Has anyone here found a way or know how to disable the need to pull up the handbrake every time l want to open or close the top ?
I know l could short the switch but l would like to keep the warning light.
Also l've seen a mod. for the XK8 top to allow closing of the top remotely. Anyone fitted that to the XJS ?

 

If you cut the splice wire that goes from the parking brake switch to the convertible top ECU and ground it, the top will work with the handbrake off, and the park brake light on the dash will still operate.

You can also use something like this.......

Remote Anything

It has 4 outputs....... 2 are latched, meaning you press the button once and the signal stays on. the other 2 are pulsed, meaning the signal is only there while you hold the button in.

You can use the 2 pulsed outputs to pull the control wires from the top ECU to ground. This is basically what happens when you press the switch in the center console, ie it pulls one of 2 wires to ground, which tells the top ECU to either open or close the roof.

I was going to do this on my car as I have a remote anything installed anyway. The issue I had that stopped me from doing it was the fact that you can't remotely open the top if you haven't manually unlatched it first. You could close it remotely (if it was raining for example) but again, the top wouldn't close tight because you need to manually latch it once it's powered up. The XK system automatically unlatches the top from the windscreen rail so you really do have remote open and close. One of the members of the bay area Jaguar group has this mod (From the JagWrangler) and it is really neat. Just a pity it can't be fully enabled on the XJS because of the manuall latching

 

I would really like some more information on this. Where is the best place to make this cut and ground it? I have the schematic but don't really know what I am looking at and can't find the wire.

 

Whats wrong with pulling the lever just enough to trip the switch, but not enough to actually put the park brake pads against the rotors? It only takes a slight pull to do that. Leave it that way if you want?

 

The reason I am wanting to change it is that the connection to the brake is unreliable. The brake always sets and the dash light always comes on, but the power doesn't always get to the top's motor. I think the switch on the brake is bad and it seems like bypassing the whole thing makes the most sense as I don't want to deal with the brake anyway.

 

The switch you are speaking of is very accessible if you move the seat all the way forward. its just one of those little micro switches, and may be dirty, broken, or both.

 

Thanks, I've already had it open, looked at it, and I believe its broken. This is an opportunity to fix something better than new, I don't want to use the parking brake again. I know it can be bypassed by grounding a certain wire per the thread, I just need to know which wire.