BJ70 heater super slooooooooow

[NV BJ70]

So the BJ70 has another problem...
the heater is super duper extremely slow at making the truck warm...

Even when i've started up the engine and let it warm up for awhile, the heat is still cold when i've got the max heat on. There was one time that i had it idling for 45 mins (cuz i was busy helping my dad) and when i started driving... THE HEAT WAS STILL FREEZING COLD

Basically it only warms up significantly after i've been actually driving it (like RPMs at 1500-2000s), such as hwy driving

My dad suggests that the water temp thermostat is sticky and not actually opening a valve that will actually get the cooling system to operate, and in turn warm up the heater.

Also, No.1 fan speed does not work at all. I've tried it a million times and nothing. When i've had the engine off, i tried to turn the switch slowly to reduce the clicking noise to see if i could hear anything. I did hear some sort of relay or something clicking inside, but the fan doesn't turn on at No.1 speed... only works at positions of 2,3,4...

thanks in advance

 

[Estancio]

Fan speed is controlled by a resistor. Most likely that is the fan speed problem, not the switch itself.

As for your no heat situation, could be any number of things that are interferring with the flow of hot coolant to your heater core. Core itself, thermostat, valves, hoses, lack of coolant. Your dad's suggestion to check the thermostat is a good place to start the search....

 

[Estancio]

Here is a parts diagram to show the location of the resistor for my 1987 BJ70 which is 24Volt. Yours should be similar - but will be 12volt as I recall....

 

[roscoFJ73]

If the heater core is blocked,disconnect the hoses going into the firewall and back flush with the garden hose.You will often get a big rush of dirty sediment out of it.
And you dad is correct about checking the tstat.

The resistor on number 1 speed is a common point to fail on many vehicles and landcruisers are bad for it.

 

[Estancio]

Checked the part number for your 1985 12volt.
Your part number is #87138-90K00

 

[Gun Runner 5]

If the heater core is blocked,disconnect the hoses going into the firewall and back flush with the garden hose.You will often get a big rush of dirty sediment out of it.
And you dad is correct about checking the tstat.

The resistor on number 1 speed is a common point to fail on many vehicles and landcruisers are bad for it.

Good advise but I would go one step further and back flush MULTIPLE times. It took me 3 times to fully remove the crud.
The first fan setting was also bad on my LJ78 while the rest worked normally.

 

[NV BJ70]

If the heater core is blocked,disconnect the hoses going into the firewall and back flush with the garden hose.You will often get a big rush of dirty sediment out of it.
And you dad is correct about checking the tstat.

The resistor on number 1 speed is a common point to fail on many vehicles and landcruisers are bad for it.

I will try the flushing first!

Checked the part number for your 1985 12volt.
Your part number is #87138-90K00

Thank you very much will go to the dealer and see about it!

Good advise but I would go one step further and back flush MULTIPLE times. It took me 3 times to fully remove the crud.
The first fan setting was also bad on my LJ78 while the rest worked normally.

Thanks

 

[Radd Cruisers]

We have the heater blower resistors in stock for the 12V and 24V BJ7x models.

Sometimes shops mistakenly install a 2F thermostat into the 3B (for some reason parts searches at places like Lordco and Napa and others will come up with the wrong unit).

The 3B unit is quite different than the 2F unit. If the wrong one is installed, you will not get heat.

~John

 

[Estancio]

Hey, NV BJ70, here is another suggestion if you are opening up the blower unit to install a new resistor. I suggest you open up the blower/fan unit and check the condition of the fan motor brushes. I have replaced these before and it is not so difficult. On your 27-year old BJ70, they might be due for replacement.

Also, I recommend that you lubricate the motor bearings/bushings while you are in there. I always use synthetic grease. To do this, you would need to disassemble the blower unit completely. My first BJ blower died from lack of lube - which I decided had put a strain on other parts and was responsible for dead resistor and worn out motor. On my current BJ70, I open it up and lube it every 5 years or so and still have all original parts in perfect working order. A little maintenance goes a long way to keep parts moving.

 

[jetswim]

My BJ74 will only produce heat after driving for awhile. Idling never seems to warm it up. My T-stat seems to be fine. I just chalked it up to an efficient cooling system. Once the heat is there it's toasty but it takes fifteen or twenty minutes of driving.

 

[NV BJ70]

thanks you guys all

sorry i havent really been on here for awhile but here's the rundown of what i did to fix the slow heat problem
i called the toyota dealership and ordered a new thermostat (plus gasket) i think it cost about $62.
i spent half the day trying to take off the bolts because one was strangely tight the whole way coming out.
then i put the new thermostat in, bolted it all back up, put the hoses back on, and VOILA heat!!!!

havent done anything with the fan speed yet but, yeah, i have heat now

The weird thing is that the temp gauge jumps straight to the top right away when i turn the key to "ON". I dont remember when it started, but it was doing it before i changed the thermostat and still is now.

 

[jb BJ73]

The gauge is obviously doing this when the engines cold? It's probably a faulty sensor that is shorting to ground.

 

[Radd Cruisers]

If the sensor wire is grounded, the gauge will read full hot. Check for a bad connection at the sensor where the wire may have gone to ground. Then, check the sensor for its resistance value and see if it's shagged (fairly likely). The temp sensor is common to a number of models and should be easy to get.


~John

 

[NV BJ70]

is it the one with the green plastic plug?

 

[Gun Runner 5]

Had the same issue ..... Traced it to a bad "ground" wire.