Folding Roof Hydraulic Pump - Motor Unit only

[Batmobile]

Hey fellow XLR commune,
I was writing about this in reply to another thread, however, due to age, figured I'll add and write it separately.


Had a problem with the roof hydraulic pump 2/17/22. Due to my own inconsideration, by continue to hold pressing the roof switch for more than necessary while it was stuck in sequence.

My Folding Top sequence had always been to let go of the button on the last step, and then hold it again for the sequence to complete. The last step where the full trunk lid goes down, and in reverse when the lid is going up.
I figured one of the sensors (potentiometers) is out of spec and thus why I need to let go, then hold the button again for the sequence to come to an end.

Not yesterday. While I was holding the button through the sequence as usual, the top stopped where it usually does - but I didn't take my finger off the button - I kept holding the button for about 15 seconds, when it didn't go anywhere, I let go of the button then press it again and the sequence went just fine.

I go on my marry ride, reach the destination and put the top up, (not holding on the button this time) all goes fine.
Problem starts when I get back into the car 20 minutes later, I smell a strong burning odor of plastic coming from the trunk are where the hydraulic pump and control modules are. After a quick visual inspection, I see no leakage or damaged wires/connectors. Get in the car, try to operate the FT and I get an error on the dash "Top too cold to move". I hope for the best and wish a morning start would be back to normal. Not the case.

I checked DTC, and found "B3670" Pump Motor Temperature Sensor Circuit.
Which right away confirmed the smelling burnt plastic odor was coming from the bottom of the hydraulic pump, and meant the thermistor was in question.

ccclarke, the legend, goes over the thermistor and its functionality. Basically it checks the pump motor temp and makes sure its' within spec every 300ms to ensure safe and proper operation.
However, GM pulled a short one here, you'll need the full new pump for $1,500. The thermistor is housed within the motor unit which is covered by the plastic black tube. GM didn't offer the motor unit separately.

Next to the dealer, came TH, or "Top Hydraulics" according to many other XLR owners' feedback had a fantastic experience. Klaus is on another level.
They offer a hydraulic pump rebuild for $800, which is not bad given the dealer option.

For my problem, it seems that I only need the pump motor unit, as my top worked ok before that melted. I took it apart today 2/18/22. Confirmed the smell came from the motor unit, and can barely see melted electronic parts inside.

For this, I found a cheaper option, which is for a motor pump replacement only.
I came by this site, and will most likely give them a try.

Cadillac XLR Roadster Convertible Roof Motor Unit Only 2003-2009 (88958028)

Cadillac XLR Roadster Convertible Roof Motor Unit Only 2003-2009 (88958028) Roof motor failed? We supply reconditioned units with a 12 month warranty

roofmotors.co.uk

Has anybody had any experience with the company previously? Or will I have to try it out


Cheers and thanks.
O

 

[mickeytee]

you can buy a pump motor like that on ebay for 50-60$ us. Its not the quality of a GM part but its replacement that will last a year or so. The problem is The motor overheated and something caused the damage. Without finding and repairing the cause the solution of a new motor will be short lived. Same motor is used on BMW SAAB and dozens of other cars. I miss old Clark He used to be able to write 4 pages on how to turn your headlights on.

 

[Batmobile]

you can buy a pump motor like that on ebay for 50-60$ us. Its not the quality of a GM part but its replacement that will last a year or so. The problem is The motor overheated and something caused the damage. Without finding and repairing the cause the solution of a new motor will be short lived. Same motor is used on BMW SAAB and dozens of other cars. I miss old Clark He used to be able to write 4 pages on how to turn your headlights on.

Hi mickeytee,
Unfortunately all did not go as planned. Appreciate your support if you can help me troubleshoot this.

So I received the remanufactured pump, which is a great piece of kit. The removal of the old motor unit and installing the new one was a piece of cake. Problem is as soon as I plug the power cable (red and black) which I'm assuming is power to the pump the pump motor starts "trying to turn" the opposite way which puts pressure on the motor. So I unplugged it quickly to avoid burning the motor like the first time.

Attached some photos and a video of the issue. Appreciate any input.

Many thanks.

 

[Batmobile]

Here is a video I just took. You can see when the pump valve is loosened, you can hear the motor move freely.

So it seems to be stuck in trying to move in this direction. How to remedy this? Maybe a fuse blew along when the old motor burnt up?

 

[Batmobile]

Today I took out the FTM (folding top module) to have a look and see if anything is fried inside. I will be taking the module to an electrician to test out the board.

