Not much Heat, Help

[twoskies]

Evening All

1972 c10 , 1979 chevy 350,new 4 core aluminum radiator, replaced heater core when working on truck, drove all summer, temp gauge stayed lower side of left side, now its getting colder, truck puts out very lukewarm heat, heater hose's , 3/4 hose runs from top of water pump to top of heater core, lower 5/8 hose runs from manifold by thermostat housing to bottom of heater core, changed thermostat out to 180, used heat gun and hoses and radiator is getting hot to touch, about 90 to 100 on heater hoses, radiator hoses are a bit hotter 135

Thanks , any help appreciated

[geezer#99]

Put a 195 thermostat in it.
And maybe look for a winter front to cover the grill.

[Andy4639]

Have you taken the lower heater stuff a part inside the truck and cleaned it out good? Are your side vents closed? Make sure the cables are adjusted right and are operating the flapper door inside the box. Is the element working inside the lower box?

[Stocker]

Maybe a plugged (or partially plugged) heater core?

[twoskies]

Thanks for the replies

not an ac truck


yes, vents are closed

goofy question, how do i check the blend doors, i did unhook the defrost/floor cable and just switch by hand, down for floor, up for defrost

do i have to take box apart ?

also, blower motor has 1 speed , probably just motor, 1 thing i didn't change

Thanks

[Andy4639]

Take it a part where the screws are and check inside to see if there any signs of rodents. They love building their nest up inside these. When you have it a part check the flapper by hand.
Just my opinion. I run the hose that comes off the pump to the lower fitting of the heater core and then back to intake. This makes sure there is no air in the system.

[twoskies]

ok
just took inside box apart, no rodents, lol, flapper was not working quite right, i can adjust tomorrow, the element inside on top of the inside box, how do i know its working right, also would the element not working right mess with the blower speed,more than likely done tonite, gotta work tomorrow

Thanks

[LockDoc]

Originally Posted by twoskies

ok
just took inside box apart, no rodents, lol, flapper was not working quite right, i can adjust tomorrow, the element inside on top of the inside box, how do i know its working right, also would the element not working right mess with the blower speed,more than likely done tonite, gotta work tomorrow

Thanks

If the coils are not broken or touching each other on the resistor (element) and the connections are tight, it's probably OK. If I remember correctly the low and medium blower speeds go through the resistor and the high speed bypasses it. The switch could be bad. It's on the side of the heater control unit under the dash. If you follow the wires from the resistor they will go to the switch. You can test the switch with a multi meter.

If the door on the fresh air side of the heater core is not opening you will not get any heat. Follow the long cable down under the heater box on the right side, and remove the black plastic oval plug. Using a flashlight make sure the cable end is on the pin of the door and the door is opening and closing when you move the control arm on the heater control panel.....

LockDoc

[Andy4639]

Originally Posted by LockDoc

Are the heater hoses getting hot to the touch? There should be hot water flowing through the heater core all the time.

If the coils are not broken or touching each other on the resistor (element) and the connections are tight, it's probably OK. If I remember correctly the low and medium blower speeds go through the resistor and the high speed bypasses it. The switch could be bad. It's on the side of the heater control unit under the dash. If you follow the wires from the resistor they will go to the switch. You can test the switch with a multi meter.

LockDoc

That's how I remember it also Doc. Most times it's the fan switch is bad.

You can take the fan switch a part and clean the contacts and put it back together and most times it will be fine. Just remember which way the slid goes when you take it a part.
I fixed mine in the ramp truck right after I got it. That was 3 years ago.

[Greasey Harley]

I usually cover part of my radiator with one of those high-tech corrugated radiator covers.

also as previously stated, winter thermostat 195 or 200/205 degree