Heater fan intermittant

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tercle
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Joined: Sat Aug 27, 2011 9:57 am
My tercel:: 1985 SR5
Location: Seattle

Heater fan intermittant

Post by tercle »

This just seemed to start happening about when it got cold.
Usually, the fan works. Sometimes my feet get really cold and I realize the fan stopped working. Then I turn it off and on - nothing.
Put it on the Medium setting instead of High - nothing.
Later, after parking, the fan works.
Everything else electrical seems to be working.
What do you think it is?
Ground, switch, fan motor?
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rer233
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My tercel:: Multiple

Re: Heater fan intermittant

Post by rer233 »

had the same problem with a former GF's car years back. naturally every time i had the car, the fan worked perfectly! wound up wiring an indicator bulb to the blower motor wires and told her to look at the bulb next time the blower's inop. turned out to be the motor itself --not a bad job to change. hope this helps!
if it aint there, there's a good chance it won't break!
83 SR5 Silver/Blue (Snowmobile/work beater)-totaled but drivable
85 SR5 Blue
88 SR5 White (the 'good' one)-not anymore-totaled
87 fwd silver wagon a/t
87 4wd dx Cream (a/t- not anymore- now m/t)
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Heater fan intermittant

Post by Petros »

sounds like something is marginal, when cold it works than it warms up and fails. could be the resistor or the motor. The resistor and motor both are common to all of the same style Tercels across the years ('83-86 2wd and '83-88 4wd), so it should be fairly easy to find used replacements. I also think Rockauto sells blower motors for the Tercel as well.
'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)
tercle
Top Notch Member
Posts: 222
Joined: Sat Aug 27, 2011 9:57 am
My tercel:: 1985 SR5
Location: Seattle

Re: Heater fan intermittant

Post by tercle »

I think it was the blower relay.
I swapped blower relays with my old blue 86 wagon on Saturday, and over two days the fan motor has worked every time.
If I can go through the whole week, I will consider it fixed.

On the 86, it is behind and a little below the right speaker.
I thought the manual indicated it was behind the kick panel, but it is behind the passenger speaker cover.
tercle
Top Notch Member
Posts: 222
Joined: Sat Aug 27, 2011 9:57 am
My tercel:: 1985 SR5
Location: Seattle

Re: Heater fan intermittant

Post by tercle »

It was the blower motor, after all.
The problem came back after I replaced the relay.

I noticed something that may have contributed to the old motor's troubles.
There is a pleated rubber hose that goes from the motor to the fan plenum or chamber.
A previous owner had a tie-wrap strapping some wires to it.
The tie-wrap was cinched pretty tight and the hose was practically pinched off.
So the motor wasn't getting the ventilation and cooling that it was supposed to.
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ARCHINSTL
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My tercel:: Goldie is a 1986 SR5 attualmente con Weber/also owned the first T4WD in STL in late '82
Location: Kirkwood, a 'burb of St. Louis

Re: Heater fan intermittant

Post by ARCHINSTL »

So that's what that little hose is for! I wondered - but electrical thingies, whether wires or appendages, are always a mystery.
Tom M.
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