Honda Car Forum

I believe I've got a bad thermo switch/sensor in my 1995 Honda Civic LX. The
radiator fan does not come on when the AC is switched on (though the
compressor fan works okay). I checked the fan relay by putting 12VDC across
the coil and I hear a click, plus I get continuity across the contacts. I've
bent the pins in case the socket connection is bad. Shorting out the
contacts in the fan relay socket causes the fan to come on, so the fan
itself is okay. That's the disgnostic work I've done so far.

Thanks to Tegger's FAQ, I've been able to locate the thermo switch, but I
cannot figure out how to remove the connector for testing purposes. It's
rotated in such a way that I can't see do undo the connector, and help here?

Aside from the connector, are there any pitfalls I should know about when
replace the thermo switch? It's fairly easy to get to, so I should be able
to do it myself.

Also would like to change the thermostat, but never having done that I need
some assistance. First, in locating it. Then in determine what type it is
(med temp/high temp) and removal procedure. I've read that on later model
Honda's it's on the lower radiator hose but I can't see it.

"DesignGuy" <dontbother@nowhere.com> wrote in
news:PH8Qd.70$tl3.28@attbi_s02:

> I believe I've got a bad thermo switch/sensor in my 1995 Honda Civic
> LX. The radiator fan does not come on when the AC is switched on
> (though the compressor fan works okay). I checked the fan relay by
> putting 12VDC across the coil and I hear a click, plus I get
> continuity across the contacts. I've bent the pins in case the socket
> connection is bad. Shorting out the contacts in the fan relay socket
> causes the fan to come on, so the fan itself is okay. That's the
> disgnostic work I've done so far.



Does the rad fan come on when the engine has been in heavy traffic for 5
minutes?

Warm it up all the way, take it to a quiet side street somewhere, and then
simulate heavy stop-and-go "inch forward" traffic for 5 minutes. If your
fan is not coming on, the temp gauge will begin to rise.


>
> Thanks to Tegger's FAQ, I've been able to locate the thermo switch,
> but I cannot figure out how to remove the connector for testing
> purposes. It's rotated in such a way that I can't see do undo the
> connector, and help here?
>
> Aside from the connector, are there any pitfalls I should know about
> when replace the thermo switch? It's fairly easy to get to, so I
> should be able to do it myself.
>
> Also would like to change the thermostat, but never having done that I
> need some assistance. First, in locating it. Then in determine what
> type it is (med temp/high temp) and removal procedure. I've read that
> on later model Honda's it's on the lower radiator hose but I can't see
> it.



The thermostat is at the TOP of the engine, where the heat goes. The lower
hose is a long, snaky thing that goes from the bottom of the rad to the
thermostat housing. Follow the hose from the rad to the other end and there
it is.

WORD OF WARNING:
DO NOT INSTALL AN AFTERMARKET THERMOSTAT. Those things are much too likely
to cause you no end of grief. An OEM (and gasket) is less than $20.

There is only one rating of OEM: 90C/194F. DO NOT install a cooler one!

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

>
> The thermostat is at the TOP of the engine, where the heat goes. The lower
> hose is a long, snaky thing that goes from the bottom of the rad to the
> thermostat housing. Follow the hose from the rad to the other end and
there
> it is.
>
> WORD OF WARNING:
> DO NOT INSTALL AN AFTERMARKET THERMOSTAT. Those things are much too likely
> to cause you no end of grief. An OEM (and gasket) is less than $20.
>
> There is only one rating of OEM: 90C/194F. DO NOT install a cooler one!


I'm confused. I was thinking that was the thermo switch/sensor, since it
labeled such on the FAQ:
http://www.tegger.com/hondafaq/overh...ndex/index.htm
(photo next to "Thermo Sensor Check")

Are the thermo sensor/thermostat one and the same?

Also, tnx for the tip on using an OEM part, I'll be sure to do that.

>
> Does the rad fan come on when the engine has been in heavy traffic for 5
> minutes?
>
> Warm it up all the way, take it to a quiet side street somewhere, and then
> simulate heavy stop-and-go "inch forward" traffic for 5 minutes. If your
> fan is not coming on, the temp gauge will begin to rise.

