XK8 roof fails to open

[bharrt]

need help, the roof fails to open on XK8, year 98.
when the roof switch is pressed, the rear windowns go down as normal,with the front, but the roof latch fails to realise. any ideas why this happens?
also i have just found the auto headlight fails to work. i have checked the sensor and its clean, and set correctly,
i have owned the car for 6 years and its been good as gold.

[motorwise]

start with the obvious - check the system fuses - after that it could be a relay or control unit, you'll need proffesional help with this if it's not a fuse

[Trooper2]

Here are the possible causes for top won't unlatch:






As far as the auto headlights not working, are the mirrors dimming?

If the mirrors aren't dimming then I would look at the ground wire that comes out of the mirror connector. The mirror gets it's power from the Body Processing module but we already know that module is working because you've said the rear quarter windows are dropping.

P.S. welcome to PistonHeads.

Edited by Trooper2 on Thursday 4th January 02:48

Edited by Trooper2 on Thursday 4th January 02:50

[bharrt]

i have checked all the fuse and they are ok, and all relays are pushed home, battery is, ok, and the vehicle is parked when i try the hood switch?

[Trooper2]

Use known "good" relays in place of the relays for the convertible top for testing purposes, headlight relay, Etc, as long as it is the same type, size and shape and remember or mark where you got them from.

The micro-switches on the latch are known to fail, but at that point I think you need to consider visiting a Jaguar service department.

You have stated that your auto headlights aren't working, is there any hydraulic fluid dripping out of the rear view mirror? when the convertible top hydraulic lines fail at the windscreen header it is common for the mirror to start to fill with fluid and this could cause both of your complaints. If this is the case then definitely go visit a Jaguar service department.

Edited by Trooper2 on Thursday 4th January 12:45

[bharrt]

just update,
checked all relays and they are switching over correctly,
when the switch is pressed pump starts but the latch fails to open.
have checked for leaks and none are present. Tried to realse the latch with the allen key after placing the pump in manuel mode, and the latch is solid, car is booked in for service next week so will ask dealer, probley cost loads...

[Trooper2]

Sorry it's not a DIY job and hope it isn't overly expensive to fix. Sounds like the actual latch has siezed, but I'm interested in the final diag.
so I will check back.

[melhook]

I know I'm stating the obivous, but no one has mentioned the fluid level, some of these suffered from the pipes that feed the latch leaking down the N/S A post.

[Trooper2]

I hinted at leaks...

[jamesc68]

Had the same problem. Ended up a siezed latch which could not be released. Required a new release mech ( i think the latch is part of an assembly which Jaguar will not supply seperated). Unfortunately it was quite expensive to fix. Sorry, hope this is not the problem for you.

James

[bharrt]

car has been with the dealer all day today, for 90,000mls service, MOT, and roof fault,
so far they have informed me i need front disk and pads,
roof fault is fixed if they flush the hyro- fluid
just wait for the big bill
pick up on Tuesday.

[bharrt]

just picked the car up, and all works now
total cost £1666.59
thats for service, MoT, front disks and pads, and roof fluid flush. front wheel alignment.

[Trooper2]

bharrt said:

just picked the car up, and all works now
total cost £1666.59
thats for service, MoT, front disks and pads, and roof fluid flush. front wheel alignment.

bharrt, did they say that the convertible hydraulic fluid had congealed?

[bharrt]

yes they did and they still asked me to pay for it