Gas dryer wont start, light is very dim inside drum

Was replacing idler wheel and belt. Went to start new problem. it wont start, timer ticks interior drum light is very dim but lights bright when you push timer to start. Checked door switch, seems to be okay but unsure how it really works with 3 terminals with one wire on terminal 1 and strap between 2 and 3. Please help if you can.