I forgot to answer this part -- no the rad fan does not come on, whether
driving at speed for a while or stop-and-go. The temp guage doesn't rise to
much, no more than 1/3 of the way up.

Incorrect,

my Acura Vigor price for the thermostat was 86$ sale price, 110$ regular
price. Plus 11$ for gasket!

15$ at Canadian Tire... I still bought the OEM.

Adrian


"TeGGer®" <tegger@istop.c0m> wrote in message
news:Xns95FDAEB1818Eteggeratistop@207.14.113.17...
> "DesignGuy" <dontbother@nowhere.com> wrote in
> news:PH8Qd.70$tl3.28@attbi_s02:
>
>> I believe I've got a bad thermo switch/sensor in my 1995 Honda Civic
>> LX. The radiator fan does not come on when the AC is switched on
>> (though the compressor fan works okay). I checked the fan relay by
>> putting 12VDC across the coil and I hear a click, plus I get
>> continuity across the contacts. I've bent the pins in case the socket
>> connection is bad. Shorting out the contacts in the fan relay socket
>> causes the fan to come on, so the fan itself is okay. That's the
>> disgnostic work I've done so far.
>
>
>
> Does the rad fan come on when the engine has been in heavy traffic for 5
> minutes?
>
> Warm it up all the way, take it to a quiet side street somewhere, and then
> simulate heavy stop-and-go "inch forward" traffic for 5 minutes. If your
> fan is not coming on, the temp gauge will begin to rise.
>
>
>>
>> Thanks to Tegger's FAQ, I've been able to locate the thermo switch,
>> but I cannot figure out how to remove the connector for testing
>> purposes. It's rotated in such a way that I can't see do undo the
>> connector, and help here?
>>
>> Aside from the connector, are there any pitfalls I should know about
>> when replace the thermo switch? It's fairly easy to get to, so I
>> should be able to do it myself.
>>
>> Also would like to change the thermostat, but never having done that I
>> need some assistance. First, in locating it. Then in determine what
>> type it is (med temp/high temp) and removal procedure. I've read that
>> on later model Honda's it's on the lower radiator hose but I can't see
>> it.
>
>
>
> The thermostat is at the TOP of the engine, where the heat goes. The lower
> hose is a long, snaky thing that goes from the bottom of the rad to the
> thermostat housing. Follow the hose from the rad to the other end and
> there
> it is.
>
> WORD OF WARNING:
> DO NOT INSTALL AN AFTERMARKET THERMOSTAT. Those things are much too likely
> to cause you no end of grief. An OEM (and gasket) is less than $20.
>
> There is only one rating of OEM: 90C/194F. DO NOT install a cooler one!
>
> --
> TeGGeR®
>
> The Unofficial Honda/Acura FAQ
> www.tegger.com/hondafaq/

DesignGuy wrote:
> I believe I've got a bad thermo switch/sensor in my 1995 Honda Civic
LX. The
> radiator fan does not come on when the AC is switched on (though the
> compressor fan works okay). I checked the fan relay by putting 12VDC
across
> the coil and I hear a click, plus I get continuity across the
contacts. I've
> bent the pins in case the socket connection is bad. Shorting out the
> contacts in the fan relay socket causes the fan to come on, so the
fan
> itself is okay. That's the disgnostic work I've done so far.
>
> Thanks to Tegger's FAQ, I've been able to locate the thermo switch,
but I
> cannot figure out how to remove the connector for testing purposes.
It's
> rotated in such a way that I can't see do undo the connector, and
help here?
>
> Aside from the connector, are there any pitfalls I should know about
when
> replace the thermo switch? It's fairly easy to get to, so I should be
able
> to do it myself.
>
> Also would like to change the thermostat, but never having done that
I need
> some assistance. First, in locating it. Then in determine what type
it is
> (med temp/high temp) and removal procedure. I've read that on later
model
> Honda's it's on the lower radiator hose but I can't see it.