I made this hunch based on a similarly reported problem by one of the members on the forum. Their pump was stuck to the "Direction A" position, and GM recommended an FTM replacement - similarly my pump is also stuck trying to run when I plug the FTM to it.

Power top pump motor runs continuously

2006 XLR base with 75K. Top Hydraulics rebuilt pump installed and working great from June 2019 to November 2019. Today while putting the top back up after a warm day all was fine except once fully closed the pump motor kept running. I decided to drop the top and see what would happened, top...

www.xlr-net.com

I plugged power only to the pump, and it did not start. However if I plug in the FTM when there's power the motor starts to run continuously. Seems like the same fault our friend had and they remedied using a new FTM.

I'll take it over to the electrician and have them check the board and change any relays if needed and report back my findings.

 

[mickeytee]

well at least your module looks pretty clean and dry so there is a small chance the relay may be stuck. I repaired one and it lasted about 2 weeks before another relay went out .I replaced that one and it lasted 2 days so I replaced the module. we have had dozens of owners over the years send these out to be repaired to maybe 20 different shops and most of the time they cannot repair them as the computer chip fails and you would have to be able to read it and reprogram it which takes about a 100,000# machine from what I have been told. good luck and hope it works. AT least the relays are easy to check and the yare very cheap and pretty easy to find.

By the way the factory repair manual gives you about 20-25 checks to do on the top assembly and almost every one of them says does this work? if not replace the FTM . that is pretty much their solution for anything that fails on the top.

 

[Batmobile]

It is indeed a pleasure to have your company around the forum. You sir hold a treasure of knowledge and deservedly should be thanked for your spirit to share and help out a stranger in need.

Is it only a matter of testing the relay and swapping out the ones that show a faulty/different reading? (From the four relays on the board)
Appreciate any other insights you have regarding this, as am heading out first thing in the morning to take it to the electrician who's only seen it via mobile photos - and asked to bring it over.

All four relays look visually okay and no mark of heat or burn. However, it seems the relay working pump on direction A is stuck. Attached the wiring diagram I could find, appreciate anything else more specific you can find or have referenced to.

From the diagrams:
Folding Top Module C3 Connector end view
Pin "M", wire color "D-BU", circuit no. "5949", function "Pump Direction A"
Which relay is on 5949?

 

[Batmobile]

Had the relays on the board tested today. The technician visually spotted the bad one in 3 seconds. (that's how it pays to know your stuff)


We then tested the relays, and found the culprit to be a shorting relay, the bottom right corner when looking at the board with relays on left hand side. These 4 relays are all "HTB2-160, 12V" and are available online for cheap. My tech doesn't have one on hand, so he will attempt to fix using a coil/inductor to have it ohm out the correct reading.

The last piece of information, which was most critical - was kindly provided by mickeytee.
The relays have total 8 mounting points on the board, 4 connectors and 4 mounts. The 4 connectors come across in a row. The outer points should measure .320 ohms. Inner points should read zero.

Will post an update once I receive it back and test it.

 

[Batmobile]

I am happy to write that my folding top is working normally as it was before the motor burnt.

Burning the motor meant another component received a hit. Next to the hydraulic pump lies the FTM module, the brains for the roof operation. This module houses 4 relays as mentioned previously.

After taking it to a tech, he fixed two relays - one was shorting and the other was stuck. Did that and replugged in everything and the motor was silent, finally! Went inside, performed window index, and started to open the top. It seems the operation was much smoother than any other time I've seen it. Top opens and closes as it did before. However my trunk remains inoperable by the button or by the latch.

Figured trying to fix it is not worth it. Even though I love the car and appreciate it very much - it's time for her to go. Dealing with these intricate situations, and having the knowledge & parts for this car without being in the U.S. is extra costly and a damn headache. Kind of feels like protecting a Fabergé egg, you love that egg - yet it's so fragile. Cost of owning an XLR-V, they are damned unique cars.

A special thanks to, mickeytee, couldn't have done it without your supportive spirit.
Let this be a reference, anyone with a similar issue can save $$$ on a new FTM module.

Cheers,
O

 

[The Don]

Where did you find replacement relays? Looks like I'm having the same problem!

 

[Bryxlr]

you can buy a pump motor like that on ebay for 50-60$ us. Its not the quality of a GM part but its replacement that will last a year or so. The problem is The motor overheated and something caused the damage. Without finding and repairing the cause the solution of a new motor will be short lived. Same motor is used on BMW SAAB and dozens of other cars. I miss old Clark He used to be able to write 4 pages on how to turn your headlights on.

What happend to clark