Targa Roof - possible reason why at times the roof opens slowly
08-15-2011, 04:33 PM
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Targa Roof - possible reason why at times the roof opens slowly
Once in a while, my Targa roof would just slow down and stall on opening and closing. It was random, and I have seen other reports on the list about this issue.
Recently, my main roof totally stopped opening, but the visor would work slowly. It turned out to a series of problems (including adjusting the microswitches for the blind so the system understood the blind was open), but most of the problems were around the controller. So it was time to dig in to that unit (it comes apart easily, relatively simple dual sided PCB).
The controller has five relays. One relay is dedicated to the blind, and the other four are for the main roof. The main roof relays are grouped into two pairs, one for each of the two motors for the main glass roof (and visor). If any of the relays fail or have worn contacts, then only one of the motors will be activated, and the roof will just crawl. The relays themselves have one default set of pins connected with not powered, and when powered it switches to another contact. The roof logic essentially works like a three way lighting switch, with only two relays of the four activated to power the roof in a particular direction. The other two relays are also in the circuit, but their default connections are being used.
On my board, I had one relay go bad where the contacts active in the activated state were blown (I replaced all four relays anyways just in case). The characteristic is that the roof would open very slowly, but close fine. That was interesting in that they were soldered AND glued to the board, so I ended up cutting the relays apart down to the spades left in the board, and I desoldered the pins out. The relays are readily available at around $3 each.
Here is the pile of cuttings when I was done cutting out the relays and desoldering the pins.
Stripped Board - Upper Side
Stripped Board - Bottom Side
However once that was done, i still had a problem opening the roof, so I had to check some more, and I found a bad plate through hole in the board. This provided the common ground circuit to a pair of the relays. They are passing a lot of current through a small plate through hole, so that could fail under heavy load. I think this was a fault on the board and not introduced by my soldering/desoldering, but anyways I supplemented the board with a piece of wire and it now works perfectly.
So, if you occasionally get slow roof operation, its almost certainly because only one motor is driving the roof. If it's in the controller, it could be:
Anyways, my roof is working 100% now, so I thought this might interest the Targa community.
All repaired!!
Cheers,
Mike
Recently, my main roof totally stopped opening, but the visor would work slowly. It turned out to a series of problems (including adjusting the microswitches for the blind so the system understood the blind was open), but most of the problems were around the controller. So it was time to dig in to that unit (it comes apart easily, relatively simple dual sided PCB).
The controller has five relays. One relay is dedicated to the blind, and the other four are for the main roof. The main roof relays are grouped into two pairs, one for each of the two motors for the main glass roof (and visor). If any of the relays fail or have worn contacts, then only one of the motors will be activated, and the roof will just crawl. The relays themselves have one default set of pins connected with not powered, and when powered it switches to another contact. The roof logic essentially works like a three way lighting switch, with only two relays of the four activated to power the roof in a particular direction. The other two relays are also in the circuit, but their default connections are being used.
On my board, I had one relay go bad where the contacts active in the activated state were blown (I replaced all four relays anyways just in case). The characteristic is that the roof would open very slowly, but close fine. That was interesting in that they were soldered AND glued to the board, so I ended up cutting the relays apart down to the spades left in the board, and I desoldered the pins out. The relays are readily available at around $3 each.
Here is the pile of cuttings when I was done cutting out the relays and desoldering the pins.
Stripped Board - Upper Side
Stripped Board - Bottom Side
However once that was done, i still had a problem opening the roof, so I had to check some more, and I found a bad plate through hole in the board. This provided the common ground circuit to a pair of the relays. They are passing a lot of current through a small plate through hole, so that could fail under heavy load. I think this was a fault on the board and not introduced by my soldering/desoldering, but anyways I supplemented the board with a piece of wire and it now works perfectly.
So, if you occasionally get slow roof operation, its almost certainly because only one motor is driving the roof. If it's in the controller, it could be:
- one or more failing relay(s) so only one motor is working
- A bad plate through hole.
Anyways, my roof is working 100% now, so I thought this might interest the Targa community.
All repaired!!
Cheers,
Mike
