Vincent C.

you need to install the 993 top control unit then update the wiring for the control unit....its quite easy to do.....vinnie

BigMikeATL

I just got confirmation that this is in fact the proper way to do it. See the wiring diagram that is posted earlier in this thread. I'm going to do it this weekend.

Is the control unit under the dash or floorboard?

BigMikeATL

The 993 unit was a replacement by the factory under TSB 9613 which has the instructions. The downside is that a 993 control unit is over $600. I'll tie a couple wires together instead.

So that could be the mystery as to why some 964"s work like 993's - the control unit was replaced.

BHMav8r

Update ?

BigMikeATL

I keep putting it off because the control unit is a bitch to get to. The ignition switch wires and another module is in the way to get to the convertible top control module. It's still on the list of things to do.

BHMav8r

I thought you were just going to "jump" the original relay/wires ?

I usually keep the top down most of the summer, but as cooler weather approaches . . .

Thanks for keeping us posted.

BigMikeATL

I am but I have to get to the green/white wires which is a bit challenging. I'll have another look this weekend.

BigMikeATL

Completed the mod yesterday.

I removed the driver's seat to get my big *** under there. I removed the VDO gauge module and then the convertible top controller. After I removed the top controller, I realized that I could have probably just pulled the end plug off that contains the Green/White wires.

The job would be the easiest if the lower dash was removed but that seemed excessive. I wish I had a buddy that is about 5'8 or smaller with very small hands. Probably would have taken 20 minutes. Instead it took me hours.

Love the mod though. The top light comes on each time the car is started like most said it would. The top button has to be hit in order for it to go out. I'll probably just remove the bulb from the clock.

jimq

mine must be wired different because my light doesnt come on unless it is not locked down tight. I need to pull mine out and check the joints because sometimes it stops on the way up or down and I have to let off the button and push it again. When I get it open I will take a picture of the wiring.