lgs 85yota

Does anyone have any experience with heater control cables on '85 SR5 or similar vintage pickup?

This is the 2nd time the heater control cable has come unhooked from the temp control slider inside the dash

It is difficult to get the cable end back into the small hole is the end of the control slider, as there isn't much room to get your hand through the small opening once you remove the cover panel

Given the cable doesn't move smoothly, I am thinking of replacing the cable this time, just uncertain how involved this will be with routing inside the dash & through the firewall

Also, if I may need to replace the toggle levers (temp & selection control) assembly

Yet to contact Toyota dealer and find how expensive the parts will be, assuming all are still available.

Thanks!
lg

AmpedRunner

Same issue with mine, though I managed to get it to stay on hot lol. now I just need spare time to fix. They are a pain to fix but if you take the dash off it is allot easier. Your local pull n' save might have the parts.

lgs 85yota

What did you do to get it to stay on hot?
I have pulled the cable where it attaches to the heater valve both directions (to the front & back) and it still blows cold air...
Just wondering if I have other issues to deal with

How do you pull the dash off, assuming the top part?

Thanks

AmpedRunner

It is possible their are other issues, All I did was grab the cable with two pliers(one for the cable the other to hold the cover) and moved it to the hot position. I don't remember if you have to pull it out or push it in to do this. With the dash, assuming yours is similar to mine, there are literally dozens of screws holding it on in various places. The top part is pretty much one piece so all the screws need to come out. Their probably are some plastic tabs too so be careful. 25 year old plastic gets pretty brittle

Yellowtruck

I can answer that. I'm having exactly the same problem, except that my heat/cold control wire didn't slip off, it broke.
I still have heat or cold. I followed the wire to the firewall, under the hood. There is a valve on the inlet hose to the heater core that is controlled by this wire. One way opens it to allow flow and the other closes it. Your wire probably slipped off while it was in the closed position, not allowing hot water/antifreeze to flow through your heater core. You can use pliers, or your fingers, and move this valve to the open position to allow flow.
I had to take apart my dash to get better access to this wire. I'm stuck wondering what option I should take: try and repair the wire; leave it and do nothing; or replace the wire, which looks to be a pain.

xxxtreme22r

or rig up a choke wire to control the valve.

Yellowtruck

I'm still trying to fully understand something....
On my truck, there are two wires controlled by the hot/cold lever. One to the valve on the otherside of the firewall and the other for the flap to the heater core. The wire through the firewall is the on broken on mine. I pried open the valve to allow flow to the heater core which gives me heat when the lever is in the hot posistion. When the lever is in the cold position, I get cold air. Typically, when this lever is moved to the cold position, the (broken) wire would close the valve that allows flow to the heater core.
If I were to not replace this wire and kept that valve open allowing hot water flow (especially in warmer weather when my heat is not needed) would that cause harm to my heater core?? If I can adjust the temperature from inside my truck with the wire to the valve broken, what purpose does this wire serve other than to allow the flow of heated water?

xxxtreme22r

The wire also directs air flow over the heater core. If you move that slider fast enough ou should be able to hear that door open and shut. Just like you can hear the vents move with the other slider.

No you will not damage the heater core with constant flow. I have no problems with mine and I have completely removed and bypassed my valve. Been driving the truck almost a year like that on what I believe is the original heater core.

Yellowtruck

That's good to know! I definitely hear the door open and close. Right now my entire dash is pulled apart so I could find that broken wire. I didn't want to put it back together until I had an answer and decided what to do about this wire. Though, with the entire dash apart and being able to locate almost the entire lenght of this wire, I am tempted to see if I can pull it out and replace it. Looks (kinda) easy, but I have a funny feeling that the looks on this one are deceiving.

xxxtreme22r

it might be easy, but I don't think that cable is cheap. I don't know though as I have never had my dash apart yet. My cable don't move either, but my valve leaked a little too. Which led me to just remove it till I can get my hands on a replacement.

