dh53

Trying to troubleshoot the power roof not working. Does anyone have a diagram for how the relays on the motor/pump assembly are wired to the motor? My thinking is to bypass the relays and directly power the motor to see if it is operational before I start taking the top off to get to the motor & pump. I need to know which of the 6 power pins (obviously not the signal pins) in the 2 relays connects to the motor.

I have the Bentley manual with nice wiring diagrams but this wiring isn't shown as it is internal to the motor & pump assembly.

I am looking for something like this picture which I found on the internet but this is NOT from an Audi.

dh53

Poking around with a multimeter I have confirmed the wiring is the same as that diagram, the two relays each has pin marked 30 normally closed to pin marked 87a. Both pins marked 87a are chassis ground. When one of the relays is activated it connects pin 30 to pin 87, which is battery voltage. One relay is activated for the top going up, the other relay for the top going down.

The control module works, all sensors that report to the control module work (i.e. latch sensor, top cover detection switches), the switch for the top works, the relays get energized correctly, the relays test out fine on the bench, the top moves freely up and down when I energize the motor manually with 12 V, the fuse is fine,...but still the top does not operate. I'm stumped.

dh53

Anybody have experience with a power convertible top that doesn't work?

-the top moves up and down freely if I do it manually
-the top moves up and down freely under power if I jump power and ground to the 2 relays on the motor/pump
-the switch, the sensors and the control module are working because when I activate the switch the relays click
-with the top up the top relay activates, with the top down the bottom relay activates
-the relays work fine on the bench, I tested them up to 10 amps current
-the convertible fuse is fine
-when I measure current through the fuse I get zero under all conditions
-when I measure voltage at the relays I always get pin 87A is chassis ground and pin 87 on each relay is always about 11.5V, or 1 Vdc less than the battery (WHY less???)
-when I activate either relay, pin 30 should make contact with pin 87 and so should be 11.5 Vdc or something close to battery voltage but it goes to -10 mV ?! Consistently negative, consistently -10 mV, this does not seem to be just the meter floating around near zero.

So the motor works, the pump works, the relays work, the fuse is good, and the switch activates the relays correctly but the top doesn't budge??

dh53

Following up in case anyone has a similar problem, mine turned out to be the positive wire at the 6 pin connector to the motor & pump assembly. The wire was so corroded it had failed and was only connected by a couple of strands of wire which is why it was so vexing, I could measure battery voltage so it appeared as though the wire was OK but it clearly could not pass enough current to run the motor. The connection was broken just where the wire meets the connector so there was no way to pull the terminal out of the connector, I had to solder on a new wire and bypass the connector. Works great now.

Daze67

I know this is a very old post but it is the closest i have found to the issues i have now, the only difference is i'm not getting any clicking from the bottom relay but i have swapped them around and still have the top one clicking and nothing at the bottom one.
After reading this i will be removing the connector and fingers crossed i have the same problem.

dh53

I wish you good luck, it was a frustrating job for me but years later the power top still goes up and down. A couple things I recall: I bought a set of generic 12VDC, 40 Amp relays with connectors and "pigtail" wires about 6" long for only a few dollars on eBay (picture attached). It proved useful in bench testing the 2 relays on the pump&motor so I knew they were good. I'd offer to send you one but honestly you can buy them from eBay with shipping for less than I can ship the ones that have been in my tool box for years.
Here is an example on eBay.

My fix was to remove the corroded spade connector in the plastic connector body and cut the wire, then splice in a new wire with a new spade connector from the cheap relay harness. I wanted to solder the new wire to the original wire and couldn't see a way to do that in the confined space by the motor so I removed the driver's seat and spliced in the new wire just behind some piece of body paneling behind that seat. It ended up being maybe a foot and a half of wire that I replaced just because that was where I had easy access to solder and shrink wrap the fix so it was as good as new.

Daze67

Thank you 👍 hopefully I will get time after work tonight to get the motor un bolted so I can check the connector.

Daze67

Exactly the same as yours, now i need to find where it goes so i can replace the wire 🤔