Still haven't got a clue what you're talking about [8)]
Is it th elittle tube on the RH bottom of this heater?
As far as i know there where only two types of heater used on the TR7;
1. Non A/C heater which had the water drain incorporated in the plastic moulding of the fresh air inlet chamber;
2. A/C heater which has a steel drain tube welded to the steel fresh air inlet chamber;
Which heater do you have in your car ?
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<font color="blue"><i>1980 TR7 DHC (my first car, currently being restored)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="2"><font color="red">My Weblog</font id="red"></font id="size2"></b></u>[/url]</b></i></center>