How do you get the fan switch out from behind the trim panel of the Toyota Previa?

Answer 1

Tools: Philips screwdriver; small flat blade screwdriver. 2 feet of wire - bell wire or twist-tie or craft wire; a hook-ended tool or large paperclip straightened with about a quarter-inch hook on the end. Flashlight.

Disassembly:

The first two steps are fairly well described in the Chilton manual for this vehicle, the rest are not.

1) Remove the ash tray/cup holder assembly.

Open the storage door under the ash tray, remove the ash tray, and pull open the cup holder. Remove the 4 screws that hold the assembly: 2 of the screws are in the top behind the left and right ends of the cup holder, one is in the lower right ashtray opening and one is hidden just behind the lower left corner of the trim around the cigarette lighter socket. Wiggle and force the assembly down, lowering the left side first and getting it out diagonally. Disconnect the cigarette lighter plug and the lamp wire plug. The lighter plug pulls right off, the lamp plug has a catch you have to depress on one side, then pull off. Set the assembly aside.

2) Remove the radio/vent assembly.

Pop off the fuse box lid, the catch is just under the center front edge, depress the catch and lift the lid completely off. (If you didn't already know that, reconsider the decision to do this job yourself.) Remove the four screws at the top front. The two outer screws are for the trim panel and the two inner ones are for the control assembly. The trim panel also has two gold-colored screws underneath where the cupholder was removed. Look underneath, they're towards the front and go upwards. Be careful, the holes punched in the steel dash framework are not deburred and are very sharp. Lift the radio/vent assembly up and forward. Unplug all the radio connectors and set the assembly aside.

3) Now it gets interesting - loosening the control assembly.

Remove the two lower screws holding the control assembly in place. It should now be loose but still connected by several wire bundles and control cables. DO NOT remove any of the control cables, and the only wire bundle you have to unplug is the one going to the fan switch. Pull the knobs off all the control levers. Remove the faceplate, it's held by plastic latches on the sides and bottom. Remove the clear plastic light guide, it is held by a latch on one side and a tab on the other. Unplug the fan cable which is back and to the left. On my Previa this plug, and also the replacement part, had thin layer of foam around them. This plug, like most of them, has a small catch on one side that you have to depress to pull it apart. You should be able to manipulate the control assembly up and down a few inches and tilt it to view the top and bottom, but it will not come out.

That's it for the easy steps. The switch body itself is barely visible at this point. Before we go on, I have to name the two primary access holes to the fan switch.

The Slot. Notice that there is a wide slot in the left sidewall of this compartment that you can reach into, from just in front of the rectangular vent pipe opening on the left. You have to do much of the switch and cable manipulating through this opening; that's where the long fingers will come in handy. I will refer to this opening as The Slot. You can reach through here and get to the fan switch back side and connector.

The Hole in the Top. This is the opening in the top of the control assembly between the rear heat control lever on the left and the 3 electrical pushbuttons on the right. Through this opening you can see the whitish fan switch and the right side of its connector. You can also see the wires to the two lamps.

4) Remove the short fan switch cable.

This very short cable runs out of the back of the switch and is clipped to the back of the control assembly. Look at the replacement part to see what this cable looks like. Notice where the plug latch is located and where it hooks on the switch body. You have to reach in through The Slot, depress the catch without seeing it, and pull out the plug. It helps to also push the plug out with the screwdriver from The Hole in the Top. After it is disconnected, reach underneath the assembly to push the cable to the right to unhook it from the rear catch. Set the cable aside; you won't need it if you got a replacement with the fan switch.

5) Remove the two lamps.

For some indecipherable reason probably having to do with ease of factory assembly, the two little green lamps that light up this control panel are wired into the fan switch. You will curse this feature a lot very shortly. To remove these lights the lower one twists clockwise and then pushes in, while the upper one just pushes in. There are four little catches around the outside of the upper lamp's socket that you may have to press in a little to free the lamp.

6) Remove the fan switch.

There is a little trick here that stumped me when I tried replacing this switch on the first attempt. Slide the Rear Heat control lever all the way to the left and look at the lever arm, visible on the top of the assembly. Underneath this lever arm, just behind the front panel and about half-covered by the arm is a tab made of the black plastic control assembly housing that acts as a catch to keep the fan switch in place. Lift this tab with the flat blade screwdriver and push the switch to the rear by pushing in on the switch's control lever from the front. The switch body should easily slide back and out of its track. Two years. Now the switch can be removed from the assembly by sliding it out to the left and through The Slot. You will have to wiggle it into a diagonal position to get it through The Slot, and this will take some pushing. Before you can remove it completely you have to fish out those two lamps using the hook tool through The Hole in the Top. Back the switch into the vent pipe to clear the lever arm, then remove it and set it aside without throwing it across the yard.

