Hi all,

A little more advice would be most appreciated, the roof of my 1999 XKR convertible project is not working as it should.

After reading the "convertible top electrical system" pdf it says one of the the faults could be "top latch closed, switch is short circuited":

Where do I get a replacement from?
will replacing it stop the short?
would someone mind spelling out where it is?

Thanks in advance.

 

I just ran across your post. I see that no one has responded yet. It could be that we are not quite sure what you are having problems with. You said the top is not operating correctly. Where is the top operation is it failing? Not releasing the latch? Not going down? Not going up? Not latching? Trying to figure out why you are looking at a switch fault. The latch switches should be on the latch cylinder in the windshield header. More information would be helpful in getting help to you. Best wishes in getting this resolved.

 

When I put the roof down button the rear quarters move down, the roof unlatches but only moves an inch or two.

The top will not close and latch up which means the quarters are stuck open, When going the the pdf. It explained it could be the top switch or a short circuit.

Does this sound right to you?

 

Not necessarily. If I'm reading your description correctly, the top is not going down, so you are trying to close it back up? If this is the case, the first thing I would check is the fluid level in the tank. Low fluid will cause the hydraulics to not work. It should be at or close to the top line on the reservoir. The fluid is Pentosin CHF 11S, green can, available at most parts stores. If it is low, the fill location is on the top of the reservoir. Some people use a syringe attached to a hose to fill, I used a bottle pump that had a hose on it.
it's much easier than removing the pump to fill. If the reservoir is below the bottom line, then you may have a leak in the system. Look for fluid around the pump fittings, pull the rear seat cushion up and look around and under the matting for fluid, this would indicate ram fittings or seal leak. Look at the light cluster on the windshield header for fluid from latch hoses. These are the most common places for leaks. A major fluid leak on the rams may also drip outside the car in front of the rear wheels.
While you are in the pump area, examine the hoses coming off the pump. If the black hose coating is crumbling, you may want to consider replacing the hydraulic lines in the near future before the latch line fittings fail giving you the famous "green shower", which will happen if the oem lines have not been replaced. It is quite common.

You should be able to find "how to's" in the sticky section of the forum.

When the top button is pressed there is a specific sequence of actions that take place when the top button is pushed, all controlled by inputs to body processing module and the security and locking module from different switches, activating several relays and solenoids.

The sequence for top down when the button is pushed is
quarter windows lower
front windows dip if not already down
latch opens, (will stay open until top rams hit lower micro switch)
top lowers
latch closes

When pushing the top up button, the sequence goes like this
latch opens
windows dip if closed
top raises
top hits latch
top up rams hit upper micro switch (either before or after latch closes, as I am doing this from memory instead of looking at top operation chart)
latch closes
front windows raise
quarter windows raise

Knowing the sequence and what switches have to be made for next step to occur goes a long way in correct diagnosis.

If you have your owners manual avaliable, it should detail how to close the top manually. Quick version, access the pump in trunk above cd changer rack. Open the petcock (counter clockwise) grab the 10mm allen key that's on the side of the pump. To the right of the latch, so be a plastic plug, remove it, insert allen key at 3oclock position, turn to 6oclock to open latch, pull top into latch and close the latch. At this point the top will be closed, but if the ram is not fully extended to hit the micro switch, your quarter windows will not raise.
At this point, I would close the petcock and try pushing the top up button to see if the quarter windows will raise. If so, good, if not, there are 2 ways to get them up. One is to reach down into the right ram area and try to grab the ram and pull it up into "locked" position so the micro switch is made (then the top up button should raise the windows), or you can go into the trunk, open the fuse box cover, locate the left window up relay and the right window up relay and "jump" them individually to raise the windows.

Let us know what you find.

 

I see you also described this as a project. Has the car had water damage? If hydraulic fluid level is good, you may have water damage to the security module that is located under the trunk fuse box. You may want to pull it and open the case to examine for corrosion or burn marks from water damage. That is what happened to me.

 

Thanks for the really detailed advice Dcarlo I really appreciate your time.

I'm away on holiday right now but as soon as I'm back I'll be taking your advice and hopefully sorting the issue out.

Will report back.
Cheers

 

To be honest I don't know much about the car so water damage could have happened but I will definitely check the security module.

Thanks again Dcarlo.

 

Hi Dcarlo as you can see from the picture the levels are really low:


Apparently Pentosin CHF 11s has changed name to Fuchs CHF 11s, can I just top up the levels or am I going to need to empty the system first as I read that you can mix Fuchs CHF 11s?

Cheers

 

I would guess they would be the same. There might be a different opinion out there though. Here is my logic at this point. The hydraulic system is a closed system. If you are that low on fluid, you probably have a leak somewhere that needs investigated. At this time, I would add fluid to the top line or close, and test functionality. If the top works, then we know it was low fluid. Then the search for the leak starts. There are good instructions on this forum's how to section that covers replacing the lines, that was quite detailed in how to remove interior pieces to access what you need. I would look at the pump fittings, if good, then remove back seat cushion and look in the corners for wet spots. You may have to remove rear side panels to get to the rams to check them. I think you are getting close to proper diagnosis. Good luck.

 

Thanks for your advice Dcarlo.

 

Update.

After I filled the reservoir to the top line I had to press the roof close switch a number of times untill the top leached and the quarters closed, phew.

As advised I have a leak so I will be upgrading to better lines but unfortunately I have more urgent jobs to do beforehand so for now I won't be touching the roof opening button until I've upgraded the lines.

Thank you all for your help.

 

I'm glad we were able to help. Since you filled the reservoir, I would assume you did not see any evidence of leaking around the pump. If the latch fittings were leaking, you would see fluid around the headliner and in the light fixture there, this would be very hard to miss as it would probably be dripping on you. That leaves the ram seals and fittings. Under the front edge of the rear seat cushion, you will find two nuts, possibly covered by a vinyl cap. You can remove this and pull the cushion out to be able to check for fluid around the back corners. Replacement lines are readily available from several sources, Top Hydraulic's is where I got mine. A complete set of 6 lines was around $600 a year or so ago. The set of 4 ram lines are also available. Some of the sources also offer rebuilt rams if seals are leaking. My rams looked to be in good condition, so I only replaced the 6 lines. The 4 ram lines are fairly easy to replace once you remove the rear interior bits. There are some well detailed step by step instructions on this forum. For me the hardest part of the ram lines was getting to the zip ties and clips holding the lines along the rear seat bulkhead. The latch lines are a little more difficult getting them up the A pillar, but not terrible. I connected the new lines to the old lines and pulled them from the pump. It took me about 2 days to do it with about a month between removing the interior and installing the lines, putting back together. Most of the fasteners are torx so I would recommend investing in a good set for 1/4 and 3/8ths socket wrench.
Best wishes to you

 

As always Dcarlo your advice is excellent and well detailed, this tread is full of useful information that fingers crossed other can benefit from like I have.

Thanks again for all you advice. 👌👏