As many of you know, the '90 models have quite a number of little differences between the '91+ model years. One of these is cruise control switch functionality – on '91+ cars the cruise control switch is a switch to ground, however on the '90 cars it is a switched 12v line. This means that the clutch-cut wire which was included with your ECMLink package will not work on the cruise-control switch (it DOES work correctly if installed on the starter switch), and you will need to do a little more work if you want to use NLTS on a '90 DSM using the cruise switch (the one activated when your foot is completely off the pedal).
Note: The ECU diagram here http://www.dsmlink.com/images/forums/1GECUPinout.pdf shows the wire into the ecu as black w/yellow, although at least one person has reported that their 90 talon has black wire with red dots instead.
VIDEO: One of our customers, Robert Baxley, has provided a how-to video on this.
The simplest method on a '90 DSM is to cut the wires going to the cruise clutch switch and rewire them to match the more common 91+ configuration. The ECU/ECMLink just wants to see a switch to ground on the ECU input. So cut both wires going to the clutch switch. Then rewire one side to chassis ground and the other side to the ECU input. Check all this with a meter, of course, but once that's done, you should be set. The one drawback to this method is that you will lose cruise control cut out with clutch pedal activation. For most people, that's not a big deal because they either no longer have cruise installed or they don't use that particular feature anyway.
This method is a bit of work. It's provided here because it does technically allow you to keep cruise cut operation with clutch pedal activation if you happen to still have cruise control installed. But it's probably more work than it's worth.