7) Put in the new switch.

At this point a typical manual will say something like "Install the new switch in the reverse order" and then move on to adjusting the hood latch or whatnot. But there are those stupid lamps to deal with so I will press on. I used a combination of a pull wire and the hook tool to get them in place. I cannot describe exactly what I did, though somewhere in there came most of the cussing. I will describe the procedure as best I can. Take the 2 feet of wire and pass one end of it through The Hole in the Top, past the place where the switch was, out the left side of the assembly and through The Slot. Wrap the end that went through The Slot around the two lamps' wires, just behind their sockets. Wrap them well (3 or 4 wraps) because you are going to be pulling them through the assembly by that wire to keep them ahead of the switch body. You can't just stuff them in there ahead of the switch because they get all jammed up and going in the wrong places, and you have very little access to get them going right. You might be able to manipulate them just using the hook tool through The Hole in the Top, but the pull wire helps. At least it did for me, before I pulled too hard and it let go and I had to start again a couple times.

Put the switch body into the vent pipe, rear side in first; I think I had the top of the switch facing to the left. Put the switch arm through The Slot, pulling on the lamp wires to keep them moving ahead of the switch. Turn the switch so it is topside up as you get it through The Slot and into the left side of the assembly. Keep pulling the lamp wires out of the way. I got one loop of wire caught between the switch body and the control assembly frame at the bottom of the switch body, which I found out later because it made the wires too short to install the lamps. I had to unlatch the switch and slide it backwards to free the wire. You could see the stuck loop through the bottom of the assembly, so keep an eye on that lower opening as you install the switch. I considered just cutting off those lamp wires and living without a lighted control panel, but I already had the switch jiggled in through The Slot.

Get the switch lever arm through the front panel opening, check those lamp wires again, then slide the switch forward until it clicks into place, keeping it pressed upwards so the small projections on the sides of the switch body stay in their tracks. Fish the lamp wires along the right side of the switch and down the little tunnel that leads to where they mount through the panel. Be sure to fish the lower lamp first, the one that pushes and turns to lock in place. Lock that lower lamp by putting the bulb through the hole, aligning the two little tabs, then pushing from the back with your fingers. Lock the lamp in place by holding from the back and pushing counter-clockwise on one of the tabs with the flat screwdriver until it is fully rotated in place. The upper lamp has to be fiddled with the hook tool to get it to poke through its hole, then push it from behind hard until it seats properly. There was some more cussing required at this step - that lamp is hard to get fingers on.

Get the short cable and insert the plug in through the back of the assembly, clicking it into the rear of the switch. I don't recall the exact path the short cable takes from the switch and out to the rear left of the assembly, but you understand why I'm not going to take it apart and look. Feel around the back and slide the cable leftwards into the rear clip. Then reconnect the other end of the short cable to the wire bundle. At this point you should reconnect the power if you disconnected the battery, then turn on the ignition and make sure the fan works at all the speed settings. Breathe a sigh of relief.

8) Reassemble the control assembly.

Replace the light guide, be sure to put the tab side in first, then click the other side in place. Click the faceplate back on all around. Push the control knobs back on all the levers. Make sure all the levers still move through all their settings and all the switches perform their functions. Make sure those two little lamps light up when you turn on the headlights. Put the assembly back up where it belongs and put in the four screws, two at the top and the two on the lower arms. Check every control again.

9) Replace the radio/vent assembly.

This is a good time to clean and lubricate those vent shutters and replace the radio with a more modern one. Otherwise, reconnect the all radio wires and make sure the radio works through all the speakers. (I forgot this step and did not discover the radio did not work until all was reassembled. That's when I decided an upgrade was called for, so I could claim that I meant to re-disassemble everything. Yeah, that's the ticket.) Press the assembly back into place and put the top 2 screws in. Reach underneath and replace the two lower screws. Put the top lid back on the fuse box. Reprogram all the radio station buttons, because all the settings are lost when you disconnect the power.

10) Replace the ash tray/cup holder assembly.

Plug the cigarette lighter and lamp plugs back in. Note the lamp connector can go back in either orientation. Insert the assembly diagonally with the left side lower. Wiggle and force it back up into position and put 4 screws back in place. Put the ash tray back, close the cup holder, and close the lower storage drawer. Check that everything still works. Celebrate.

11) Epilogue.

Repair the old fan switch and toss it in the junk drawer. My old switch failed at the connector contact, melting the connector casing a bit. It must have arced for a while, working intermittently before the contact was lost completely. If you just trash the old switch pull out the two little lamps and save them, just in case one of the new ones burns out.