Automatic climate control problems

[albi1cnobi1]

I think he is right. Just like the blower motor resistor in a manual system uses resistance to vary the motor speed, the EATC uses a solid state PWM controller to vary the voltage to the blower motor to control the motor speed. So his readings sound right. Ranger Rick, when you check the voltage at the motor connector are you using the ground on that connector or somewhere else? You should use the the ground in the motor connector to eliminate any possibility of it being a ground problem in that circuit. Follow me? But I think you are on the right track.

 

[budwich]

yes measuring a voltage DROP across a motor may be variable as that is how the speed control works BUT measuring for voltage coming into a device is done by measuring that point to GROUND... a known ground.... doing anything else may only confuse your testing.... especially IF there isn't a some form of ground involved.

 

[albi1cnobi1]

If his blower relay were bad he would have no voltage whatsoever at the motor connector. The EATC unit energizes the relay which sends 12v to the motor. The motor speed controllor then pulse width modulates the ground to vary the speed of the motor. If he is taking his readings at the motor connector across the pk/wt and or/bk wires the meter would see different voltages depending on what speed the EATC unit decides the motor needs to run at. If he measures the pk/wt wire to any other ground other than the or/bk in the motor connector then he is going to always get 12v. the pk/wt wire is 12v fused from the battery dist box to feed the motor. If in fact he is measuring correctly then those readings indicate that the speed controller is working correctly.

 

[Ranger Rick]

I was reading at the wires, I mean that I was grounding to the motor ground wire rather than a chassis ground. So, that sounds consistant with the description that albi1cnobi1 provided. When I grounded to chassis, I'm pretty sure I saw only 12V. And regarding the relay, I couldn't imagine any scenario where voltage arrived at the connector if the relay was faulty. So, I had a family function to go to this evening; I'll test jumper the motor itself tomorrow and see what that yields.

 

[albi1cnobi1]

You could also try the "rubber mallet" test. If you have a rubber mallet you could try giving the motor a few good whacks. If it starts to come to life, you've got a faulty motor for sure. If not, well it's probably bad but you just won't be totally sure. You can use a regular hammer, just don't go ape sh*! on it. Just a few light taps.

 

[Ranger Rick]

Well, I gave it a few taps with my fist, but it didn't make a difference. I will add, though, that when the fan first started to fault, it would come and go with bumps in the road. Seems like sorta the same thing...

 

[albi1cnobi1]

If you jump 12v to the motor, that may give it a kick to start. But most likely it will fail again. Try the 12v jump, if you get nothing you're off to NAPA. The motor is really easy to swap. you just have to put your fan on it if it doesn't come with one.

 

[Ranger Rick]

And it was off to the auto part store indeed. I just replaced the blower motor, and I now have fan-driven air movement. When I removed the old one, looking in through the vent hole, it looked like it was real dirty and worn in where I could see. So, anyway, good day so far...

Now that I have air movement, I now know that I have the defrost-only vent issue, but that EATC problem is at least well documented. Since I have the second EATC head unit that I got in a junkyard, I'll play with rebuilding that because, well, there's no reason not to. I also want to verify that the blend door actuator is operating, so I'm searching that next...

 

[albi1cnobi1]

Alright. Glad that worked out for you.Sounds like you've got it under control, you'll be riding cool again in no time!

 

[Ranger Rick]

I ran a self-check diagnostic on the EATC just to see and it came up 888, so I assume that the EATC at least thinks all is well. I also set about rebuilding the EATC spare unit. Unlike the references that I found online (mostly what I saw on f150online.com), the vacuum assembly on mine was not held together with a series of screws, but rather spotwelded. I drilled the spot welds from the underside, were there are dimples in the carrier chassis that the actuator frames would've used to locate on before the spot welding. A 1/16" drill was a big enough hole to allow me to pop the welds with a small flat screw driver. I'll have to use screws to reassemble, but I can probably uses some Schwinn headbadge screws that I have. That's as far as I've gotten at the moment...

 

[albi1cnobi1]

Make sure you hit "defrost" after running the test. That resets the unit and clears any codes. Run the test several times just to make sure, it has been known to miss sometimes. You mentioned a defrost only problem. You may find once you rebuild the EATC unit that the problem persists. That problem relates to a vacuum leak more than likely. In all the assembly and dis-assembly a vacuum line may have been jostled loose. Unless the vacuum diaphrams in the control unit are leaking, then the rebuild should fix that.

