Having trouble creating a series in graph that is dependent on tab

[Hairball]

I am trying to make a stacked bar graph. The total amount for the bar is the
summation of the same field from 3 different tables. How do i group this so i
can see how much each table contributes to the total amount of the bar. I
need the series to be, Math Data, People, and IssuesHere is my SQL statement
so far. This gets the sum right, bu tonly displays one color.

SELECT Null,Sum([Issues]![SMTChassis]+[Math
Data]![SMTChassis]+[People]![SMTChas]) AS [Chassis],
Sum([Issues]![SMTElectrical]+[Math Data]![SMTElectrical]+[People]![SMTElec])
AS [Electrical], Sum([Issues]![SMTExterior]+[Math
Data]![SMTExterior]+[People]![SMTExt]) AS
[Exterior],Sum([Issues]![SMTHVAC]+[Math
Data]![SMTHVAC]+[People]![SMTHvaccum]) AS [HVAC],Sum(
[Issues]![SMTInterior]+[Math Data]![SMTInterior]+[People]![SMTInt]) AS
[Interior],Sum([Issues]![SMTPowertrain]+[Math
Data]![SMTPowertrain]+[People]![SMTPower]) AS
[Powertrain],Sum([Issues]![SMTSTR]+[Math Data]![SMTSTR]+[People]![SMTStr]) AS
[STR&CLO] FROM [SMT Performance Maker];


Thanks for Any help you can offer.