LarsCarrera

I replaced my '01 Top with one from a 2005 Turbo Cab. The only difference that I could find is that the rear window is glass and larger that my original plastic window. It took me a day to do the switch but all the hardware was identical. I have watched the widow as it is being "stowed away" and it lays flat without problems. I have looked for any other obstructions and have found none. I tried to download a video of the situation but it did not work. The Top goes down to the point where the "clamshell" starts to close....then it just stops, pump still runs briefly. Any thoughts, ideas, etc. would be appreciated.

Thanks

Porschetech3

Check the position sensor on the drivers side cylinder behind the trim panel near the window regulator, make sure it is connected. If it doesn't "see" the top at full open position it will not close the clamshell.

ipse dixit

I think it's broken.

TonyTwoBags

You took a widebody cab top & put it on a narrow body cab car?

frisbee91

Was the top controller re-calibrated after the installation?

LarsCarrera

No electronics were touched (connected or disconnected)....it was purely a mechanical swap. The mechanicals on the old & newer tops were identical. The Top goes up & down fine, latches and unlatches fine.....just stops when the clamshell is about half closed. The pump changes sound and the end as if the Top were encountering an obstacle of some kind.......can't find it!

frisbee91

It is possible to screw up the calibration of the top without touching the electronics.

Here's a hypothetical:
Suppose you remove the old top when it's in the 50% open condition. Then, you install the new top in the 75% open condition.

Now, when you go to retract (open) the new top the rest of the way, it moves through 50% of its motion (since that's where the potentiometer was left on the old top), and the system expects the top to be fully open at that point. But it isn't. Still 25% to go. So it hangs up.

Consider that the calibration might be off.

LarsCarrera

Thanks.....makes sense to me. Only 165 miles to the Stealer!

Porschetech3

Did you check the sensor I mentioned in post #2? The sensor does not have to be removed or reinstalled when the top is removed, BUT if you don't hit the slot in the sensor arm when reinstalling the drivers side hydraulic ram, it will do exactly what you are describing.

LarsCarrera

Thanks........Tomorrow is "fix it day". Where can I find a diagram as I did not locate all of those limit switches when I replaced the top. I'll advise on my results............

LarsCarrera

Tony.....the seller did not say what the donor car was. He just said that it would fit my '01 (along with a bunch of others). When I got the Top..."2005 Turbo Cab was written on the frame. I measured, very carefully, and they were identical.....the only exception being the larger "glass" window. https://rennlist.com/forums/graemlins/nono.gif

LarsCarrera

OK....I got a good lead from a fellow Renn guy. He said that my small plastic window was meant to fold as it retracts.....and that's why my top won't close all of the way. Then I found this 2000 with the same glass rear window that I just installed. I couldn't get any info on it....but, geez, it must open & close, no? Still stumped. And...no bad relays.

KoB

I can't help with your problem, but I had heard the same thing about tops. Specifically, I remember reading that the frame mechanism of the 996.2 is different from that of the 996.1 in order to allow the glass rear window to lie flat.

If that 2000 has a 996.2 top, I'd guess that someone figured out how to put a 996.2 frame mechanism on a 996.1 car. That said, are you sure that's a glass window? Maybe it's just the light, but from that pic it looks like plastic to me.

LarsCarrera

Yeah...it does to me as well.but, I've not seen a "plastic" window that big on a 996. My original plastic window was about half that size. The car pictured is a salvage so, perhaps just dirty!?! I'm working on a video to post on YouTube and link from here so members can actually see and hear what's going on. I try to do my own troubleshooting and as much wrench work as I can as the nearest Dealer is 165 miles away. Local (65-80 miles) "foreign" mechs. just don't get it.

KoB

Could be the angle the picture was taken at, or maybe you're replacing an aftermarket top? My top is original, and the window could be the same size as the one in your pic ... the distance between the edge of the window and the seam of the top looks about the same: