[vaichus]

i just changed out my thermostat because I had no heat. Thought I would start there but it did nothing. Temp gauge is working fine. No leaks on my passenger side floor. I have a chk eng lite that went on but since my truck is a 95 the auto parts store can't diagnose anything older than a 96. Anyway, I was told a few things; heater core, actuator door mechanism, and a relay under the passenger side dash. Is there a way to trouble shoot my problem before taking apart my dashboard and start replacing each of these? Oh, I should also mention this past summer I flushed the radiator system for the first time in a real long time. Just thought I'd mention it. Thanks for whatever help comes my way.

 

[GTyankee]

I would look at the YouTube videos
Start with the HEATERTREATER vids
also look at the the vids that show how to clear out the heater core

 

[panhead]

You should be able to the 3 turns (key on, key off x3). The check engine will blink so many times. Search the site for the proper procedure. Does the blower fan work? Do you hear the actuator door working?

 

[Okiespaniels]

If your heater hoses are hot, then your heater isn't plugged. If the inbound is but the outbound hose is cold you've got a heater core issue.
I would guess your blend door system isn't functioning, or you've got a vacum leak or leakdown if your vacum filter/check valve is bad. That valve is in the engine compartment on the back pass side, usually by the valve cover with a mess of other lines.
Try googling dodge ram blend door.

 

[Warlock III]

I would check the thermal relay. It's easy to get to and located under the passenger's side of the dash. It's held in with 2-7mm screws and has a plug with 4/5 wires in it.