We are in the process of converting our cd account #s from two seperate # to one all inclusive number. Does the bank need to send out new signature cards to show the new account number (that has both numbers now as one number?

Any thoughts would be appreciated...

No. Just have a customer-friendly system in place as calls are received, etc. If you do not, you'll scare people!

I would think if the old signature cards had a number that could be associated to the new account number with no room for error, you will be fine.
For example: the old way had 12345 on the signature card with a "back room" additional number of 123 associated with that cd - the new way has a number of 12312345 on the account and the last five digits aren't repeated with any onther account.

Thanks for your comments...I appreciate them...Javier