[E30325]

So as the title says, I have two separate issues with my trucks heat/HVAC.

First, it randomly comes and goes, but more often than not my blower fan only works on high, nothing on any other setting. From what I understand there is a relay in the dash that goes bad and only lets it run on high, it seems weird to me that it would sometimes still work on other settings though. Any ideas?

Second, the heat in general just kinda sucks, turned all the way up it’s warm, but not hot, you can easily hold your hand on a vent and it’s not uncomfortably warm. Is this normal?
Keep in mind it’s winter in Montana and outside temps are often 10 degrees or less, but motor is at operating temp.
Would a winter front grill cover help heat or just help the motor hit operating temp faster? Thanks!

 

[Ox1]

I keep a pc of cardboard between the rad and the condenser in the winter. May want to pop a cpl holes near the top and use a cpl zip ties to the wiring harness running accrost the top of the rad. But that mostly only helps for idling. I think that the stat seems to default to enough flow that idle does not make more heat than the rad will cool at that flow. And we sleep in the truck sometimes in the bush, so that is a problem that I am aware of.

Also, the flapper doors in the ducting are for Schidt! You may not be getting a full closure on your doors. That is kind'a a big job. It's a weekender, not an evening job. There are a cpl places to fetch new doors, but I don't remember anymore, but I'm sure that a search for that here will produce those results.

I know that I followed someone else's documentary on the subject when I did mine. Not sure if it was on here, or another site, or youtube, or ??? But that is helpfull for sure. Especially knowing where all the dash keepers are and how to address them. I think that I must have not gotten a cpl of light bulbs put back right - as my heat/AC controls are dark, but I'm not opening it back up for just that!

.

 

[MoparProud]

A winter cover will not get you adequate heat.

I’ve been fighting a non working heater in my ‘03 for years and it really sucks. Are your doors moving, ie does it change settings when you turn the knobs? If so, it’s not doors (unless maybe blend door…). I’ve put in aluminum doors and, I mean it works minus heat.

Start with simple stuff like thermostat. When it’s cold it can hide a thermostat issue

 

[krs]

So as the title says, I have two separate issues with my trucks heat/HVAC.

First, it randomly comes and goes, but more often than not my blower fan only works on high, nothing on any other setting. From what I understand there is a relay in the dash that goes bad and only lets it run on high, it seems weird to me that it would sometimes still work on other settings though. Any ideas?

Second, the heat in general just kinda sucks, turned all the way up it’s warm, but not hot, you can easily hold your hand on a vent and it’s not uncomfortably warm. Is this normal?
Keep in mind it’s winter in Montana and outside temps are often 10 degrees or less, but motor is at operating temp.
Would a winter front grill cover help heat or just help the motor hit operating temp faster? Thanks!

You will be happiest with the Mopar winter front for your truck. It is worth the money.

Secondly how old is your thermostat? I usually end up replacing mine every 3 to 4 years and only with a Cummins one. The parts store ones are a crap shoot and have issues that can damage your engine.

The blower fan resistor in your dash beside your blower fan wear out. It is very easy to replace. Only replace with Mopar one. I have had new parts store ones fail in less than 4 months. Most common issue with fan speed.

Alfaobd can calibrate your blend doors in your HVAC system and detect a failing actuator. If you open up the dash I recommend the Blend Doors USA and replace both heater core and the AC evaporator so you dontnhave to go in there again for a very long time.

 

[E30325]

I should clarify, all positions for the vents work fine, and the fan puts out a good amount of air so it’s not a blend door issue, it’s just that the air from the heater doesn’t come out super hot.

I think the previous owner did a water pump and thermostat on it but it’s anybodies guess how many miles ago that was. Motor never runs hot or anything weird though

 

[dozermand65]

My 05 was the same way, went in and found evap was pretty dirty and heater core was too, replaced both, the insides of the heater cores in the little tubes get gunked up, do the heater core and the evap and you'll be a lot happier

 

[Ox1]

I think that I replaced the heater core when I did the doors.
I imagine that is in the door replacement threads.

You say that it is NOT a door.
How doo you know that the blend door is not stuck to cool, or even not even on the rail anymore.
It's not the actuators that is bad. I think that I had at least one door broken right off the rail.

Mine is an 06 and I did that job prolly at least 4 yrs ago.

 

[E30325]

If it was stuck to cool wouldn’t I not get heat at all? Heat and all blower controls work, the heat just isn’t as hot as I would think it would be

 

[Ox1]

Well, as you dial in your heat setting, you are just finding a sweet spot between all hot and all cold eh? Somehow you are likely stuck in the middle.

But there are [little] motors that run that stuff these days. B/c of course - we are in an age where we are beyond sliding a cable to adjust it, or having a lever on the floor to engage 4wd or Low Lock. So, the blend motor could have failed, or the cabling to it, or the switch that tells it to move, or ...

IDK if you can git to the blend motor or not (I think that you might be able to?) then maybe you can take it off and turn the dial, and see if the motor changes position. And you may be able to manually position the door to git some heat too - if the motor isn't working.

If you follow through one of the threads with pics and all about changing out the HVAC doors, you will be able to visualize what and where you are looking for.

.