Hi and welcome to JA. Ray here to help you today.
You can order the deceased's persons prior tax returns.This would show any accounts that bear interest or have activity.This should be a good start here to locate such accounts.You are also allowed to order the deceased's credit report again it would show any assets at time of death at least.
Finally you can take this up with the judge.Executor can be removed by the court if they have failed to communicate with you .This is a breach of fiduciary duties.You may want to start here gathering information and then consider trying to remove the co executor for failure to communicate here with you through probate court.
You have rights here to do all of this.
You can order copies of prior tax returns here
Credit report here
The three nationwide credit reporting companies have set up a central website, a toll-free telephone number, and a mailing address through which you can order your free annual report.
To order, visit annualcreditreport.com, call 1-***-***-****. Or complete the Annual Credit Report Request Form and mail it to: ***** ***** Report Request Service, P.O. Box 105281, Atlanta, GA###-##-####/p>
You will need letters testamentary from where you were appointed by the court.You may consider your own lawye here for removal if you decide to pursue this.
I appreciate the chance to help you today.I wish you the best here.