I probably created this problem as collateral damage to the replacement of the hydraulic lines that raise and lower the top of my car and that also operate the latch that holds it closed, but I can find no reference for it in the volumes of information about this otherwise well known problem. So I'm here asking for help.

To make a very long and painful story much shorter, after I replaced all my hydraulic lines with the very nicely prepared new set provided by Klaus of TopHydraulics, the top dutifully goes up and down just fine, with one remaining problem: when the top is all the way down, two things that are supposed to happen, don't: 1) there is no retraction of the catch above the windshield, and 2) there is no "chime" to signal completion of the cycle.

I suspect that both of these are from a single problem having to do with the failure of the "system" to sense that the top has reached the down position. I cannot figure out, however, what the point of failure is. Could it be a sensor (wherever that is)? Could it be a relay (whichever one that is)? Could it just be gremlins?

This beautiful car reminds me why it's my first British car since my very first car back in 1965: a 1959 Triumph TR-3. Things are hard to get to and require an inordinate amount of disassembly to repair. It reminds me of a joke: Do you know why the British don't build computers? Answer: They can't find a way to make them leak oil.

Anyway, if anyone can help me out with a suggestion for where to look next, I'd appreciate it.

Best regards,
Mike

 

Mike,

There is indeed a sensor which, if it isn't sensing, would explain exactly what you're seeing. It's on the right-side ram and should create a switch closure when the top is fully lowered.

Not unusual for its connector to be disturbed in the course of changing hoses.

(I'm assuming the latch behaves normally when you raise the top, so that we can rule out hoses being on there backwards.)

Good luck.

 

Dennis,

Thanks for the reply! We apparently have twin cars.

I'm assuming the sensor is that fat buttom-shaped object at the top of the lifting cylinder, with a single (black/yellow) wire coming out that joins its mate from the bottom before diving into a shared tube by way of which it proceeds to the fist connector I see, which is a four-wire block under the back seat. The sensor itself seems pretty firmly attached to the cylinder, but I'm guessing it will come off if I really pull hard enough?

Can I replace just the sensor? Is it possible that the relay got burned up? How would I tell which relay belongs to this device? I can think of more questions, but this is probably enough for now.

Thanks a bunch!

Mike

 

How may test cycles have you run?

It sometimes can take quite a few for all of the air to be expelled from the hydraulics and for normal operation to resume after a hose replacement.

BTW the cylinder sensors are internal to the cylinders...do not try to remove them.

 

I've run the top up and down maybe ten times, but I'm going to go right now and cycle it mercilessly. We'll see what happens.

Thanks for the tip about the location of the sensors!

Mike

 

Also check the fluid level remains between the embossed lines on the tank as the air is expelled.

 

I am making a joyful noise here, as on the second reiteration of running the top up again, I heard that reassuring click of the latch closing and the chime going off. In other words, problem solved!

Without this forum, I'd probably have to sell this car. I love it dearly, but must confess that all the automation in new cars leaves me (a retired computer systems administrator) longing for the days when a screwdriver and a crescent wrench would do in a pinch to fix almost anything on a car. And I'm way too cheap to just take it over to the Jaguar dealer.

So thanks a bunch to Steve and Dennis, and to anyone else who thought about my problem. I'm sure I'll have more eventually. Right now, I'm going to reassemble my car and get back to enjoying the heck out of it.

Mike out