Anyone that has the GM auxilary hardtop for C-4 roadster. Where does the RW heating plug connect? My 89 did not have the hardtop option when delivered. I have to check the manual, but the wire connection should be in the harness, correct ? Where is the switch ?
Guess I have to do some research, but being in FL, doubt if the defroster mode will ever be used.

I have a GM hardtop on the way with the RW wires.
Thanks,
Boatman

 

The hot lead (orange/black about 6-8" long and a connector will be on the passenger side taped to a plastic loom and under the carpet piece between the pass side shoulder belt mounting point and the forward hinge pin of the folding top. If your car originally did not come with RPO CC2 (the hardtop), there will be no ground wire on the driver's side. It would normally be in same location on the drivers side.

Unfortunately, the CC2 option also got a different HVAC contol panel. The heated mirror button also ran the defogger for the hardtop. Apparently this particular panel had a different printed circuit to power the defogger. The button that controlled everything had a different design on it. The regular button showed a shape like the outside mirror housing while the one with the hardtop option had a square shape to it.

When I got a top for my 92, I found the wire, built a ground wire and attached to the body and tried to power it up. There was no power at the orange lead and that's when I started to figure out what was going on. The owner's manual has pics of the buttons and afte asking here, I found out that the panel was different.

The hardtop option was not installed on the Bowling Green Assembly but just a few blocks down the street at the company that provided the tops (American Sunroof??). Apparently the cars getting CC2 had the HVAC panel installed on the line so there was no extra electrical work to do at ASC.

One of the things done at the time the hardtop was fitted, was to make any minor adjustments to the door windows so that the hardtop and the softtop would have a good window seal. You may have to adjust your windows so that the top fits and the windows do not hit the frame when you close the doors.

 

Thanks for the info. My 89 has the heated mirrors. I do not see that as an option for 89 in Antonick's fact book. The car was GM exec owned for it's first 3 years, not titled.
I will check for the plug today, and am wondering if just plugging it in, that it will work off the heated mirror harness.
Being in South FL, it is not an issue, but will get hooked up anyway.
Boatman

 

Unless the car had RPO CC2 (look at the RPO listing under the console lid), the orange lead should not have power if you hit the heated mirror switch. That can be tested with a voltmeter so no need to install the top.

When I have my hardtop installed, I really don't get any fogging on the rear window. The windshield defroster operating and the fan on High will blow air back on the window.

You'll really like the hardtop. The car is quieter inside and all of the typical convertible squeaks and rattles go away. The car actually becomes stiffer than a coupe once you bolt the top in place. Unfortunately, the use of the storage area become very limited as the only thing that can go back behind the seats has to fit thru the opening.

If you didn't get the installation instructions, let me know and I can send you some scanned files of the original hardtop install instruction sheet.