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-   -   Blender doors or electrical??? (http://www.ramforumz.com/showthread.php?t=117840)

mjpzr2 07-24-2012 10:02 PM

Blender doors or electrical???
 
I own a 2005 SLT with 5.7 Hemi. I am having issues with my blower fan. I almost always run it exclusively on the heater (floor) setting.
At first when it would quit running, I could jiggle the keys and the fan would turn back on. After a while, it started to blow half on the floor and half out the defroster vents when I had it on the floor setting. Eventually, I would have to try and turn the ignition key back a little to get the fan to stay running. Eventually, that quit working so I bought a new ignition module. After installing that, the blower fan would run, however I still have half floor and half defrost air flow, except that now I don't have power to any of my windows. If I reinstall the old module, I have windows but no fan.

My first thought was of the blender doors, being that the air blows out both the floor and the defrost vents. However, after switching to a new module, it seems something electrical??? Maybe it's both electrical and blender doors??? I've already removed and checked the blower fan and that is all good. I've checked the wires underneath the steering column for burn marks and got nothing. Is there anything a novice mechanic can try without the dreaded thousand dollar trip to the dealer?

Thanks

ArtNJr 07-30-2012 02:58 PM

I'm about 99% sure the system which switches the direction of the air coming from the fan (floor, defrost, etc.) is vacuum operated. There may be a vacuum line loose & even one with a pinhole leak in it will keep the system from working properly. A service manual will help you find where the lines are & how they should be routed. There's even one for the cruise control on my diesel truck & it's a bear to get to, under the driver's side battery!

starquestbd22 07-30-2012 04:16 PM

Quote:

Originally Posted by ArtNJr (Post 853279)
I'm about 99% sure the system which switches the direction of the air coming from the fan (floor, defrost, etc.) is vacuum operated. There may be a vacuum line loose & even one with a pinhole leak in it will keep the system from working properly. A service manual will help you find where the lines are & how they should be routed. There's even one for the cruise control on my diesel truck & it's a bear to get to, under the driver's side battery!

It's a good thing you left that 1%, lol. The doors on our trucks are controlled by little electronic motors rather than vacuum controlled like most vehicles.
***EDIT*** This applies to the third gen trucks....I'm not sure about the pre-2002 trucks.

This is just a guess and it may not help a lot but my guess would be that your problem is not the HVAC doors. If it were, it would likely be mode door 2 instead of the blend door. The blend door controls the mixture of hot/cold. Mode door 1 diverts air from the main face vents to the secondary part of the system. Mode door 2 controls whether the air then goes down to the floor or up to the defrost. Typical failure of the doors occurs when the plastic limit pins or the plastic doors themself break from the pressure exerted by the electronic motors. Failure of mode door 2 typical results in the door falling down completely blocking the floor vents and diverting all air from this part of the system through the defrost. This is why I do not think your issue is mode door 2 or any HVAC door for that matter. I suppose it is possible that mode door 2 has stuck in the middle and is allowing air to go both ways but I find that unlikely, especially when considered with the other electrical problems you are having.

If you wish to troubleshoot the HVAC doors you can go to youtube and search "HeaterTreater Dodge Ram". I'm not sure they even offer a vid for mode door 2 though because it is very deep in the dash and is by far the hardest door to access.

ArtNJr 08-01-2012 01:58 AM

Quote:

Originally Posted by starquestbd22 (Post 853317)
It's a good thing you left that 1%, lol. The doors on our trucks are controlled by little electronic motors rather than vacuum controlled like most vehicles.
***EDIT*** This applies to the third gen trucks....I'm not sure about the pre-2002 trucks.

That must be when the change was made -- the HVAC on my (1998.5) "2nd generation" truck is vacuum operated.

starquestbd22 08-01-2012 07:45 AM

Ahhhh, gotcha. In that case, Dodge would have probably been better off to stick with the vacuum operated system. The electronic system sure has caused a lot of headaches for Ram owners.....and cold feet too, lol.

ArtNJr 08-01-2012 09:14 AM

Vacuum is bad enough -- I can only guess @ how time-consuming it would be to take the dash apart to get to little servo motors :-(

I know why manufacturers do that though (having been a manufacturing engineer) -- the profit on new vehicles is surprisingly low & the engineers design them to go together as fast & as efficiently as possible on the assembly line -- no thought is given to servicing individual parts @ a later date. (I always said if I owned a car co. I'd make new engineers work as line mechanics in a dealership for 2 years before they would be allowed to design anything -- but the cost of the vehicles produced would be astronomical).

And since the service dept. is where the dealerships really make their $$$, the longer it takes, the better. Most charge by flat-rate manual & a good mechanic can beat it easily -- i.e., if the manual says this job takes 5 hours, the customer gets charged for 5 & the mechanic (excuse me, "technician") gets paid for 5 -- even if it only takes him an hour & 1/2. Techs learn to be good 1st, then fast & one of my good friends quit a management job in a dealership to go back to being a "line mechanic" simply because he made a lot more $$$ -- he's both good & fast & his paycheck is for a 120-hour week on average, even though he only actually works 40.

GTyankee 08-01-2012 09:40 AM

looks like you already have some good advice

i will just add, on a rainy day look at some of the YouTube videos
the 3 by heatertreater are very informative, but several others have also posted their own findings & fixes
some people have pulled the whole dash, others found a way around doing that
some were not exactly geniuses LOL

mjpzr2 08-01-2012 03:38 PM

I thank everyone for their responses. The problem that I am having is less about where the air blows out of, it's more about that the fan isn't running at all.
Like I said earlier, a new ignition switch allowed the fan to run but then I had no power to my windows. If I place the old ignition switch back in, I have power windows but no fan. (Actually, sometimes with the new switch in, the fan still won't work)

What does this seemingly electrical problem have to do with a plastic pin on a plastic door or am I missing something?

Thank you

ArtNJr 08-01-2012 03:49 PM

Sounds like you need to start with a new ignition switch & a service manual to see how the different parts of the system are interrelated. It's apparently all electric with no vacuum involved, so the different parts of the system will be hooked together in some fashion & a schematic of the system would let you track the problems down a LOT faster than trial & error.

starquestbd22 08-01-2012 04:06 PM

I think the reason that we got off on talking about the plastic limit pins and plastic doors (the common failure point on third gen trucks when air won't go where it is supposed to) is because you mentioned that you thought it might be your blend door because of the air blowing out two different vents when you had it on the floor setting. As I said in my post, I don't think this is your main problem. You could be correct about experiencing HVAC door problems (which would be mode door 2, not the blend door) secondary to your primary problem which is obviously the fan not running.

Normally I would say start by troubleshooting the fan motor, fan motor resistor pack, and the fan control switch. However, in this case I really don't see how it can't be related to the ignition seeing as how the swap made the fan run but caused other issues. Have you considered swapping the new ignition module for another new one just to make sure that you didn't, on the very off chance, get a new module with problems? Maybe someone else with a little more electrical knowledge will join in. I'm pretty familiar with the main HVAC components but I don't understand how the ignition could affect the fan motor alone and nothing else. Seems like to me it would either have power or it wouldn't.


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