Access refers to an increase, outburst, or the ability to get something.
- Their winnings at the casino gave them an access of wealth.
 - What started as a small dispute turned into an access of rage.
 - We give certain users access to the secure web site.
 
Excess refers to an overindulgence or surplus.
- Betty has an excess of property she would like to sell.
 - At the picnic, a few employees ate to excess.