1988 Chevrolet S 10 Heater Will Blow Hot Air Slightly Warm Thats Changed

With the engine at full operating temp, locate the 2 heater hoses where they go into the firewall and feel them to see if they are both hot to the touch. If they are both hot, the heat in that vehicle is controlled by a blend door that regulates heated air flow. it is operated by an electric motor/actuator. The problem can be that the actuator is stripped or inoperative or the door itself could be damaged. This is what needs to be determined by examining the actuator and see if it is responding to heat change commands or not.

Where is the actuator located and is it a big job i have done a majority of the work myself so just wanting to save money

One step at a time. Do the other checks and we'll go from there.

I just had the truck up to temp and the one going to the engine from the heater core is warm but the one going from the rad to the heater core is cold

That's indicating a plugged up heater core, probably from old dexcool getting sludged up.

You can remove the heater hoses and try to flush the core with water pressure from a garden hose but if the engine is dirty too, it will get plugged up again quickly.

I tried to flush it and it seemed to go warm but then cold again how do i clean everything out would it help if i drain all the rad fluid and rinse them out then rinse the heater core out again and refill it ??

It's going to take some chemicals and professional flushing to get the rest of the cooling system clean and even then it may not come clean because it's just too crusty.

Hmm nnow what to do haha