98 Cabriolet top won't open or close

I bought a 98 cabriolet about a month ago. 104K miles. At first, the top worked fine. Then, it started acting up, and I had to unlock and relock the trunk several times each time I wanted to open or close the top. Once I got it to work, it worked flawlessly until the next time I unlocked to the trunk. Now, I can't get it to operate at all. When I hit the button to open the top, the back of the top will lift as normal, and the toneau will lift about 3 inches and freeze. No further movement. Also, if I open the top manually, and try to close it, the toneau will lift about 3 inches and stop, but you can still hear the motor churning.

Any suggestions? After dealing with this and several other small issues, I'm starting to regret buying this car over a '98 325i.

typically, the wires to the truck break at the flexing points. Remove the liner on the trunk lid to find them. They may be cracked internally and not be totally obvious. There are some pictures on other sites of how to split the bundle and use a meter to test the wires. It is not difficult. Do not be dismayed. Your problem sounds intermittant and that usually means wiring. When the system discovers a failure the top indicator light will blink. I'd be interested to know if it starts blinking right after the back of the top raises.

The top indicator light flashes when I release the top latch (obviously) and put the top down. It will continue to flash as long as the car remains started. This includes driving, parked, anything. If I turn off the car, pull the key from the ignition and restart the car, the light will go out as it should normally.

As you said, I do not see any obvious signs of frayed, split, or broken wiring, but I will look in the forums on how to test. I can see that the hydraulic fluid in the motor is not full. Because from time to time the toneau will lift just a little higher if hold the top button, then release, then hold again, I though maybe this could be a problem, but I am like you in that this seems more like an electrical thing. Thanks.

This is straight from The New Audi Cabriolet, service training booklet, self study program 221.

A Convertibel Top Indicator Light - K98- in the instrument cluster signals the following:
Steady Light
- During opening and closing operation
- If an opening or closing operation is interrupted by releasing the Convertible Top Switch
Flashing Light
- If faulty input signals or illogical switch signals are received by the Convertible Top Control Module.
- If a DTC is stored in the Convertible Top Control Module.

As you can see, your light is telling you something is wrong or you have a stored code. I have attached a picture of my backup pump. The min and max lines on the reservoir are on a slant as the pump sits on a slant in the car. The picture shows the pump on it's side for clarity. The reservoir is never totally full, and the fluid lines up with the lines. The 13mm bolt in line with my finger is the fill point. I doubt you need fluid unless you have a leak. The fluid is the same as the power steering fluid. Use a mirror and look at it then decide about the fluid issue. I'm still voting on wiring as your pump works. Maybe you have a bad solenoid valve, but the intermittant nature of the problem points the finger at bad wiring. Go to SJMAutotechnik.com and buy the manual I quoted. Best $15 I have spent.