So how do you get this thing out? I have problems with the heat lever not moving and fan not working. With glove box & stereo out, I can see that the problem with the lever is that the screw or bolt it rotates on has fallen out. However, I can't figure out how to get the panel out so I can work on it, or check the fan switch.

Shop manual doesn't seem to have anything on removal, just doing electrical testing. Chilton manual just says "remove heater control panel" as part of removing heater core (which I hope I don't have to do), but nothing about how to do it. Found a couple of threads here about removing the core, but pictures are gone with PhotoBucket :-(

Also, if anyone has info on what size bolt is used for the lever pivot, it would be much appreciated. And since the plastic panel has a few bits broken out (guess they never expected the plastic to have to last 30+ years), does anyone know if there's a source for replacements?

 

Also check U-tube videos. I found some good info for my '89 pickup blower system on the tube

 

I just did this job this summer on my 86 truck as that plastic pivot piece broke as well. I'd guess a 1/4 bolt with flat washers on each end would work well as a new pivot. Once you have it out take the assembly to Ace/Home Depot to get the right fit. I didn't chance it and went with new assembly.

I bought a new Toyota OEM lever assembly from Toyota Parts Deal (Part No. 55910-89136) for $79. Good news is has there is HD metal bolted pivot with support plate there now and not that plastic one. Well worth the price. I also bought a replacement 'blue' heater valve cable that was stuck and caused too much stress on the OEM plastic pivot. Tried to work it lose and no luck. It was Toyota Parts Deal (Part No. 55906-89110) for $11. I did work and silicone sprayed the other cables to loosen them up a bit as well. Not a lot but they weren't real bad. That's the easy and great part.

Installing the cables to the new lever assembly was a pain as it came with the clips installed so you have to remove them 1st. Take a lot of photos of the existing cables to see where they attach and which way they go. Once they are out the assembly it was confusing. Getting the new clips out took a while to figure out. I found pushing up just one of the two side locking ears all the way out would release the other side once the pressure was off. The tip of a small needle nose pillar worked well. Once all the cables were installed intoi the new assembly, I install a small cable wrap around the clip support and over the cable to provided extra hold strength. My OCD kicking in. The cables move very easily now

The worst part, as you have found out, is removing and then installing the lever assembly. You basically have to remove the dash on the right side to pull it out a bit to slide the lever assembly out. Remove the instrument cluster cover to get the to dash pad left top bolt out. Then the radio and stowage box so the lever can slide down. The center console to support bolts to allow pulling the dash out for clearance. The metal cross bar that the glove box hinges screw into. The right side screws holding the speaker box area to the sheet metal. I bought some interior panel screws from ebay and ended up using them as I lost a few.

I removed the instrument cluster to install a new speedo cable as well, but only the upper housing has to come off the access the dash pad left bolt. There is a right side dash bolt as well located behind the right dash vent. You have remove the vent to get to it. Gently pry the vent out. It has upper and lower lock in place metal stabs. Be very careful. I shattered mine on a previous removal and never put that bolt back in. Just wrapped the stud with white medial tape, so it fit snug and didn't rattle. Add more tape as needed with trial fiti-ups. Worked well as not loose nor noisy. Now makes removing the dash pad so easy. I have done it a few more time. You can see the white blob in the picture. It works well.

Then you will gently pull that loosened dash out enough to slip the lever assembly to the right and out the glove box opening.

The good news is now that you have that dash out, you can inspect all the duct work for crack of loose fittings and seal them with Gorilla weather proof duct tape. It sticks very well to cleaned plastic. I had a slight 'breeze' i could feel coming from the right side of my center console Turns out the AC to Heater box joint was loose so fresh air was circulating. I realigned them and wrapped the joint as well as some lengthwise strips to prevent future separation. Breeze gone and more air flow out the vents. Also had minor crack in the defrost ducting that I use the 2-part J.B. Weld and a cheap pipe solder paste brush to apply it to seal and strengthen the plastic.

