L5wolvesf

The heater control assembly on my 84 broke recently. I moved the lower lever to the “warm” setting and heard/felt a snap and heard a small piece fall on the floor. The lever now moves very loosely and doesn’t change anything. I removed the radio (wasn’t working – maybe because of a horn problem?) to see what I could see and make room to work on the heater assembly, but that really doesn’t seem to give a lot of access. So my first question is:
Can I get the heater control assembly out, to repair or replace it, without removing the lower dash?

I also plan/want to clean out any junk built up in the interior heater area if there is access.

Second part of this project is the heater control valve. It looks pretty crusty and was a bit difficult to operate before the lever broke. I want to replace it before it locks up completely. I read on this thread >
https://www.yotatech.com/forums/f115/heater-control-cables-85-sr5-pickup-227415/
(on response #15) that an 89 4Runner heater control valve is a bolt on replacement, but in plastic. From my comparison, by looking at the Rockauto site, the parts look completely different and lack the mounting ears the 84 and 85 have.
Can anyone confirm or deny this? If there is a bolt on replacement in plastic does anyone have a part number?

I am also going to do a cooling system flush before swapping out the heater control valve.

The other semi related part of the project is cleaning out the area where the hood hinge is. I posted about this here >https://www.yotatech.com/forums/f115/hood-hinges-297933/#post52343434 . Two things I am considering there are:
1) Putting a window screen under the cowl piece to keep out leaves etc. I have this on a couple other vehicles and have a lot less junk going into those areas.
2) Placing some leftover blue poly swamp cooler pad material before the hinge to keep junk from building up in there but still allow water to pass through and drain away.

I also want to see if there are any obvious repairs needed to the A/C (yep doesn’t work either) under the dash. So my question on that is:
What are the most typical problems that make the A/C not work?
It was not working when I got it so I imagine it is out of refrigerant, but else what should I be looking for?

Last question (for now):
Does the horn pin really affect the radio as I thought I read about?

BTW, this needs to all accomplished while driving the truck more or less daily. So taking “everything apart” would be a problem.

If y’all want pics of this project or certain parts let me know and I try to do them.

Thanks
L

bootscootboogie

iTrader: (1)

Fun fact: you can drive this truck with the whole dash took out and nothing hooked up IE gauges, radio, etc, lol when I was doing my heater core I had to drive to work so I just did it. Just start taking dash stuff out. It's really not hard to take out or put back in. THAT'S how you learn where everything is!

osv

22re performance in chico sells heater control valves, but they are really expensive.

Terrys87

iTrader: (1)

Clogged Evaporator will keep AC from working... https://www.yotatech.com/forums/f116...trucks-286766/

On my Wifes 88 runner thread below is some information on getting access to the heater controls

L5wolvesf

Thanks Terry - great write ups BTW.

L5wolvesf

12/10 update. Today I removed the glove box, speakers (rotted out) and most of the trim/covers in preparation for the under dash work. I’m figuring I’m going to pull out what I can without removing the whole dash cover. I’ll inspect and clean out the heater area, evaporator et al and have those all done for when I tackle the A/C issues. The heater core is good so far but I’m going to take it to a radiator shop and have it gone over so I won’t have to think about it again.

Props to Terrys87 for doing the write ups he’s done – everything is as he has said it would be.

I’ve decided I also want to do the SR5 gauge panel upgrade – I like having a tach and oil gauge.

L5wolvesf

Here is where I'm at so far

Terrys87

iTrader: (1)

Swapping out a heater core is no easy task for a first time. I have done several and best I have done it in is 4 1/2 hours. Normal 6-8 hours. I think on my 86 Runner thread, I did an extended cab truck for a guy and show how to pull the dash a part to get access to a heater core. It not something I am worried about doing but not in no hurry to do another one anytime soon. If yours is good, clean, and working, I would not mess with it. Getting a correct replacement core from the part stores is a gamble as well.

L5wolvesf

Now that I’ve scored a decent dash pad I have to get the rest of my heater work done. Right now I have a question about my Heater Control Unit (HCU) which has a problem. As I mentioned on my first post – I moved the lower lever to the “warm” setting and heard/felt a snap and heard a small piece fall on the floor. I haven’t found the piece. With the HCU face plate off and dash pad removed I was able to see where I believe the missing piece should be. From other posts I’ve read I think the missing piece is a clip that holds the outer cable in place so the inner portion of the cable can move to change the “cool/warm” setting. I’m not sure exactly what mechanism it moves but I see that the cable goes close to and under the heater core enclosure.

In the following posts are my pics of where the missing piece seems to have come from. You can see an indentation where the piece/clip that held the outer cable left a mark. The blue thing you see is a tool I placed there to give some contrast to the parts – it is not part of the truck.

L5wolvesf

This view is from above the HCU. The missing piece/clip I believe goes in/near the round hole just above the blue tool where black end of the cable is touching it.

L5wolvesf

This view is through the blank space to right of the HCU. You can see the indentation on the cable better in this pic and a side view of where I think it may have been attached to a clip of some sort.

L5wolvesf

This pic is from another post that shows what might be the piece/clip I am now missing. I believe the white piece circled in red in the picture below is, or is similar, to what is now missing on my HCU – but I am not sure what is missing.

My hopefully simple questions are:
What is missing? Is it the white piece/clip I think it is?
Is it something I can purchase?
If not is there a known substitute piece or a fix?

Depending on what the part, or fix, is I would prefer to repair it without removing the HCU from where it is.


​​​​​​​

Co_94_PU

iTrader: (-1)

That white piece is the pivot for the selector arm, not a cable clamp.

I think the part you broke mounts under the plastic there in the photo

L5wolvesf

Cool that helps a lot. I looked at the control from underneath and saw that it looks like another pic I’ve seen taken by Terrys87. I’ve cropped the pic to focus on what I saw.

Now the questions are . . . Is it something I can purchase? If not is there a known substitute piece or a fix? A cheapo thing that comes to mind is using a couple zip ties in place of the MiA piece. Has anyone tried using a couple zip ties or something like that?

Co_94_PU

iTrader: (-1)

Doesn't really matter if the sheath isn't fixed at both ends, unless it binds..

55931 CLAMP, HEATER CONTROL WIRE

55931-10010 for an 86.

They might come with the cables also,

55909 Cable Sub-Assy, Airmix Damper Control
55909-89110

L5wolvesf

Thanks to Co_94_PU I think I've found a pic and a nearby source for the cable clamps.
I just want to verify with anyone here who has seen the part that this indeed is it.
Thank you.

thefishguy77

iTrader: (1)

Just duct tape a propane heater to the dash and call it good. Kidding. But all I got at the moment.

Co_94_PU

iTrader: (-1)

Nice maybe a job site tornado style one in the bed so you can play Batman!

Yeah clip looks about right

L5wolvesf

Thanks CO

L5wolvesf

So I finally got the heater cable clamps in my hands and installed on the heat (Cool - - - Warm) control cable. The lever and the inner cable now both move freely and are attached to the heater control assembly – I can see them move. The other levers and cables seem to work and operate correctly – I can hear the doors/diverters move under the dash.

But I have a problem – the heat control valve (under the hood) does not move when the heat (Cool - - - Warm) control lever is moved. It doesn’t even act like a cable is attached.

Keep in mind I’ve rarely used the heat or A/C in this truck. So my question is:
Is the heat (Cool - - - Warm) control lever supposed to operate the heat control valve (under the hood)?

a. If it does, does the cable go directly to the heat control valve (under the hood) or is there something/part in between?

b. If not which one does?

Thank you