Should this thermistor be plugged in?

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mudking82

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Here is a picture of where it is. Passenger side, above left foot area, to the left of blower motor, on the very bottom. The connector is not plugged in to anything. Heater works fine. AC does not, but PO said it needed recharged. I can't seem to find it in any wiring diagrams either. Does anyone know if this should be plugged in? And if so, where? Cause I can't find any connectors for it either. It is PN 88790-60030 if that helps at all. I am wondering if that piece of the airbox could be from a later model, as this vehicle has been salvaged and lots of stuff replaced. Thanks.
3.webp
 
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Maybe you have a special Russian-spec engine because google that part # and all you get is...this thread and a ton of Russian web pages!
 
Jeremy,

That part number you listed has been superseded by 88790-60080. Maybe that will help in your search.

Also, I am not sure if the 94 and 97 work the same but this should be loose. It should be connected at one end to the vehicle harness but the other is for lack of better words open. I will guess that you have automatic climate control, if not I am stumped. Here is a guess of its use if you do not have ACC. A thermistor works kind of like a thermostat in your house. As temperature increases or decreases it has a different resistance. This type of switch can (and usually is used) to regulate heating and cooling circuits. You can also check it for resistance to ensure it is working within specs, if not you can replace it. I am assuming since you stated the PO said the system needed charged that it is still blowing air just not cold. If this is the case you should check the thermistor and replace it if it is out of spec.

I know this is not a technical or complete answer for your exact situation but it is the best I can provide. Hopefully somone comes along and knows exactly its purpose. If not, I would say it should be open at one end and connected to a harness at the other.

Glen
 
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Brindleboxer said:
That part number you listed has been superseded by 88790-60080. I will guess that you have automatic climate control, if not I am stumped. I am assuming since you stated the PO said the system needed charged that it is still blowing air just not cold. If this is the case you should check the thermistor and replace it if it is out of spec.
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You're right, it has been superseeded to that number. But no, I don't have automatic climate control. Heater and blower motor work fine. Just found out it is also called a "water temperature switch" in the Toyota diagrams. It was used on all the FZJ80's and LX450's. So now I need to figure out where it plugs into, as the connector was not plugged in to anything.
 
Did you work it out?
 
You probably have the blower assembly from a LX450 or newer LC. It is a water temperature switch. I guess that it's purpose is to react to water temperature and switch on the heating only when the heater core is warm.

In LCs with auto climate control it works like this: you start the truck on a cold morning and press the 'auto' button. The heater instead of blowing cold air like stupid, waits until the water in the system is warm enough. You don't have the auto button so you don't need to worry about this cable.
 
That sounds reasonable, been kind of wondering that. And no franku, it is still hanging there cause I don't have anything to plug it into that I know of. It actually just sits in that plastic housing, so maybe it is the auto cut off for the temp. I don't know.
 
I'm currently rehabbing my heater core and have the same question - for those of us without automatic climate control, does part no. 88790-60030 from the original post plug into anything or does it just hang free?

Sensor is located below the heater core, while the plug is located behind the radio.
 
Bump just in case anyone has any insight. I've got a small coolant leak that appears to be coming from this plug's location. Since it's a water temp sensor, I'm guessing that some coolant is supposed to be in this area. However, there doesn't seem to be any kind of gasket or seal. Should there be?
 
I'm changing out my front heater core because of a failure and had a question about the open plug. Basically I couldn't remember unplugging it and there was no harness connection around.

I also surmised that it's intended purpose is for auto climate vehicles and it was part of every build for what ever reason. I have a 1995 which I believe predates auto climate in the 80s.

Also the sensor resides under the core and senses temperature from physically touching the core. So if you see coolant or some redness around the sensor area you have a leak in your core.
 
landtank said:
I'm changing out my front heater core because of a failure and had a question about the open plug. Basically I couldn't remember unplugging it and there was no harness connection around.

I also surmised that it's intended purpose is for auto climate vehicles and it was part of every build for what ever reason. I have a 1995 which I believe predates auto climate in the 80s.

Also the sensor resides under the core and senses temperature from physically touching the core. So if you see coolant or some redness around the sensor area you have a leak in your core.
Click to expand...


Bit of a bump on this thread, mine is /was attached, but ive replaced my heater core with aftermarket, and this thermistor is now separated from the heater core by some foam

Does it have any effect on the A/C

(theats really two questions)
 
Hi, I am in the middle of the odyssey of building a custom harness for my 80, but I want to use the OEM A/C. I ran into the same issue as you guys but I figured out...
The connector on mine looks like this (it is behind the Radio Player, under the radio cooling fan):
1709059883075.webp

According to the Electric Diagram is listed as "A32" and it is called "A/C Water Temp Sensor". << IT IS A SENSOR NOT A SWITCH!!

1709060324721.webp


Regarding the connector... The side of the harness the colors are Grey-Blue (GR-L) and Green (G). According to ToyoDiy, this part # is 88790-60030, and it was used from 08/1992 up to 07/1996. Then the Switch is changed to 88790-60080 which is the one that goes into the engine.

1709059990260.webp


My car is a 96, but originally manufactured on 95. BUT! Mine had the 88790-60080 sensor on the side of the engine so it didn't make sense...
I checked the Electric Diagram and found it as "A/C Water Temp SENSOR":
1709060176650.webp


But this is ONLY part of the Auto A/C diagram, this sensor is not used in the manual A/C diagram.
If you have a lever or push type manual A/C, you can leave this sensor disconnected, it should not affect operation.

Have a nice day
 
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