I have a 1980 toyota 4x4 that I switched the motor out and put the same 22R motor in but out of a 1983 into my 1980 truck. Since the swap, I have no heat but the fan works so it blows out cold. I have some overheating problems but no leaks are appearing. I replaced the thermostat and the water pump. Any ideas what it could be? Could it be the radiator or the hoses? My 1980 motor only had 1 hose for the heater and the 1983 motor had 2 hoses to the heater. I just t-d them together could that be a problem?

 

Did you properly bleed the system....by leaving the radiator cap off and turning the heat on in the truck and continually filling the radiator until no air bubbles are coming out. If you have air trapped in the system, the coolant will not flow correctly, thus having no heat in the driver's compartment, and overheating. Just a thought

 

your heat core could be pluged that happened with my 86 pickup and I replaced it and heat so hot that I roll down my windows.

 

Heater core is probably plugged. Besides replacing it, remove both coolant hoses leading to it, grab the garden hose with a tapered nozzle, and forward/back flush it until the water runs clear.


The pretty much narrows it down to either the fan clutch and/or radiator.

 

Heater core needs an inlet and outlet line to allow the hot coolant from the engine to flow through it. When you say to T'd the lines together, how did you do that? On my '85, inlet hose is off the heater valve at the upper left corner and the outlet hose is about in the center of the picture below:

 

I'm having problems with my 83 pickup, the heater doesn't work the fan spear even kick on.. Any advice?