Cold Ride

[MrBlue]

Happy Thanksgiving to All,
Anyway, a couple of weeks ago I took the truck to pick up some shelving that the local box store did not have. No big deal, just drive 30-minutes to the store that had stock. Temp outside was 40-ish degrees. Turn on the heater and start driving. After a couple of miles on the highway, and the heater fan on high, it starts to cool off in the truck. Not bad, but as I recall from way back when, that this was not normal. I could feel the heat coming from the vents, NON AC cab.
So, is this normal?
The heater core and fan motor are new. Yes, the hoses are connected correctly.
Thanks for stopping by.

[orangek5]

coolant level low?

[marvgarr68]

Low coolant will do that also stuck open thermostat. What was the temp on the gauge? What deg thermostat do you have? I know if its a 160 it does not get very warm in the cold.

[Stocker]

With the engine warmed up and idling, and the heater on, are the radiator hoses hot to the touch? And are the heater hoses hot to the touch? Do you have a good 190* or 195* thermostat?

[special-K]

I always run 180 deg. thermostats and get enough heat that I never use an ice scraper and never where a jacket when driving. I set the levers in the center and don't use the fan. First check coolant level. Usually when that's low you get off & on heat. Next check the the hoses for heat and the upper radiator hose for expansion. If they're not hot check the thermostat. The next thing would be poor flow in radiator and/or heater core. Another possibility would be the levers aren't activating (broken/loose cable or other related problem)

[PanelDeland]

I haven't looked at the current replacement heater cores.I have a Dodge Dakota and a 2000 Blazer.Both have smaller diameter tubes in the heater cores than was common when these trucks were new.Both have to have the heater core flushed about every 2- years.The coolant's anti leak properties tend to clog these smaller tubes.
I just use a garden hose and flush clear water thru the core each direction a couple times until I get good flow(you can see the difference) then reconnect and the heat comes back.

[MrBlue]

Gents,
Thanks for the responses.
The coolant level is/was fine as is the temperature of the heater hoses.
Coolant temperature was 200-degrees.
I am wondering if the heater fan is pushing enough air? Or that these cabs have no insulation and that is contributing to the coolness of the ride when it is cold outside.

[Stocker]

Originally Posted by MrBlue

Or that these cabs have no insulation and that is contributing to the coolness of the ride when it is cold outside.

I wouldn't think so. These heaters pour out an awful lot of heat and I've never had any problem staying warm inside.

[special-K]

These trucks have always been some of the warmest vehicles I've driven. Definitely something wrong on yours. Either the heater core is restricted or your controls aren't activating what they are supposed to. In other words,your heat isn't being turned on. I only use the fan to defrost/deice before driving or when driving with the window open when it's cold out. Ok,or of I need more defroster. These trucks' heat will have you stripping to naked and sweating with the fan and heat on high for very long. Even if it was the fan,can you hear the fan blow? If you can hear it,it's blowing. I don't know how long you've owned you truck or if it has spent any length of tome sitting,but mice can get in there and block air passages and/or keep flappers open/closed. If you're making good heat and it's being blocked,you could end up with a parts meltdown,or worse,if not remedied

[Stocker]

^ Good point, but in his initial post he said the heater core & fan motor are new, so I figured the mice have been removed.

One other thing to check -- is the fresh air vent in the kick panel open? That would let in a lot of cold air....

[special-K]

Oh yeah,I guess the mice could be within the heater itself (under dash) still. I've found them nested where the diverter was stuck shut. If you hear no fan,check the fuse and connections.

[bigmac73]

i would check the heater resistor, maybe the fan motor is not getting enough juice to turn fast enough??

[Mister-B]

Originally Posted by Stocker

I wouldn't think so. These heaters pour out an awful lot of heat and I've never had any problem staying warm inside.

Yes. Plus with a truck, you're heating up a small enclosed cab. You don't have a back seat and rear cargo area to heat.

[MashTheGas 72]

I just went through this and found out my flapper in my heater box was stuck. I freed it up and instantly the heat started working and I had to roll the windows down it was so hot. I reached under the dash and worked the flapper Control with my hand until it freed up. Mister-B was the one who told me to try this. Hope this helps.