Hello Friends,

(This post has been edited because I figured out half of the problem with the dash connectors. Hopefully my solution will save someone else some time.)

I pulled the dashboard from my 1997 XK8 Coupe (I think 1997 is a key to my question) and had a heck of a time removing the dashboard electrical connectors. I watched the video referenced in the sticky and actually, have removed them before. But second time wasn't the charm.

However, I figured it out. Later models, it seems have some sort of lever that rotates. On my 1997, I simply squeezed the top and bottom levers and pulled. The connectors popped right off. I have no idea why it took me so long to figure out. Hope this helps someone else, though it's hard to believe anyone else would make such a simple mistake.

And here is where I need some help in making a wild guess. I'm pulling the panel to access the wire harness behind the panel. Every wire on this car (not virtually every wire. Every wire) in the dash has been spliced. I've located bad splices that kept the car from running and more recently, the turn signals. But the brake lights are out and I can't find the bad splice to hook them up again, if a bad splice is indeed the problem. I believe they were bodged the first time around with a wire from the brake switch and some other very bad ideas. I'd like to do it right this time. Where might one splice or cut the (Blue Grey ?) brake light wire that leads from the front to the back of the car, if one were of a mind to do so?

Thank you in advance for your help.

 

Not 100% sure what you're hoping to do, but that Blue Grey wire goes from the brake switch to the relay in the boot (trunk) via :
BT1, RH12, FCS, AC13, ACS, & AC26.

RH12 (pin 1) looks easy to get at - rear of centre console. Otherwise, relay in trunk ??

 

There is a red wire that someone, at some point, spliced in to operate the brake lights.

I would like to discard the red wire and restore the wiring/electrical system to the state at which Jaguar originally intended.

Anyway, I can't find the end of the blue grey wire and other issues in my exploration are baffling.

Leaving the brake switch, I find black (might be purple)/green, green, black and red/yellow wires in the pigtail connector. I believe the red/yellow was where the original red wire splice started. However, I don't see a red/yellow in the Jaguar schematic. These colors change after the connector.

At this point I will probably just buy a new brake switch and see if that doesn't re-activate the system. The reason I haven't done so already is because I recently replaced the missing lamp control module (it had been supplanted with a gaggle of wires and solder) and in doing so a received lights out warning on the dashboard. After repairing a missing turn signal (by fixing a splice), I still see no warning for missing brake lights, or any warnings.

So, not sure if the brake switch was bad, what I was trying to do, was figure out where to re-attach the blue/grey wire if it were spliced.

However, my theory now is that the brake switch is kaput and the red wire was attached to the brake cancel side of the switch.

If David or anyone has other thoughts on the matter, I would love to hear. Otherwise, it's a new brake switch for me (and all the wriggling under the dashboard that I have been trying to avoid !)

 

According to the wiring diagram - there should be four wires connected to the brake switch :
Black, Green/Black, Green/Purple, White/Blue

at the pigtail connector - Green/Purple & White Blue (cruise control cancel) stay the same and Black becomes White/Orange and Green/Black becomes Blue/Grey.

No sign of anything red or yellow on the wiring diagram.

Does that help at all ?

 

It tells me to pull the brake switch because something isn't right!

 

Thank you for your help David. I pulled the switch and found one microswitch is on and one is off, as it should be. But judging from the schematic, it seems the wires/switches aren't lined up correctly. I can't be sure. It's dark. It's late. And I'm not sure I'm seeing the colors clearly. But I'm not surprised. I suspect this isn't a problem others are likely to see, but will report back when it's fixed. Just to shout Victory ! (assuming I will be shouting Victory !).

Thanks again.

 

No victory as of yet (for brake lights). Brake switches seem to operate properly. The center wires (black/green-black) show an open switch when the brake is depressed and the opposite is true for the outer wires. Replaced the BPM and no joy. Ran a wire from the blue grey side of the brake switch to the fuse box / relay in trunk. That is, power is 12 v when the brake is not depressed, but is 0 when depressed. Still no lights. I believe swapping the jumper wire to the other side of the brake switch should either activate the relay or allow me to operate the brake lights directly (because 12v on a switch).

(EDIT: The brake switch is out...perhaps the brake switch is always in the depressed position, but closes the circuit when you press on it?
...anyway, I made another discovery...There are 12 v going through the switch when the ignition is off, but it shuts off when you turn on the ignition...So, switched power is an issue...I believe there is a red and white wire that plays a part in this...Any thoughts on switched power are appreciated.)

