Convertible top mystery, can't find problem Options

[davewuyts]

hello everyone

I've been trying to sort out my '95 Celica convertible top which is not working properly. I've read and tried some fixes on other posts but am stumped.

The roof has been working fine for the last two years, going up and down without complaint. But suddenly it would only open half way: the rest only happens if you give it a little help. And closing it is fine except it won't do the first bit: once it's nearly vertical it will work. Neither motor ever sounds like it's under strain or anything is slipping or missing.

I've checked the roof mechanism in case something is jamming or sticking, but all is fine. I've checked the back window in case it's shifted and is jamming on the seat back. It isn't. I took the motors out today (leaving them connected) to see if they were both turning the cog consistently. They are. Both revolve at what seems to be the proper speed, the note from the motors sounds the same as it always does.

So I'm stuck. Can the motors just lose a bit of power? If so they both sound identical to before and to each other. Otherwise what can I check?
Ideas welcome!
Dave