EATC Blend Door - No Power

[GJarrett]

I thought I had the blend door actuator problem discussed many times on this forum, so I took the trouble to remove the old one and get a new one.... what a royal pain that back bolt is! :frustrate

Just to check all possibilities before reinstallation, I disassembled the old actuator and inserted its gear into the blend door hinge and used the old gear as a "doorknob" to move the blend door back and forth and it works fine. So I know my blend door is not the issue. Ok, so then it was time to check the actuator.

After all that trouble of removing the old actuator, I hooked up the new one before installing it. I played with my temp controls all the way from Max A/C to full 90 degree heat and the actuator never moved. I checked my owner's manual and found that fuse #10 seems to be the one controlling the actuator so I checked the fuse and it is fine. At this point I'm scratching my head :scratch:

It seems that I have another control issue of some sort. I did find another thread wherein someone mentioned the possibility that the entire dash A/C control panel may be the culprit (the one that has the readout of temperature).

I've already chased this with $40 in tools to get that d@m# back actuator bolt off and also the price of a new actuator I didn't need, so I'd like to make sure before going further. Has anyone else had this problem? Is there a way to diagnose the panel [with voltmeter/etc] to see if that is the problem? Is there another fuse and/or relay under the hood that might be fried? Could there be another thing that is causing the problem?

 

[budwich]

well... since you have the thing apart, how about checking things with a meter at the connector to the door motor.... checking to see if indeed you have power there AND as a "dry test" on just the door motor... place power on pin 8 and a ground on either 1 or 5 depending on which way you want the motor to run, this will check the operation of the motor itself.

And of course, check all your fuses... there are some for the controller and the one for your motor. Use a meter, looking at fuses is like looking at a woman, she might be good looking but when it comes down to it, she ain't no good. check your grounds also. Money's on a fuse or broken wire.

 

[GJarrett]

In looking at the pins, which ones are what numbers?

 

[budwich]

should say on the connector / cable... don't have a picture.... but pin 1 is O, pin 5 is DB/LG and pin 8 is GY/Y (at least in 96).

 

[GJarrett]

I'll check it next week..... I'm out of state working right now. Thanks for the help.

 

[joey_hv]

GJarrett seems to be having the same problem I am having except for my actuator actually had broken gear teeth.
I was able to test my motor with 9 volt battery and it worked. Now I am still not getting any voltage to the connecting harness and al fuses are fine.
Thinking about pulling out the AC control module to see if anything obvious is wrong.

 

[budwich]

well if you ain't getting no voltage at your motor, then it ain't your control module .... caaaauuuusssseeee .... the voltage delivered to the motor doesn't touch the control module.

 

[96ExplorerLtd]

I have the same problem on my 2000 Ltd Explorer with climate control. The blend door is fine, the actuator works great with outside power, I've inspected it inside and all gears are fine, I cannot detect any power on any pins when changing heat settings or changing from Max AC to the other settings. In fact I went to a dealer and talked them into letting me plug the replacement part into the wiring harness and change settings. The actuator on the new unit didn't work either. I conclude that there is an electrical problem. I've checked fuses. As far as I can tell, the fuse in position 10 is the only fuse related to this operation and it is fine. In fact the other things that are fused by #10 work fine.

Please help!!! I need to understand the circuit that feeds the actuator or the control unit that sends power to the actuator. It seems as if the thermostat works fine and all the other controls seem fine.

Thanks,

Ron Mellon
2000 Ford Explorer LTD

 

[GJarrett]

I never got around to finishing this because I broke my torsion bar mount and have to get the thing moving again before worrying about the A/C... when I finally get around to addressing the A/C again I'll share what I learned. But it will probably be at least another month before I get my Explorer rolling again, maybe longer.

 

[budwich]

The power feed for the blender motor comes from the fuse as indicated. With a meter, check to see that power is leaving it.... and of course, it is as in this case that particular fuse feeds "hundreds of things" that you would have noticed. Sooooo, your likely cause is a broken splice or wire... money on the splice. All those "things" gets their "juice" from a splice near / behind the instrument panel. Go there and ye shall find power...from there, ye shall seek the wire towards the blender more and find nirvana (break) along the way.

 

[96ExplorerLtd]

Thanks for that confirmation. I'm thinking that by removing the radio, I'll be able to see the blend door actuator wires coming from the climate control panel that is just below the radio. It must be that the power from fuse 10 is going to the climate control panel, powering it and (through the climate control panel) powering the blend door actuator.

Have I got this right conceptually or is there a power lead directly from fuse 10 to the blend door actuator? I don't see how that could work.

Thanks for the help.

Ron Mellon

 

[budwich]

Nope... you don't have it right..... my statement earlier was pretty clear... I hope. "well if you ain't getting no voltage at your motor, then it ain't your control module .... caaaauuuusssseeee .... the voltage delivered to the motor doesn't touch the control module." Most control systems DO NOT switch voltage, they switch grounds. This one is no different..... as I said "seek and ye shall find" by tracing the wire from the splice to the motor... don't worry about your controller.... at least in my 96 drawings.

 

[96ExplorerLtd]

Thanks Budwich, I appreciate your attention. It seems to me that if I have difficulty finding the break in the power source, I can simply splice a new wire from fuse 10 to the power lead on the jack that plugs into the actuator. My next challenge is to determine which wire is power. The color scheme on mine is different from the 1996 wiring diagram I found on line. Hopefully, the wire color coming out of fuse 10 will match with one of the wires in the jack. I think that will be the power lead. Any suggestions?

Ron

 

[budwich]

I am not sure I understand your statement "My next challenge is to determine which wire is power".... with your earlier post of "The blend door is fine, the actuator works great with outside power".... you had to know where to hook power to get the actuator to work during your test... that pin is the color code of the wire you want to trace back to the splice regardless of what I indicated for a 96.... maybe I am confused????? maybe the circuit is "really" different... could be.

 

[96ExplorerLtd]

I opened the housing to the actuator and applied a 12v source to the leads of the motor inside. I don't think I can trace that backwards because those connections are soldered into a circuit board inside the unit. If someone has a 2000 explorer wiring diagram and can tell me which lead is the power lead, I'll appreciate that. If not, I'll figure it out by trial and error. There are only 5 leads.

Thanks, Ron

 

[budwich]

OK... that helps my "confusion".... I suspect the pin numbers that I posted earlier are the same. You should be able to go from there.

 

[dcdyd]

I bring this thread live because now I am having the same thing. My blend door doesn't move but the actuator works well. I opened the actuator and tested the motor.

Has anyone figured out what was wrong?

 

[white_shadow]

what is a "blend door"

 

[dcdyd]

The blend door is used to control either cold or warm air you get from the vent. It is a component that gets broken often. But the actuator that moves the blend door also may have problem. See this thread for various dicussions. In addition, searcj 'blend door' for more information.

 

[white_shadow]

The blend door is used to control either cold or warm air you get from the vent. It is a component that gets broken often. But the actuator that moves the blend door also may have problem. See this thread for various dicussions. In addition, searcj 'blend door' for more information.

the quick fix would work, but we can have wild temp swings here, need heat in the am, and ac in the pm. i was reading the thread about actually replacing the door. im gonna have to do this pretty quick. i only have cold air sitting still at a light, moving i get hot air.