Heater blowing luke warm heat

[Thatold350]

Heater blowing Luke warm
Last winter when I got the truck 1988 k2500 I replaced the heater core and flushed and back flushed the system numerous times and the heat would stay lukewarm well winter came quick and still have the problem. I checked the heater core both inlet and outlet tubes to warm to touch. Truck does have ac but doesn’t work, seems like every actuator clicks while being used. Does anyone know how to diagnose the problem

 

[Peaches93Z71]

Heater blowing Luke warm
Last winter when I got the truck 1988 k2500 I replaced the heater core and flushed and back flushed the system numerous times and the heat would stay lukewarm well winter came quick and still have the problem. I checked the heater core both inlet and outlet tubes to warm to touch. Truck does have ac but doesn’t work, seems like every actuator clicks while being used. Does anyone know how to diagnose the problem

Check your thermostat. You may not be getting full coolant flow if it's stuck. The coolant is heating up in the engine but not flowing completely once warmed up. The heater hoses aught to be hot with the heater on full blast and the engine at full running temp. Could be that simple.

 

[rzr6-4]

Check your thermostat. You may not be getting full coolant flow if it's stuck. The coolant is heating up in the engine but not flowing completely once warmed up. The heater hoses aught to be hot with the heater on full blast and the engine at full running temp. Could be that simple.

I second that. My heater was enough to defrost the windshield but 20min down the road I was still uncomfortably cold. New thermostat and I'm sweating by the 10 minute mark.

Easy and cheap to replace, so you're not out much if it doesn't work.

 

[Jimmy D]

Heater blowing Luke warm
Last winter when I got the truck 1988 k2500 I replaced the heater core and flushed and back flushed the system numerous times and the heat would stay lukewarm well winter came quick and still have the problem. I checked the heater core both inlet and outlet tubes to warm to touch. Truck does have ac but doesn’t work, seems like every actuator clicks while being used. Does anyone know how to diagnose the problem

If your heater core inlet and outlets are too warm to touch hot coolant is getting there. You may have a temp door actuator out of wack inside the dash. Proper operating actuators should not click.

 

[Thatold350]

how do I check for those and get to them?