The connector to the thermo switch has "lock" that must be raised about
1/16 of an inch before it can be unpluged. You may have to back the
thermo
switch a quarter turn or so to get to this "lock". The thermostat is a
couple
of inches to the right of the thermo switch an a bit higher. Be aware
that
there is still antifreeze in this part of the engine even after you
drain
the radiator. See Tegger's FAQ under radiator does not come on by
REMCO
for a lot of good data.
Ernie

"Nightdude" <nightdude@rogers.com> wrote in
news:AO9Qd.2016$dZ.165174@news20.bellglobal.com:

> Incorrect,
>
> my Acura Vigor price for the thermostat was 86$ sale price, 110$
> regular price. Plus 11$ for gasket!


Whooooa! Mine was $12 at the dealer. I've NEVER bought an OEM thermostat
for any make that was more than $20. Maybe I'm buying the wrong cars.


>
> 15$ at Canadian Tire... I still bought the OEM.


You won't regret it.


--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"DesignGuy" <dontbother@nowhere.com> wrote in
news:sL9Qd.1522$4q6.638@attbi_s01:

>

>
> I'm confused. I was thinking that was the thermo switch/sensor, since
> it labeled such on the FAQ:
> http://www.tegger.com/hondafaq/overh...ndex/index.htm
> (photo next to "Thermo Sensor Check")
>
> Are the thermo sensor/thermostat one and the same?


No. The thermostat is a big round mechanical thing about 2" in diameter.
It's inserted into the coolant stream and is supposed to block coolant flow
until a proper temperature is reached. The only way to change it is to
drain the coolant and remove the thermostat housing.

http://tegger.com/hondafaq/misc/thermostat.jpg

All the other things are electronic and serve to turn fans on and such.
They might tap into the coolant stream so they can sense the temperature,
but you can usually change them without draining the coolant.



--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"DesignGuy" <dontbother@nowhere.com> wrote in
news:dN9Qd.68973$eT5.23856@attbi_s51:

>>
>> Does the rad fan come on when the engine has been in heavy traffic
>> for 5 minutes?
>>
>> Warm it up all the way, take it to a quiet side street somewhere, and
>> then simulate heavy stop-and-go "inch forward" traffic for 5 minutes.
>> If your fan is not coming on, the temp gauge will begin to rise.
>
> I forgot to answer this part -- no the rad fan does not come on,
> whether driving at speed for a while or stop-and-go. The temp guage
> doesn't rise to much, no more than 1/3 of the way up.
>
>
>
>


Sounds like your thermostat may be going bad. You should be up to just
below the half-way mark on the gauge in less than ten minutes of driving.

How's your heater output?

The rad fan will NOT come on until the coolant temperature is high enough
to close the contacts in the fan switch. You may never be getting there.

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

DesignGuy wrote:
> >
> > The thermostat is at the TOP of the engine, where the heat goes.
The lower
> > hose is a long, snaky thing that goes from the bottom of the rad to
the
> > thermostat housing. Follow the hose from the rad to the other end
and
> there
> > it is.
> >
> > WORD OF WARNING:
> > DO NOT INSTALL AN AFTERMARKET THERMOSTAT. Those things are much too
likely
> > to cause you no end of grief. An OEM (and gasket) is less than $20.
> >
> > There is only one rating of OEM: 90C/194F. DO NOT install a cooler
one!
>
>
> I'm confused. I was thinking that was the thermo switch/sensor, since
it
> labeled such on the FAQ:
>
http://www.tegger.com/hondafaq/overh...ndex/index.htm
> (photo next to "Thermo Sensor Check")
>
> Are the thermo sensor/thermostat one and the same?
>
> Also, tnx for the tip on using an OEM part, I'll be sure to do that.

DG, in your post refering to the photo in "Thermo Sensor Check"
The brass colored Sensor is the Thermo Switch. The wires under the
bolt to the right are ground wires. The bolt there holds the cover
to the thermostat, the hose on the right side of the picture is the
lower radiator hose. Remove this hose and another bolt(or two) and
the cover for the thermostat comes off.