One pivot chart from two spreadsheets

I have a large spreadsheet that will soon exceed the row limit in Excel. I am going to split it into two sheets. I have one pivot table (one Page item, Four row items and four data items) that is currently produced from the spreadsheet. I need the existing pivot table (or a new one) to access data from both sheets. I tried the 'consolidate' option, but it doesn't seem to do anything like what I need. Am I going about this in the wrong way?