 

[Ranger Rick]

Well, actually, when I found that the air was coming through the defrost only, I swapped in the vacuum manifold from my spare unit (the one I was rebuilding was the OEM assy). And, when I went to test it out, everything was working properly. I had air coming through the vents and to the floor, on demand. So, I was pleased. However, when I took it back apart again to put all the hardware in (I'd only just set it together for testing), it reverted back to the defrost-only. I tried jostling the lines around (and the head unit) to see if it would make a difference, but it did not. I got a bit frustrated with it, so I stepped away from it for now. Actually, I hopped on a bike and rode into my village for an ice cream. It helped So, I'm still out of sorts on that issue. Hopefully, the vacuum manifold rebuild will help. I should be able to do that tomorrow evening.

The other odd thing that happened today is I lost the operation of the steering wheel buttons. Not just the EATC buttons, but also for the radio and cruise control. They all worked yesterday, I know that for certain. I looked in the owners manual for a possible fuse, but couldn't find anything that referenced steering wheel controls. So any help there would be appreciated...

Thanks.

 

[CDW6212R]

Check the horn also, but that would all be unrelated to the AC issues.

 

[albi1cnobi1]

Also check the clock spring ground, color is DG/OG. That's the only thing in common with both audio and climate. Diagram is on 1st page of thread. See if the cruise is working too.

 

[Ranger Rick]

The cruise is not working. I checked that as soon as I realised the other steering wheel controls were out. The horn does work, BTW; I was able to beep it with my remote when I locked it this morning.

On another note, this morning the EATC was directing air through the dash vents, floor outlet, etc. again. I don't know what might have changed, however I'm not going to question it at the moment. I'll keep an eye on it. If/when it reverts again, I'll install the rebuilt vacuum manifold and see where that leads. But for now, I'll enjoy the AC, since it's going to be hot and muggy here today...

 

[albi1cnobi1]

The only thing in common with all of those controls is the clock spring ground that goes to the speed control switch. (dark green/orange wire) Also check fuses #9, 10, and 13 in the interior fuse panel. (especially #10) They all pertain to the cruise control so they could affect whether that clock spring ground is there or not.

 

[Ranger Rick]

Fuse #s 9, 10, & 13 all appear to be good. The only other thing that comes to mind is that when I replaced the fan motor, of course, I had to relocate the cruise control servo during the operation. Obviously, I put it back when done, and I have no reason to believe that it would impact the other thing, but I generally don't believe in coincidences in this kind of situation, so I'm just trying to disclose anything that might be pertinent...

 

[Ranger Rick]

Got it. Chalk it up to mechanic boneheadedness. After my last post, I realized that I couldn't recall plugging the connector for the cruise servo back in after the fan-adectimy, and so I went outside to check. Sure enough, I'd left it out. So, apparently, faulting the cruise control by unhooking the servo also faults the other steering wheel controls. But clearly in the diagram, the ground from the wheel connects through the servo to ground, so it all makes sense.

The harness plug itself had gotten stuck under the washer fluid tank when I put that back in place, so I probably never saw it. Anyway, I quick checked that the buttons for the radio are in fact, now working, so I'm going to assume that everything else is until lunchtime when I check for sure.

Thanks for all the help in sorting this whole issue out. This was really the only major issue the vehicle had, even at 282K miles on the clock.

 

[albi1cnobi1]

Sweet. Yeah , been there, done that. Don't you hate when you work on something and you overlook something obvious like that. Well at least it wasn't serious. I'm glad I could help. This forum has helped me immensely so I like to return some help and knowledge when I can. Good luck. Al

 

[SidCharming]

I've read this thread and haven't noticed a situation like mine. 2002 Eddie Bauer Explorer with 247k miles. This past year, uncertain when, my heater kinda works. Noticed when it got cold outside (Minnesota). Heat comes out on driver floor, but passenger side is ice cold. I've performed the test (have digital Climate Control) originally had a bad blender door... replaced with part from O'Riley Auto Store. Thought I had the problem licked... Nope! Nothing but upset passengers. I performed the test again 4x and got 888 each time.

Where should I go next?