Madrid airport terminals
 

We will be flying in from Morocco to terminal 4S at Madrid airport and will be leaving 1.5 hours later from terminal 4. Will there likely be enough time to go through customs/ passport etc and still go through the underground passageway between terminals. We will have no checked baggage. Will we have time to make our next flight? thanks!

Go by the amount of time your airline suggests you should allow. Usually it is more than 2 hours.

If you already have the tickets I guess it will have to be. Are they on the same airline? if so, do not worry.

One suggestion is to always take the elevators instead of the long two-story escalators.

Under normal circumstances I think you should be fine.

It will be tight! You will have to go through passport control upon arrival and then up to the departures area. You may not be able to make your flight unless you're flying on one ticket. If now flying on one ticket, you have to check in and get your boarding pass. Depending on where you're flying to, getting to the gate can take anywhere from 20 to 30 minutes after clearing security. T4 is a very large terminal.