So, when my latch hoses leaked I capped off their ports on the pump and have been operating the latch manually and letting the pump lower and raise the top. I lowered and raised the top several times over the course of a few days. Now this afternoon the top refuses to move after I open the latch, even if I push upwards. I can free it from the latch by pushing up but there is a lot of resistance and I am afraid to push any harder for fear of damaging the rams. Checking the pump in the truck while my wife operates the switch, I did not hear any sound indicating the pump was working. I do hear a relay click when the switch is pressed but that's all. Fluid level is fine. I'm hoping I blew a fuse, but I am not sure which fuse I should be checking. Any advice would be welcome. Thanks!

 

You will not damage the rams but you can bend the roof frame so my suggestion is to not force it open.

The roof not moving is telling you that the rams have not unlocked the roof linkage. Have the rear windows dropped and Is the roof motor operating at all in your efforts to open the roof?

 

Did the rear windows go down when you began the "lower top" operation? The system won't try to run the pump until they are down. Remember ignition switch set to on or accessory before beginning a "raise" or "lower" operation.

What happens if you push the rocker switch in the "raise top" direction?

 

The rear windows go up and down as normal. Have tried with key in "on" position and also with engine running. Latch fully opens. I can push top out of latch but that's it; it does not jump up to the opening position as it would if all were normal. The top won't budge when switch is pressed in either direction. I can't hear the pump nor can I feel any vibration when I put my hand on it as my wife presses the switch, so I am assuming it is not working. Admit I have not yet checked to see if the pump is getting current. I am hoping it is just a fuse, although why the fuse would blow is another concern (and 'm not sure which fuse I should check). I am very careful not to force anything. Bummer because it was working so nice the last time I used it on Saturday.

 

OK, far as I know there are no prior reports of this so we'll have to sort of feel our way.

If I'm picturing things right, the top is now in the position where it was "parked" by the system prior to closing it with the (manual) latch. It's normal that it doesn't want to move up and back from there without the pump running (or the petcock open). Trapped hydraulic fluid prevents it.

Suggestion: Let's get the system to a "standard" position and see if it will go from there. Use the rocker to close the rear windows, pull the top closed with the manual latch, set ignition switch to off.

Now try the standard "lower top" sequence ... ignition switch on, open latch fully, press rocker in "down" direction. The pump should run.

If it does not, I would then open the pump's petcock and black/white power connector and -- just for an instant -- apply power to the pump to see if it runs. Either polarity is OK for this test.


Let's see where this takes us ...

 

What I found today is I am blowing the pump fuse as soon as I press the switch. Latch is definitely opened all the way. Wound up blowing five fuses testing it. Makes no difference if petcock is open or closed. Fortunately the quarter windows work fine. So I guess I'll be looking for a short at the pump wiring.

 

Suggestion: Open the power connector (black & white wires) to the pump. Does pressing the switch still blow the pump fuse? This will tell us whether the problem is upstream or downstream from that connector.

 

Thanks, Dennis. Yes, I did try that and found the fuse did not blow when the wires were disconnected. Looks like I have a pump problem. I am hoping that when I r&r'd the pump, I pinched a wire and caused an insulation break. Weather preventing me from getting deeper into it since I don't have a garage. Of course, I wouldn't want to drop the top in the rain, anyway!

 

Finally got back into trying to troubleshoot my convertible top's habit of blowing its fuse.Here's what I found: The 40-amp fuse blows as soon as the “top down” switch is pressed. Does not blow on “top up”. Windows operate up and down as they should. When I disconnect the pump power plug and press the down switch, the fuse does not blow. If connected, the fuse blows. When I disconnect the yellow solenoids plug at the pump, the fuse does not blow. If reconnected it will blow instantly. A fused 12-volt line from the battery right to the pump (with solenoids plugged in) blew the fuse instantly. When I first pulled the carpeting away to reveal the pump I found in repositioning it, the wires to the blue (latch) solenoid got stretched and were under tension. The wire cap had opened and the two wires' connectors came close to one another. I can’t say if the two wires touched when live. I don’t know. Probably it has nothing to do with thee problem, anyway. But I wondered if the solenoid had somehow shorted out might it cause the pump fuse to blow. Could the solenoid be jammed. What happens if you remove one? And is there any way to unplug them? Any help will be much appreciated. The summer is slipping away!