The sliver closed cell duct insulation was added by me awhile back to help keep the vents from absorbing summer heat for quicker AC cool down. Good time to make any repairs, cleaning, lubrication, sealing, that might be needed after 30 years.

Good luck as it is a huge pain in the ass.

 

Just what I needed, another huge PITA, after I spent last weekend replacing the convertible top on my Miata :-( Maybe I'll just push the heat valve all the way on, and leave it that way until spring.

Thanks for the Toyota Parts Deal suggestion: looks like they have a lot of useful stuff that's hard to find.

 

Mine broke last year (recent) so I did just that, Went under the hood, disconnected the heater cable, opened/ closed the valve lever for the season and use a small tie wrap to hold it in place. That heater level has 2 cables on it. One to operate the heater core valve that pushes to close and one that opens/close a duct flapper between the AC box and heater box the pulls when the heater valve is closed. They work in opposite directions- push/pull

So you have to do both accordingly, especially in Summer if you have AC. I do and I did. It did the lever job as I bought the part first not knowing the pain. I'm glad I did as this is my only and daily driver. It was a pain but not difficult and I did a lot of extra work while it was all apart. To me keeping it working like new is key to not having a junker.

The metal pivot on this new one is substantial, GUess they figure out the stress was too much and fixed the part. That was a surprise as I was going to slip a bolt, washers , and nut down the center hole if it was plastic. The cable routing and which lever, which way had me. The pictures save me even then I had to check them often.

Not hard just a lot of work.
I have a lot of links to parts and check them all when needed.

I would not want to do that job now in cool/cold temps as I worked in my parking space. A heated garage OK. Open the heater valve and wait until Spring/ Summer

I had a 1978 Fiat 124 Spider and that convertible top was an easy replacement.

 

Lucky mine's a second vehicle, for hauling stuff, dirt roads, and snow too deep for the Miata. Though I have A/C, it hasn't worked in a while (but I hardly ever need it, around here). And in winter I can always wear warmer clothes :-)

 

Then open the heater valve for heat and close the AC/Heater core flapper valve located under the right side duct work (follow the cable) by pushing it in all the way. You're good to go. Plenty of heat. Reverse it is Spring and Summer.

In SE VA, if the sun is out the cab heats up quickly as there is so much glass area. I rarely run the heater in winter.

 

So after a few mostly non-related delays, I finally had a chance to work on this today, and it seems that the heater valve (the one on the firewall, under the hood) is stuck. Which would explain why the control lever broke, trying to move it. Is this something that can be taken apart and fixed, or should I just order a replacement? They seem to run about $130 or so, from a quick search.

 

Check Ebay as a lot for less. Mine leaked a while back so I replaced it and it was $180, but as a daily I needed heat control. When I replaced the HVAC lever assembly I found out the 'blue' cable that conencted to the heater valve was completely stuck. Even when removed I could not free it up. That's slow freeze up to end stop over time caused the lever plastic pivot to break. Bought a new blue cable and the new level has a metal reinforced pivot unit. Shouldn't happen again.

https://www.ebay.com/itm/26523760632...SABEgJgv_D_BwE

 

HI... did part number 55910-89136 fit fine in your 86 pick up? I have an 88 and need this whole assembly but the site says it wont fit my 88. But, if it fit you 86, then it should fit my 88

 

Per the online parts diagram, 55910-89121 fits 8/83 - 2/89.
https://japan-parts.eu/toyota/us/198...r-duct/1#55910
Click on the 55910 in the diagram to see 10 digit part # with years.

Toyota Parts Overstock shows 55910-89121 is superceded by 55910-89136 and it shows '88 in list of what it fits.
https://parts.lakelandtoyota.com/p/_...591089136.html

Go for it. If it doesn't fit you can return it to Toyota for refund. Not a bad online price of $79.65. Check a local dealer the price may be lower than Toyota Parts Overstock. My local dealer shows it at $76. You can save shipping costs by picking up from local dealer.