I'm not sure if this is common with these old Tercels.
I find my radiator fan comes on a bit too late compared to my coolant temp, and doesn't really stay on long enough.
What could I do to adjust the point at which the radiator fans comes on and turns off without manually turning it on or off?
This is the only cooling problem I have left to sort out with my wagon. I have just recently replace the water pump, thermostat, radiator, and done fresh coolant. All of this already has made a big difference compared to when I first the car.
The radiator fan issue I described only really happens when the car has been idling for a bit.
Radiator fan adjustments?
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Kozuto_98
- Top Notch Member
- Posts: 229
- Joined: Fri Jun 26, 2020 3:45 pm
- My tercel:: 1987 SR5 Wagon
- Location: Nova Scotia, Canada
Radiator fan adjustments?
1987 Tercel Wagon SR5 4WD
1998 Honda Accord Coupe V6 J35 swap
1997 Acura CL (Sold for 4A-GE money)
RIP 2016 Civic (wrist pin recall)
1998 Honda Accord Coupe V6 J35 swap
1997 Acura CL (Sold for 4A-GE money)
RIP 2016 Civic (wrist pin recall)
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ALiveSR5
- Top Notch Member
- Posts: 164
- Joined: Fri Sep 18, 2020 7:58 pm
- My tercel:: Was a stock 1985, SR5, 4WD, 6-speed manual, Wagon.
- Location: Pennsylvania USA
Re: Radiator fan adjustments?
Could it be the temperature sensor at the bottom of the radiator going bad?
No other vehicle that I have ever owned had a heart and soul like my 1985 Tercel SR5 4WD Wagon. 
~
Great minds may think alike but it is the doers who see their visions become reality.
~
Great minds may think alike but it is the doers who see their visions become reality.
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Kozuto_98
- Top Notch Member
- Posts: 229
- Joined: Fri Jun 26, 2020 3:45 pm
- My tercel:: 1987 SR5 Wagon
- Location: Nova Scotia, Canada
Re: Radiator fan adjustments?
It's certainly a possibility, but it still seems to work fine. I'm mainly looking for a method to turn the fan on earlier and to stay on a bit longerALiveSR5 wrote: Wed Oct 21, 2020 7:21 pm Could it be the temperature sensor at the bottom of the radiator going bad?
than it currently does.
1987 Tercel Wagon SR5 4WD
1998 Honda Accord Coupe V6 J35 swap
1997 Acura CL (Sold for 4A-GE money)
RIP 2016 Civic (wrist pin recall)
1998 Honda Accord Coupe V6 J35 swap
1997 Acura CL (Sold for 4A-GE money)
RIP 2016 Civic (wrist pin recall)
Re: Radiator fan adjustments?
I would consider replacing the sending unit mentioned. They may even have something with a lower switch point. If you are just watching the guage, I would slso suggest a temp measurement to confirm what the guage roughly indicates.
Psalm 37:4 "Delight yourself in the Lord and he will give you the desires of your heart"
In remembrance of my friend ARCHINSTL:
T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
In remembrance of my friend ARCHINSTL:
T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
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Kozuto_98
- Top Notch Member
- Posts: 229
- Joined: Fri Jun 26, 2020 3:45 pm
- My tercel:: 1987 SR5 Wagon
- Location: Nova Scotia, Canada
Re: Radiator fan adjustments?
Alrighty! I'll give that a try.NWMO wrote: Wed Oct 21, 2020 9:35 pm I would consider replacing the sending unit mentioned. They may even have something with a lower switch point. If you are just watching the guage, I would slso suggest a temp measurement to confirm what the guage roughly indicates.
1987 Tercel Wagon SR5 4WD
1998 Honda Accord Coupe V6 J35 swap
1997 Acura CL (Sold for 4A-GE money)
RIP 2016 Civic (wrist pin recall)
1998 Honda Accord Coupe V6 J35 swap
1997 Acura CL (Sold for 4A-GE money)
RIP 2016 Civic (wrist pin recall)
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Petros
- Highest Ranking Member
- Posts: 11941
- Joined: Sun Jan 28, 2007 6:31 pm
- My tercel:: '84 Tercel4wd w/extensive mods
- Location: Arlington WA USA
Re: Radiator fan adjustments?
there is no adjustment, it is controlled by the sensor. could be the sensor going bad. they do not cost much. I would check out the actual on/off temps as specified in the FSM, and replace it if it is out of spec.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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Fadebraham
- Newbie
- Posts: 6
- Joined: Thu May 29, 2025 10:50 am
- My tercel:: 86 tercel base model
Re: Radiator fan adjustments?
I am having the same issues with my 86 dlx. The car runs great drives great. I switched the thermostat and the sensor underneath the rad. But when I’m stopped at a light it warms up until the fan kicks in which is also too late. Did you find a solution ?
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dlb
- Highest Ranking Member
- Posts: 7446
- Joined: Mon Jul 06, 2009 9:03 pm
- My tercel:: '87 sr5, '83 dlx parts car
- Location: bc, canada
Re: Radiator fan adjustments?
What temperature is the t-stat you put in? My tercel always ran hotter than I was comfortable with (between 1/2 to 2/3 on the gauge) and it finally blew the head gasket last xmas. I replaced the head gasket but the temp still ran in the same range so I swapped in a cooler t-stat. Now it runs where I like it (between 1/3 to 1/2 on the gauge). This wouldn't solve you issue of the fan coming on too late for your liking but it would help keep the temp away from needing the fan.
Only other solutions I can think of are finding a rad fan sensor with a lower 'on' temp (which I've never heard of but seems likely to exist), or wiring in a manual override fan switch.
Only other solutions I can think of are finding a rad fan sensor with a lower 'on' temp (which I've never heard of but seems likely to exist), or wiring in a manual override fan switch.