Stuck dash fan and heater controls

[titan3c]

The dash fan and heater controls on my car are so hard to move I broke one of the knobs off. I haven't got under there yet to see what the problem is, but by feeling I didn't learn much. Can't imagine what the problem is unless it's something similar to the hood release problem.

[raygreenwood]

Wo you broke off the plastic slider knob?

STOP NOW!.

This is a common problem and there are even more things to break. Its not hard to fix....a little finicky....but not hard to fix.

Yes...it is largely the same issue as the trunk cable.

If you look under the dash. ..pull your knobs off.....there is a slider assembly bracket with two cables.

There are a couple of bolts that hold the slider assembly in. Disconnect the battery, remove and mark the wirss. Unbolt the slider assembly.....loosen the cable clamps that hold the cables tight.

The cable clamps are important. They hold the cable still like a bowden tube. Without the cable clamps in place the flaps on the fan housing will not open or close all the way.

The slider assembly will back out and swind down on the cables....do not kink the cables.

You will see that the cables snap over split plastic pegs attached to sliding plates in the slotscof the bracket platr.......these pegs usually break off from stiff cables. When you break them they cannot be glued. The way to fix them.....is to get a screw....the screw that holds the fuel injection ECU plug handle onto the plug is perfect.....so pull one of those and go to the hardware store and get 3.

Remove the cables from the pegs so the plate comes out. At this point.....i use a dremel and cut tue pegs off flat. The drill a hole smaller than the screws.....and screw them in carefully. Make sure the height/depth allows the screw head to come down to maybe .005" above the little coil on the end of the cable. Make sure the screw goes all the way tjrough the little plastic slider....but does not protrude.


When you get the slider plate out and free of the cable....there is a,sliding metal clip with keyhole shaped slots in it. Slide it off......and you will see how it all goes together.

Lubricate the slides with synthetic lube likd superlube or even dielectric grease. Do not lose the two small plastic centering bushings.

Treat the cable with ATF just like the trunk cable. Put a little synthetic grease on the flap pivot points. In fact....you will likely find that the foam that seals the flaps is,shot.

I removed the fan assembly and glued in very thin neoprene and it seals up nicely. That part is redious because you have to fit and trim and fit and trim to make sure the cables can exert enough leverage to compress the foam without holding the control levers half open. They only exert full pressure at the end of their stroke.
Ray

[titan3c]

OK, I get it, but clue me in as to where the fuel injection ECU plug handle is. I'm not that familiar with all these parts of the engine.

[raygreenwood]

If you have a wagon....your fuel injection ECU....is under the right rear armrest. In the sedans the ECU is under the oval lid in the left hand side of the engine compartment.

If you remove thr ECU....you dont need to unplug it. ....but remove the strain relief screw and underneath is a plastic flexible pull handle that helps you remove the plug.....and at each end is a black screw. These screws are screws whose threads are optimized for plastic. You can buy screws like it at Tru value hardware.

I will try to find a spare and see if i can find a size. Ray

[titan3c]

OK, yes I know what the ECU is. I just didn't know what it was called. Thanks

[titan3c]

I am just now getting around to working on this, and have a question. How do I loosen the clamps on the cables. Can't quite figure that out. It may be simple, but before I tinker around with it just thought better to ask. Bob

[raygreenwood]

Hey! Great to see you here!

So...first....what exactly do you want to do?

You do not want to release/remove the clamps on the cables....those little crimped rings. Its not necessary....and not getting them back on the same way ...will affect the cables and not let you fully open or close the flaps.

These are bowden tube cables. The exact bend, arc and position on the cables is relatively critical to smooth operation.

If there is a fan switch problem.....you first remove that single strut bar under the dash that is blocking the switch.
Then....disconnect the battery...trust me....been there and almsot lit myself on fire

The...and this is going off memory.....there should be a couple of 6mm bolts that come out and hold the switch plate in place. Mark the wires and pull them off. Then pull off the knobs from the outside. The switch plate pushes backwards and comes out from under the dash...swings down.....with cables attached.

If the plastic lug that holds the cable to the slide is snapped......very common.....you can disassemble the switch by removing the sliding square, keyhole spring nut from the rivet that holds the parts together. Then file the broken plastic lug off flat.....then find a machine screw that is just a few thousandths smaller that the hole in the end of the cable. It needs to be a snug fit. Any slack and the flaps will not close all the way.

Then drill a small hole about half the screw diameter ....where the broken off lug was.
Then...clamp that plastic slider down.....to hold it still.....and use a candle, solddring iron or torch to heat that screw until its hot enough to melt the plastic. Then rapidly screw it into the hole as straight as possible.

Ot needs to be long enough to form threads all the way through. Let it cool...then screw it out.....then cut it to length with a Dremel or file.

When you put the cable back on...screw the screw in tight and then back off 1/2 turn.

There are no adhesives I have found that stick to this plastic.....so this method works best.

Lube the switch slides with silicone based dry lubricant stick from NAPA. Ray

[titan3c]

Ok, the fan switch is working fine, but the other one is stuck. Bob

[raygreenwood]

[titan3c]

I think your correct-----the cable needs lubricating. Ok, I'll give it a try. Bob