When i first got my 85 the heat worked well. but for some reason over the years it doesnt work anymore. it just blows just enough heat out to unfog the windows and if it its icy out side forget driving it. I dont drive it in the ice but i would like to take it out on the clean and cool days this winter. The things i have done that could have messed this up would, i got rid of the air conditioner equipment i plugged all my lines. IS there a way i can rig this thing up so it will be hot again?

 

does the engine run colder too?

 

While the car is running at operating temperature, check the status of BOTH of your heater core hoses.

Are BOTH hot?
is ONE hot and ONE cold?
Are BOTH cold?

LUK!

 

Okay both heat hoses are hot. Ive made sure that the blend door is turned to the heat position by disconnecting the cable and pushing in by and but still the same problem. I did get the heater core replaced awhile back and haven't had good heat since. is there something else that could be wrong like a vaccum line not hooked up that could cause this? My engine temps stay between 185-200.

 

is it low on coolant?

 

No man ive checked everything new thermostat. too

 

Try to backflush the heater core. Remove hoses at heater core and take garden hose and flush water through the core the opposite direction of normal flow. Did a friends Ranger last week and the heater started working. Bubba

 

does it only give heat when on highway speeds?

maybe your blower motor?

 

What temperature thermostat are you using?

 

I had the same problem
mine had sludge filling the heater core up
this fixed mine.