 

Not sure I follow here. Did you apply power only to the black/white pump connector or was power applied to the solenoid connector as well? Car turned on or off?

With the car turned off, petcock open, if you open and apply power directly to the pump white/black connector just for an instant, does the pump run? Try this with both polarities.

 

Car off, no power to solenoids. Direct connect from battery to pump blew fuse. I have to try reversing the polarity to see if the pump reverses or just blows the fuse again. Right now, there is no reaction from the pump except to blow the fuse.

 

I hope I'm wrong about this. If you're testing with nothing but a fuse between B+ and the pump's black/white connector, then it seems inescapable that the pump (or its connector) is bad. Very rare ... it's almost always some other component that's in trouble.

Anyone know if the "motor" side of the pump can be opened up without disturbing the "hydraulic" side? I think one or more of the vendors who supply convertible top hoses also does work on the pump.

 

top hydraulics will refub the pump/motor - see below link

Rebuild/Upgrade Service for '96-'06 Jaguar XKR/XK8 Hydraulic Pump - Top Hydraulics, Inc

 

Or ...

97 98 Jaguar XK8 XKR Convertible Top Hydraulic Pump Lift Motor HJA822 16530 | eBay

This is crazy-cheap and guaranteed 6 months.
There might be some issue with the type of solenoid connectors. Varies with MY? I forget. Should not be a deal breaker.

(The description says it fits coupe as well as convertible )

 

That would be a great bargain, but it isn't compatible with MY 2005. Bah. I sent a question to Top Hydraulics describing my symptoms and got the following answer from their Klaus Witte:
"It appears that the electric pump motor is about to fail. It should never blow a fuse. You are witnessing a temporary phenomenon where the motor does not draw too much current yet for part of the cycle. That will change. The pump has to work harder (produce more pressure), that's why the fuse doesn't blow yet when only the circuit for the front locks is activated." Sounds reasonable. What confuses me, though, is that the fuse blows even if the petcock is open, which should result in near zero back pressure. Haven't tried reversing the polarity yet to see if the pump operates in reverse. But no matter, it does not look promising for a DIY fix.

 

I think the MY difference is just the type of solenoid connector ... memory fuzzy on this. Anyway that EBay pump is just too good a deal, so I bought it. If you decide it will work in your car and you want it, I'll pass it along at same price.

The explanation you received is a bit mistaken on the current draw of the motor. It is maximum at zero RPM, and independent of any mechanical load on the motor. This "starting current" depends only on the voltage and the "static" resistance of the motor. Reverend Sam (I think it was him) measured this static value some time back ... it's about 0.4 ohms as I recall. So with 12 volts applied, max current would be something like 12/0.4 = 30 amps (less if a resistor has been added to the circuit).

 

Dennis,
That's a very kind offer. And if I can determine that the only difference is the solenoid connectors, I will probably take you up on it. Just having trouble accepting that my pump motor went bad literally overnight. Never slow or sluggish. Just didn't work one morning. Hope plugging the latch hose ports had nothing to do with it. Just need to do a little more fiddling.

 

Operating the pump with the latch ports capped isn't harmful to the motor. If anything, the manual latch procedure lessens the work the motor has to do.

It's possible that while installing the caps you stressed the black/white connector & wiring, and made a short somewhere. Maybe worth a look there.

 

I'll be gone for a couple of days on a short motorcycle ride, but will be getting back into my pump when I return. Have to pick up a new multi-meter. Mine has crapped out.

 

if the pump runs its not bad. I didn't see the hydraulic schematic but if there are two solenoids on the pump, one is for up and one is for down. Reversing the polarity will make the pump run backwards and it won't pump oil. if you are running the pump and not actuating the solenoid you will dead head the pump causing it to blow the fuse. you stated the fuse didn't blow when pressing the up button if the pump is running and the top does go up then this means your down solenoid is bad or not actuating for some reason.........