Recently, the check engine light came on in my 1999 Ford Ranger. I also noticed that the temp gauge just doesn't move up at all. Around the same time, I noticed my heat isn't working. I'm kind of hoping this is all related so it's one fix instead of several fixes. Could any one offer any help on this issue?
P.S. I'm not really mechanically savvy, but I have replaced a few parts myself so I'm not a totally inept. But if you could kind of dumb it down for me it would be greatly appreciated.

 

Heat isn't working????
So fan doesn't work?
Fan works but air is not as hot as before?

Fan works but Air is freezing cold?


Have you opened the radiator cap before starting cold engine?
Was it full to the top, it should be.

There is a Overflow tank for the radiator, is it filled to the COLD line, when engine is cold?

Leave hood open put rad cap back on
Start engine
Feel upper radiator hose by radiator
Let engine idle for 3 minutes
feel upper hose again, is it getting warmer?

If it is that is wrong, radiator is for "extra heat", there a device called a thermostat that blocks flow to the radiator until coolant in the engine gets up to 190degrees.
If upper hose is warming up then thermostat is stuck open, so engine can never heat up on a cold day.
Ford temp gauge has 210deg as the center, after 8 to 10 minutes of driving the temp on gauge should be above 1/4 and below 1/2.

Thermostat replacement isn't hard and the part isn't expensive, use 192deg thermostat, NOT 160 or 180deg