue, hence I added my comment/observations in those threads hoping to get more feedback.
In my case, I have tested the switch works properly. The continuity of the 2 microswitches is fine. The msg does not occur immediately when you depress the pedal. In fact, I have depressed the brake pedal multiple times and the msg won't show up. So it is intermittent in that respect. However, the msg is predictable that it will show up at some time after you depressed the brake pedal. In my observation, the msg usually will show up within 5 mins after driving and applying the brakes a few times.
I am going to try re-solder the Brake Light Switch wire leads (as Daro31 suggested) in another thread and see that would take care it. I can't think of anything else..
In my case, I have tested the switch works properly. The continuity of the 2 microswitches is fine. The msg does not occur immediately when you depress the pedal. In fact, I have depressed the brake pedal multiple times and the msg won't show up. So it is intermittent in that respect. However, the msg is predictable that it will show up at some time after you depressed the brake pedal. In my observation, the msg usually will show up within 5 mins after driving and applying the brakes a few times.
I am going to try re-solder the Brake Light Switch wire leads (as Daro31 suggested) in another thread and see that would take care it. I can't think of anything else..
Junior Member
Joined: Jul 2018
Posts: 13
Likes: 4
From: 94546
Veteran Member
Joined: Dec 2010
Posts: 8,835
Likes: 2,924
From: Douglasville Ga.
Hi RJ237, I noticed there are several other posts talking about this issue, hence I added my comment/observations in those threads hoping to get more feedback.
In my case, I have tested the switch works properly. The continuity of the 2 microswitches is fine. The msg does not occur immediately when you depress the pedal. In fact, I have depressed the brake pedal multiple times and the msg won't show up. So it is intermittent in that respect. However, the msg is predictable that it will show up at some time after you depressed the brake pedal. In my observation, the msg usually will show up within 5 mins after driving and applying the brakes a few times.
I am going to try re-solder the Brake Light Switch wire leads (as Daro31 suggested) in another thread and see that would take care it. I can't think of anything else..
In my case, I have tested the switch works properly. The continuity of the 2 microswitches is fine. The msg does not occur immediately when you depress the pedal. In fact, I have depressed the brake pedal multiple times and the msg won't show up. So it is intermittent in that respect. However, the msg is predictable that it will show up at some time after you depressed the brake pedal. In my observation, the msg usually will show up within 5 mins after driving and applying the brakes a few times.
I am going to try re-solder the Brake Light Switch wire leads (as Daro31 suggested) in another thread and see that would take care it. I can't think of anything else..
Junior Member
Joined: Jul 2018
Posts: 13
Likes: 4
From: 94546
Hi RJ237, not at all. I am all for any tips/suggestions you or anyone could offer.
No, I did not check continuity of both circuits with the pedal depressed.
I was checking the circuits with the brake light switch removed from the car. Confirmed continuity OK, and installed it back.
Now that you have mentioned, I will recheck continuity of the 2 circuits with the pedal depressed. Thanks
No, I did not check continuity of both circuits with the pedal depressed.
I was checking the circuits with the brake light switch removed from the car. Confirmed continuity OK, and installed it back.
Now that you have mentioned, I will recheck continuity of the 2 circuits with the pedal depressed. Thanks