Yellowtruck

Yeah, I'm afraid to get a price from the dealer, but don't have much time to scavenge yards looking for one that may or may not be in better condition than mine.
Plus, I hate doing crap like that when it's always raining.

lgs 85yota

Update:
Surprisingly the cable was still attached to the temp control lever

The problem is with the plastic fastener that is the pivot for both the temp & selector levers

The plastic fastener goes through the hole in the centers of both levers along with the pivot point mounting bracket that is attached to the control assembly

The bottom of the fastener has small tabs/ears that stick out to hold the bottom lever in place, but apparently after 25+ years of normal wear & tear it has worn off enough so the bottom lever will not stay on

With the ash tray removed I was able to get the lower lever in place and hold it and then move the temp lever to hot and the selector lever to defrost
It is fairly tight so there is only room to work with 1 hand through the dash

At least there is heat and directed to defrost now

Toyota doesn't list the plastic fastener separately, you apparently have to purchase the entire heater control assembly

Replacing the assembly would be a pain because it is very difficult to attach the 4 control cables
At least from my experience before when the cable detached from the control lever

I have been thinking of what may work in place of the plastic part
Maybe a brass stove bolt or a lock pin with a washer below the lower lever before the cotter pin
Either may be challenging to get it in place

Ideas?
Thanks

hiltu

ive only scanned through this thread but what might be causing some of the issues listed is on 88 and earlier trucks, the heater control valve is metal. in 89 they switched to plastic. My metal heater control valve is almost seized due to corrosion, the cable broke due to force needed to operate it. Ebay has the plastic heater control valves for cheap.

se7enine

iTrader: (2)

I've been wanting to switch my heater control valve to the plastic one but for now mine still works but the cable that controls where the heater blows broke. I can still control that one by the lever by my shins under the dash.

myyota

Its common for the original brass heater valve to corrode and freeze up or leak. When i got my 86 4Runners the heater valve on it was toast, so i swapped it out with a heater valve from an 89 4Runner, it was a direct replacement.

jkent

I'm considering doing just that! but where to put it? I have mine set to defrost but with summer coming it would be nice to turn it off and on when needed.

xxxtreme22r

the valve has nothing to do with the controls to control defrost, floor, vent etc etc, only the coolant flow through the heater core.

Logan1985yota

I had the same problem with my cable coming off the temp selector (unfortunately I broke my cable's hook when I went to put it back on). I was wondering if somebody could tack-weld the cable onto the switch so the hook wouldn't come out as often (though I have never done it). Just a thought I put out there for you guys.

Gabriel

I have an 1988 SR5 and here is a cheap easy fix. Buy a 3/4 water valve in the PCV section at Homedepot, it cost me about $11. The valve I got is for 400 PSI, which is overkill since the radiator core probably runs at about 12 PSI. The valve has tubing on both sides that easily slide into you heater hoses. Don't buy the 1/2 inch water valve since that would be to small in diameter.

I first removed the old valve, which was stuck shut. Then this part is important, I disconnected the return line in order to flush out the radiator core using a garden hose. I didn't use high pressure since that could damage the heater core. I first ran water through the return side, the side that doesn't run through the valve. You do this to go against the direction water usually runs through to unclog the system, then alternate to the other side. Eventually the water gets clearer and clearer. If this is unclear, watch a video on youtube in how to flush out your heater core. Eric the car guy suggest CLR to clean it, but it is corrosive to aluminum, so he only lets it set for a short while.

Note, the hardest part about removing the original valve is the clip holding on to the cable. I pinched the clip with a needle nose, and it unclipped. So this part clips back on and off. I didn't know this until I tried taking it off.

After flushing the heater core, I connected my new valve and return hose. Start the engine, then go turn on the heater. If your cables are messed up, go to the passenger side and in the bottom toward the center you can see a cable that controls the AC/Heater blending door. Turn it so that air blows out for the heater, even though my cables are messed up, they still move enough to let me know if i'm actuating the blending door for the AC or Heater. Next, on the driverside the vent blending door can be manipulated because theres is a section in which it slides toward the fire wall for defrost and toward the driver seat for vent. So I adjusted mine so air would go down and through the vent.

Make sure the water valve is open, feel both water lines going into and out of heater to make sure they are getting hot (which means the heater core isn't clogged up, but it should be as long as you flushed it out. Don't skip flushing it out if your valve was stuck shut, you do not want all that corrosion going into your cooling system).

This method is cheap and it solves a lot of different problems mentioned, like how would I turn off the heater in the summer. Just shut off the water valve under the hood and turn AC/Heater blending door to AC. (But instead of using the climate control unit, you're using your hand to manually open and shut the system).

A quick note, when you move the temperature control slider from blue to red, it is connected by cable to both the heater water valve and AC/Heater blending door (it controls both).

DavidCharles

I got my replacement control assembly with cables off E-ay for not too much.


Before you remove the existing assembly make sure you look at each of the four cables to see how they are run. The only one that I still haven't got right is the 'vent' selector cable (upper left knob). Make sure you understand how it runs to the lever on the driver side of the heater box. Take a bunch of pictures.


The other cables are easy to run but make sure you see how they go.