Started up the jag went to raise the top and the car shut off? Really!
I've been chasing a no start and clicking from a relay in the trunk after I turn the key back to off now this. What next?

 

Chafed wire, shorted out? 12 yr old car... stuff happens

 

Look at the charging gauge, and try to duplicate the problem. I think it may be that the system voltage dropped below 9.5 volts, where the ignition would shut down. It may be something as simple as dirty battery connections, a loose ground cable, or as involved as an alternator, or other charging system problem. Putting the roof up and down draws quite a few amps, and I can see this happening......Best of luck.....Mike

 

Why would the engine need to be running to raise the roof?

 

Yes check the battery and its connections. When you were dealing with the relays in the trunk did you swap them if so then you moved your problem to another location that may have contributed to your existing problem.

 

Because without the engine running you are working off the power in the battery alone and if the battery is already weak there could be a problem opening/closing the top. When the engine is running you are getting power off the alternator. Some folks intentionally open/close the top without the engine running to reduce the pressure that the pump delivers so as to protect the hoses.

Doug

 

It would make sense to address the root cause then. I think that's the OP problem. Starting the engine just to raise the roof leaves the battery worse off than not starting it as the alternator does not have enough energy and time to even recover from the starting exercise.

 

Operating the roof with the motor running or not is not a problem but many argue on both sides and I really do not have a problem with either operation. However, if you have a weak battery or one that is on the edge it will make for a bad day.

 

Get out of the car and insert the Ig key in the door lock and turn all the way to the left (I think that's up, if not turn it the other way) HOLD the key all the (either) way. The top should either close or Raise. If not, you more then likely have a bad battery. Put in a new one and I bet you'll be go to go on both counts.

Cheers

 

In thinking this through, it's worth keeping in mind how much, or rather how little, load the convertible top motor puts on the battery. It's comparable to the headlights; so raising or lowering the top is roughly like running the headlights for 30 seconds.

A battery that can start the car should not have any trouble with this.

My guess is that there's something else going on.

 

Operating the top with just battery, car not running puts less pressure on the hydr system of the top? How much of a diff it?

 

Pretty small difference, something less than 50 psi change in peak pressure.

That the peak pressure is so insensitive to voltage makes a lot more sense now that we know the pump has its own internal pressure control valves. These tend to make the pump sort of "seek" a peak pressure near 1600 psi.

 

Interesting point Dennis. That may explain why when I experimented a few years ago with a high frequency PWM drive to control the pump pressure I was getting low frequency (< 20Hz) hydraulic oscillation in the pump circuit that I did not understand.

 

Thanks for the replys. The car started up and ran till warm. Got in to leave to my journey and decided it was to cold for top down riding. Pushed the top up button and the car shut down.
I've been having a problem where I go to start the car and nothing. I turn the key to off and the clicking in the relays starts. I then have to disconnect the battery to make it stop. If I do a hard reset( hold the neg and pos together) it starts up and runs fine. This has been a problem for awhile. Checked all connections near the battery. Replaced the battery and had the charging system checked and all is well.
The battery was replaced last month.

 

Seems likely to me. Can't say I can picture exactly how the interaction would go, but between those valves and a PWM signal we could have the elements of some sort of feedback loop. That plus the fact that the oscillation was not seen with a DC drive ...

 

Loxmth,

Can you identify for us the particular relay in the trunk that is clicking? Or at least the neighborhood? Take the covers off of the electronics boxes in the trunk to do the listening. You might be able to feel which one it is with your fingers too.

 

When standing at the trunk battery to the right its the box between the battery and the taillight. In that box it's the two relays at the top right of the box. Also some clicking under the hood but I haven't found out yet.

 

earth fault?

start with the earth strap on the engine, then look at how good the earth is in the trunk

(I have no idea where these are yet, but it is a classic issue with older cars)

 

To bring the revs and voltage output up . Like the speed of the top going up or down.
Have new hoses and all three rams overhauled with upgrade seals... No green splatter worries. Rich