I work for a Mechanical/Electrical Engineering firm in the US. We use AutoCad 2005. Is there any way to convert English to French text using this version? If not, does anyone know where to find French autocad symbols related to mechanical engineering?

You can try the internal command AMLANGCONV - see http://www.cadforum.cz/cadforum/qaID.asp?tip=5961 (in Czech). Or you can use TRANS utility.