Chevrolet Repair: Heater will not work 88 Chevy Cheyenne C1500, changing a thermostat, gasket material

Question
I am trying to figure out why my heater will not work. The air conditioning works great, all of the gauges, with the exceptions of the gas and speedometer, work. It is very cold, and I will have to try to fix it myself, as I can not afford to hire someone. Please help!

Answer
Hi Melissa,

I found this question in the question pool.  This is the trash can for questions that the expert orginally asked doesnt answer.  At this point anyone can answer it.  I hope I can help.

First thing I am going to say is you should email me at cschevy@yahoo.com if you have any questions or need further advice.  

Does your heater selector work?  Can you tell if the door that directs heat into the truck is opening or closing?  I am guessing it does work.

Low radiator level could also produce no heat. Check to see if you are full.

The heater is controlled by a thermostat.  That is a door in the path of the cooling system that is opened and closed by the engine, to adjust the temperature of the engine.  When you have no heat and the motor is not overheating, this usually means the thermostat is stuck open.  This does not allow the motor to get hot enough to make heat.  

Changing a thermostat on a Chevy is easy and under $20.  Follow the top hose from the radiator back to the motor.  Where that attaches to the motor is the thermostat housing.  Usually 2 bolts here hold the housing down.  Usually 14mm or 9/16".  Be careful taking these bolts out because they could break if old and rotted.  This will seriously complicate things.  

This housing is called a gooseneck.  It looks like a ball with a spot for a hose to attach to.  YOu take the two bolts out and use a pry tools, or screw driver and pry up under the hose area.  This will pop up.  Take out the thermostat with a pair of pliers.  Should come out easily.  Take a wire brush and scraper and clean the gasket material off the gooseneck and where the part bolts to the motor.  Now drop the new thermostat in place.  Put the new gasket in place.  Use no sealant.  Put the bolts back in and tighten them snug.  Do not over tighten.  Put a little antifreeze into the radiator to top off the level and you are done.  

Email me if you are confused or need more instruction.

C J S