But there is still the problem of the Park solenoid, which doesn't activate (and from the notes I have, hasn't worked since 2009.) Reading no voltage to the solenoid. Before swapping the BPM (and about a dozen other things) I had constant 8v, but no activation. The out of park microswitch has a broken tang, but works. I activated that manually, but still no life in the solenoid. I'll run 12v to it to see if it works (could slap head if it's broken) but that doesn't explain the lack of switched voltage when I step on the brake.



Frustration level reaching overload levels.

Thank you for listening and I hope the solution is out there.

 

Is it a white wire with a red tracer line, or a red wire with a white tracer line ?
There's quite a few of both in the wiring schematic, but we might be able to narrow things down a bit.

 

Well, I've had victory of a sort, with the brake lights if not the transmission interlock.

In messing around with the wires in the trunk, I discovered that all three brake lights (including the CHMSL) will light when the blue gray wire leaving the fuse box (but connected to nothing up front) is sectioned and grounded. This implies that 12V (B+) is provided at the back of the car and the brake switch completes the circuit by completing a ground. This may seem obvious, but it was news to me as I was under the impression 12v/B+ traveled to the rear. For those with similar problems, cutting and grounding the blue grey wire will eliminate the possibility of brake light issues caused by faulty modules/relays/fuses etc. in the trunk or reveal such problems.

I also know - or assume - my BPM is good, since it's been replaced.

Also, the ignition switch is good because the white/orange wire leading to that switch completed a ground when I bypassed the wiring between the brake switch and the ignition switch.

So, I could button the car up as is, but the gearshift interlock still doesn't operate. Also the radio doesn't work.

I'm getting 8v to the interlock, unswitched by the brake switch. My guess is that somewhere a ground wire is shorting on a 12v wire, but I haven't found the short.

Finally, the radio is seeing 12v, but I haven't determined if it has the same problem (lack of switched or digitally switched ground) or if it's just busted.

The car suffered from a leaky (porous) windshield which apparently precipitated (cough, cough) its many problems.

Again, David, I appreciate you following my tail of woe. If you, or anyone else, have any suggestions, please put them forth.

Thank you for reading.

 

Sounds like progress !!

A quick check for the radio would be whether you have 12v + on both fuse #9 (10A) and fuse #12 (5A) in the passenger side fuse box in the engine compartment. The first is always live (to keep memory for station selection etc) and the other is ignition switched and also sends power to the antenna and (if you have the premium kit) the power amplifier in the trunk. At the head unit - brown/purple is 12v+ battery, and White/Yellow is 12v ignition.

 

To wrap up this thread:

Re Radio: All three B+ inputs are delivering. Radio is completely dead as is the antenna. No power going to the amplifier in back, at least before I found two small connectors, unattached in back. I plugged one into the antenna. Can't see a matching connector for the other.

Where might the connector be? Ideas?


Also, the console - which includes wiring for an old telephone is not hooked up.
Perhaps the radio will light when the console is attached?
Or am I missing a power connector to the amplifier, somewhere at the rear of the car?

Plan is to bolt everything back in place and if it works, great. If not, I can still drive without a radio for a week or three.

Re Brake Lights: They work, but the brake switch is wired directly to the fuse box in back. Pressing the brake grounds the circuit and activates the relay as per normal. Don't know about cruise control.
The shift solenoid works, so I will just jump a wire and fuse over from the brake wire that runs front to back. I've spent more than enough time trying to find the short and everything works, so I'm buttoning the car (and its many open panels under the dash) back up.

Interestingly there was a long post/thread regarding the gearshift solenoid back in 2011, where the writer also was seeing 8v at the solenoid, with no action. After a lot of effort, he finally abandoned the effort, though he didn't jump the wires.

Thank you David for all of your help. And for others who tuned in.

Hopefully the next thread I launch will have something to do with actually driving the car (which my wife has named the "Devil" ! Hrrumph...I prefer "Sweat Equity")

 

I changed microswitches to brake switch to fix interlock and totally non-working brakelights. Issue came after longer period of car not used. So original harnes broken somewhere by itself?!?

No avaid from switch but here's what fixed issue: There was no connection from AC13-2 to brake switch Black.

Rewired Brake switch Black (B) -> AC26-4 White-Orange (WO)
-from Brake switch Connector AC26-4
with White-Yellow wire
-to Right Footwell - Fascia Bottom Connector AC13-2

Anyhow all the brake lights working and interlock too.

Br,

T