My 99 Caddy Deville periodically shoots out black material when the AC/ Heater vent blower is on. I suspect it is old insulation breaking loose, but some of it smears on our clothes when you try to pick it off. What can be
done to remedy this problem. Thanks in advance for your help. LMa1939

 

same problem with my 1996 seville sls....i doubt there is an easy solution....probably the foam around the venting....good luck...it is annoying

 

i replaced my blower motor yesterday and discovered where the black stuff/foam was coming from...it was all over the inside of my old blower motor. guy at parts counter (cadillac dealer) said this is common on older caddys...hope this helps.