Brake Light Switch
 

Hello,

Saturday, I started getting "Check Rear Lights/Cruise Control Not Available" errors.

I am thinking the Brake Light Switch went bad.

On the XKR, is replacing the switch the same as in the XK8?

I have a link here posted by Gus on 1/1/12.
JagRepair.com - Jaguar Repair Information Resource

Thanks,

I would guess that the procedure is exactly the same. Hopefully some R owners will chime in and confirm....

Sure is, exactly the same.

I had the same problem with the brake light and went to the junk yard. Found an old jag with the same type of switch, but the pigtail was a little shorter. Just did a little solder job and exchanged the pigtails. Cost $5 instead of the $197 at the dealers. Also found that the problem was one of the two little micro switches inside the switch. This would also be a very easy fix with a solder gun. Hope this helps.

Thank you. I will get on this right after I change out the front struts and fix the A/C. I appreciate the replies.

Thanks!

Zero Dollar Fix
 

FWIW, I went in the other direction. I removed the switch from the car, and took a hard look. There was no obvious sign of bad solder on the pigtail, or anything wrong with the switches themselves. The issue was that the plastic cam that was activated by the brake pedal was worn unevenly and caused the switches to click separately. My understanding is that these switches are supposed to be opposite of one another (one closed, the other one open) at all times, and are built to that effect (one is NO, the other one is NC). When the cam causes one switch to click early in the travel, both switches are in effect at the same state, the computer detects it and throws the error. For now, I ended up propping up the "low" side of the cam with a thin strip of electrical tape, all the while making sure the switches were clicking together. It has been over a week since the repair and the issue has not come back (daily driver), so I am pretty confident in the diagnostic. As to the repair, I am pretty sure the issue will come back once the tape slips, wears out or otherwise stops serving its function. For a more permanent repair, maybe a few layers of glue would do, or alternatively, maybe shaving the "high" side would be easier. Best of luck, keep us posted.

One last question on this. Can you do it without removing the seat?

Yes, if you are less than five feet tall, an experienced circus contortionist, and have the hands of a five-year-old Chinese girl....


Pull the seat. The job will be significantly more comfortable and you may not exhaust your full vocabulary of curse words....

Thanks :).

I left the seat in place, and it is not entirely comfortable. Altogether, I would say it is more frustrating than difficult. I am about average build.

One more thing. You can remove the bracket with the switch on it by removing the 2 nuts next to the brake booster, or you can remove the switch off the bracket, and leave the bracket in place. If you take the latter approach, only the bottom nut needs to be removed. No need to mess with the top nut as it puts no pressure on the switch itself.

Note to self: Take more pictures!

Thanks.

I'm thinking, my son is 11, 12 in June. I have taught him a few things, he replaced the battery in my wife's Lexus with supervision, and helped me with the brake job. On the battery, he did everything except lifting the battery in place.

Maybe I can get a look at it, un-bolt from engine bay and send him under there to put in the new one.

That is indeed your best shot. Let your son do the install work from the floor of the cabin while you guide the two bolt posts through their holes from underneath the hood. This job goes so much easier when you have two people doing it. When we replaced the brake pedal switch assembly on my wife's XK8 in October 2012, she was on her back in the floorboard pushing the new switch up into the firewall while I was underneath the hood pulling the switch's bolt posts through their respective holes via the monofilament fishing line I had tied to them to make the entire process easier for both of us....

I hope she charged you the daily rate Jon / and no discounts for child labor they work just as hard ! Good luck!

Nice :)

Hey, it's her freakin' car, not mine. She'd better help if she knows what's good for her (and no whining about it, either)....

I bought my '99 xk8 back in '09 with 36k and the switch was my first necessary repair. found a good indy shop in town that works on Jags and they took the car in at 8am and said I could pick it up at around 1-2pm.


They didn't get it done until the next day, late in the afternoon. I forgot to ask em if they took the seat out but because of the lengthy amount of time to actually complete the r&r, i'm assuming they didn't.


they billed me $90 and I was relieved!

For $90 I'd get mine fixed tomorrow! I am currently living with no cruise control (I do have brake lights) because I just can't bear the thought of lying on my back, poking around under the dash. Unless he's done it before, I don't imagine any mechanic would realize what he's getting into by accepting the job. The bill could be a shocker.
I recently took my XK8 to a Connecticut repair shop for emissions testing and before I said anything, the mechanic got a sort of panicky look on his face and almost yelled at me, "We don't work on Jags." He was relieved when I explained I was just there for emissions.

brake switch
 

try wd40 first I managed to get the red tube into the switch were the brake pedal touches and gave it a good blast from a new can it didn't work straight away but after a 15 min journey restarted engine warning light went out its been okay for the last few days

"Flashing" the brake light switch
 

Somewhere someone posted that he powered a standard automotive bulb through the cruise part of the brake light switch and cured his "chk rear lts/cruise N/A" error message. I tried it and sure enough, it cured the problem. Many thanks to that guy! Measure the resistance of the cruise part of the switch - should be about 0 ohms with pedal up, infinite with pedal pressed. Mine (and this other fellow's) read anywhere from 5 ohms to hundreds or k-ohms or even open with the pedal up. So I pulled a fuse, found a source of key-off battery voltage, connected to one side of the bulb, connected the other side of the bulb to one of the switch leads, connected other switch lead to ground (amazingly difficult to find a good ground - ended up loosening a fender bolt, putting the wire under it and and tightening it back down). Bulb lights. Push pedal, bulb goes out; release pedal, bulb lights. Repeated a few times. What this does is put a couple of amps through contacts that normally only handle a few milliamps (the contacts are rated for three amps, so no strain). The relatively high current burns the oxide off the contacts and restores them to good working order. Biggest problem is connecting to the thin male pins on the switch connector. Since the cabin air temp sensor uses the same connector type, I cut it out and used the female part to connect to the BL switch. Re-installed the cabin air sensor connector with quick disconnects - next time it will be easy! Sorry for the long post - hard to explain in a few words.

Fmertz:
I am currently at the same place and mindset as you when you made this post in 2015. My question is: Are you still pretty confident in your diagnosis?
I slightly twisted the microswitch lever which in effect did the same as adding tape. I used a stethoscope to hear each switch click. I just did this before seeing your post and I have not yet proven it over time.
Many thanks