After installing a replacement radio in my 94 Jetta the all of the speakers
do not work. The speakers were working prior to the install. The radio
comes on but no sound. Are the speakers tied in to an amp.

Test them w/o the amp first. Your posting is too vague to really know what you're talking about. What kind of radio? What type of amp? (as in subs or all four speakers?) We need these details to help you better.