Car would not start again. Found 5 Amp fuse (I believe #6) that feeds the visor lights, key transponder, and the latch blown again. I found that the red and black wire to the latch are shorted together.
Neither is shorted to ground. The red wire is fed with positive voltage and the black is 11 ohms to ground.

To troubleshoot, I cut the feed to the black and red wires and plugged the latch plug back in. Then replaced the 5 Amp fuse. The car runs fine but when you try to open the convertible top the latch will not release all the way even while helping with an allen wrench. It seems as if these wires feed a lock or solenoid inside the latch itself. Any ideas?

I can't work on or look at the latch unless I can lower the top. Thanks

 

I think we need a bit more information .................


What year ?
Which fuse box (there are five) ?

 

Here is a picture of the plug that feeds the convertible latch. Concern is the red and black wires on the end. Function of these 2 wires and or a way to open the latch entirely to lower the top would be very helpful.

 

Sounds like I need to push down on the convertible top mechanism in the back like in this procedure JagRepair.com - Jaguar Repair Information Resource

That will release the top to go down. Wonder if I can lie jump a switch to make the top go down? My hoses are in good shape

 

Sorry Oak but please give us more information to work with :


Year ? (wiring colours changed on a regular basis just to keep us all confused)
When you say "latch" - where is that ? I don't recognise that plug from your photograph.
Gus is the roof guru - maybe he will be along at some point with much better advice than I can give.

 

Sorry. 2000 XK8 convertible.
Convertible Top latch over the rearview mirror.

I found this drawing.


It shows micro switches. My question would be isn't a micro switch a short just like I'm seeing between the red and black wires?

 

Sorry - not a very clear scan, but you can see the whole diagram at Gus' excellent site www.jagrepair.com
Looks like the connector is RF4 (only 6 way white anywhere near that location) but colours don't seem to match yours so can't be certain.

This would seem to be connected to the 'Top Closed', 'Top Latch Closed' and 'Top ready to latch' switches above the rear view mirror.


If you can get the roof down using the method you previously described, then it could be that things will sort-of reset themselves - otherwise there's a fairly complex fault-tracing job ahead or you.

 

I am not sure why you cut the wires repairing is the best thing to do. The latch has no electrical function it is all hydraulic the only electrical function is status of the mechanical function with micro switches. As for any manual operation of the roof you must open the petcock on the pump to release the hydraulic pressure. I would suggest splicing and repairing the wires open the roof latch and open the roof. To open the roof you must open the latch unlock the rams on both sides and lift the roof with 2 fingers. If it does not open go back to the rams and unlock them once it is open park the latch close the petcock. Once that you have that done do a hard reset and then operate the roof closed electrically.

Gus
www.jagrepair.com

 

I will try to lower the roof and check the switches.

I cut the wires to isolate the problem and I didn't know how it worked. I can solder the wires back no problem. But if I hook the wires up the wires will draw 20 plus Amps and pop the 5 Amp fuse immediately. That is what I really don't understand.

 

You need to find the problem so it will not happen again before you refuse or it will keep blowing the fuse.

Gus
www.jagrepair.com

 

I was an idiot. There are two plugs by the mirror which are identical in size. I had the latch and the center roof console backwards. Switched them, fixed wiring, and all is well.

 

 

Well that worked a few days. Now we have to plug and unplug those two plugs to get the top to go up and down. Ever heard of thid?

 

You may need to do a hard reset to everything back to preset configurations that is if you have all your leads connected correctly and no shorts. Any time you wish to unplug an electrical connection you should disconnect the battery fuse.

 

Ok. Is there a thread on that? Should I start with top closed or open?

 

Do the hard reset with the roof open.

Link to hard reset JagRepair.com - Jaguar Repair Information Resource

 

I worked on it some today. Tried hard resets while in the closed and open positions. Top doesn't work properly. Windows do though. I even tried turning the valve on the pump while in the open position. I pushed down a little on the top to make sure it was all the way closed and used an allen to hold the latch closed on power up. Then tightened the valve and tried. Didn't change anything.

Only plug you have to plug/unplug is the connection to the latch. While open you have to unplug it to get the top to move. It will move all the way forward but not latch. You then have to plug the latch in and the top will close and latch properly. Weird
It's either a sequence problem or a faulty limit switch.