heater not working

[bigchevyc30]

ok so i know its summer the best time of year for heating the inside of a truck jkjk. but my mom is wanting me to see why my heat dont work in my truck and im needing to know what i need to look at on how to get it working again. i have a 1980 c-30 had a 454 in it as youve read from my other posts before. if you can please reply back to me as fast as you guys can i ought to get some help from you guys since this is a chevy truck sight. thanks in advance

[zieg85]

The first place is to check the temps of the heater hoses.  They should be about the same temperature in and out.  If the temp going back is a lot cooler the heater core has a blockage.

[Blazin]

X2 on the hoses. So does the blower work? Is it blowing hot air and just not much of it? Is it blowing cold air? Doe the temp., and postion controls work free? Do they actually open the doors in the system that they are supposed to?

[bigchevyc30]

motor does not work my truck doesnt have ac as people before us took it out the switches are free but have a good bit of resistance to them. idk if the doors open where would i be able to check the door that i know of the hoses and core are fineplenty of heat from it

[zieg85]

OK, if I read correctly the PO removed the AC compressor???  Assuming everything else is in tact as a factory AC cab the COLD-HOT bottom lever is cable operated so you have to determine if the cable is operating the door to open and close off the heat.  The upper lever that switches from defrost to vent to floor is vacuum operated.  There should be a vacuum line coming through the firewall that hooks to a round black plastic ball looking vacuum reservoir hooked to engine vacuum.  If the blower motor isn't working you have to determine if the motor is bad, the resistor block or the switch.  Check the fuse first.  Let us know what you find and I am sure others will make suggestions along the way.

[bigchevyc30]

ok so far the door that is oppened by a cable it work butthe one that zeig said ran on vacume from the engine doesnot have a vacume line as onlything on the motor is for the transmission. motor i still dont know about