Cabin Fan / Heater Problem

[dieselpower]

The fan in my 05 f350 only works on high or off...and when I was driving up to the snow (got down to probably 20) a few weeks ago I noticed that with the heater set on 90 and the fan wide open, it was hardly keeping it warm. Bout had to wear my coat inside. It seemed like if I switched between defrost and floor, etc., the heat would come on for a bit and then fade away. Any thoughts? Fan is probably a resistor fuse, and the heater problem might be a vacuum issue?

Thanks!!

 

[Lassie]

Vaccuum pump/leak, thermostat, or...........................................................................:shocked:
dare I say it, heater core vapor locking due to compression gases

 

[Dittmerdiesel]

This very thing happened to me a few months ago. I had the smell of coolant as well. Coolant was a leaking heater core, the core was plugged as well which caused the heater to go in and out. My fan did the same as well and it turned out to be the fuse. Unfortunately, the heat only lasted for a week or so when I found out the head gaskets were blown also. So my guess would be the heater core and/or blown gaskets.

 

[Atsah]

As far as the fan speed goes, when your resistor is gone your blower defaults to high only.. As far as not getting warm/hot air, could be a leak of some sort or the core is gone..

 

[dieselpower]

Hi guys needing some help again...

I finally got around to changing the resistor, but something is not right plug wise. I have attached a few pics of the resistor I got (which is right according to parts store), and pics of the old resistor(?). As you can see, the plug is different, and the whole resistor setup is different. Any thoughts? Or am I missing something?

New resistor:

Old resistor setup:

Plug (not same as resistor)

It looks like someone may have put a different fan/resistor setup in, but maybe I have the wrong resistor although that seems unlikely. It looks just like one that is shown in 1a autoparts replacement video 99-07.

 

[Atsah]

That looks like the right one that you bought.. I have never seen the other one shown...

 

[dieselpower]

That looks like the right one that you bought.. I have never seen the other one shown...

Hmmm someone must have wired in their a different plug an resistor setup. That's odd.

 

[Atsah]

Hmmm someone must have wired in their a different plug an resistor setup. That's odd.

Are you saying you took what's in the second picture from here?

 

[dieselpower]

Are you saying you took what's in the second picture from here?

Yes. Mine looked nothing like that. The plug came into the bottom end instead of front like yours.

And as you can see by that pic, their is like a weird motherboard there or something. Doesnt look like a resistor setup really although it must be.

 

[suprdzlduty]

Do you have the automatic climate control? I would say you do since you said you had it set on 90...those take a different resistor.

 

[Atsah]

I just did a little reading... The one you have is for automatic climate control, part # 6C34-19E624-AA.. That is what you need.. I have never seen the unit with the heatsink but I have had all manual heat and ac trucks..

 

[Lethalthreat7.3]

The automatic climate control is solid state. The one you purchased are the standard blower resistor.
As far as heat, then cold. There is a blending door actuator located behind the glovebox to the left. Try unplugging it, cleaning the terminals and reinstalling it.

 

[dieselpower]

Thanks a lot guys, that explains it. So one last question...that is for sure not the problem and I can put it back together? I'll look into what you mentioned about blowing that other thing off and see if that helps.

 

[Atsah]

Thanks a lot guys, that explains it. So one last question...that is for sure not the problem and I can put it back together? I'll look into what you mentioned about blowing that other thing off and see if that helps.

It sounds like you still need to replace the resistor but you need to get the right one.. I agree with the above concerning the blend door, when your heat changes from say floor to defrost by itself, the doors are moving when they should't be..