My heat sucks

So I know it sounds stupid and I hate to admit it, but in the 80's I had a 74 Dart Sport that I couldn't get any heat out of. I suffered almost the entire winter scraping the ice off of the INSIDE of the windshield. I tried flushing the system and blocking part of the radiator but still couldn't get any real heat. Then while working on my radio under the dash I found it. The cable from the temperature adjustment had come loose. I put it back on and wa La Heat!!!! Just something I would check.