There are several places you can work with I think MM&G. For one, you do have the extra Green wires over in the passenger corner of the engine compartment still, correct? I would think any of them would work, but the one double-Green in the plastic connector might be the best.
But you should still test that they're hot in START too. On a stock harness, there are only two circuits that are hot in both RUN and START, but with the Centech there may be more, as the ignition switch feeds the fuse box differently than the stock one does.
Of course, when in doubt you can tie into the ignition coil and electronic ignition feeds.
Also over on the passenger side, they should be the two Blue wires (one's a darker Blue if I remember)
Start there and do some testing to make sure whatever wire you choose is hot in START too.
If the wires mentioned do not have START power, I would double check the back of the ignition switch under the dash to make sure it's still functioning properly. Is it a new switch with the harness, or your old (and perhaps original) one?
Paul