92 Caravan A/C & Radiator fan problems

Both fans & A/C clutch don't work. All will work when I put a 12 v source
to them, but won't work otherwise. I have checked the power past the
fuseable link at the battery, and have power, but no power at the relays.
I have a parts car and have change out the relays, but that didn't help.

How do you check the relays for operation, and is there some other fuses
or fusable links that I haven't found that I can check or replace.

Any ideas would be appreciated.

"remlap" > wrote in message
lkaboutautos.com...
> Both fans & A/C clutch don't work. All will work when I put a 12 v source
> to them, but won't work otherwise. I have checked the power past the
> fuseable link at the battery, and have power, but no power at the relays.
> I have a parts car and have change out the relays, but that didn't help.
>
> How do you check the relays for operation, and is there some other fuses
> or fusable links that I haven't found that I can check or replace.
>
> Any ideas would be appreciated.
>
>

Sometimes the fusible link will partially fail so you still get 12V with no
load but then the fans run slow or not at all. Check the voltage after the
link while the load is on. This happened to me and it took a while for me
to figure out...

--
Scott Ehardt
http://www.scehardt.com

"remlap" > wrote in message
lkaboutautos.com...
> Both fans & A/C clutch don't work. All will work when I put a 12 v source
> to them, but won't work otherwise. I have checked the power past the
> fuseable link at the battery, and have power, but no power at the relays.
> I have a parts car and have change out the relays, but that didn't help.
>
> How do you check the relays for operation, and is there some other fuses
> or fusable links that I haven't found that I can check or replace.
>
> Any ideas would be appreciated.
>
>

Sometimes the fusible link will partially fail so you still get 12V with no
load but then the fans run slow or not at all. Check the voltage after the
link while the load is on. This happened to me and it took a while for me
to figure out...

--
Scott Ehardt
http://www.scehardt.com

This was my advice for another person with radiator cooling problem only.
There is also a sensor/switch for the a/c fan located in behind grill along
with radiator sensor.

a/c clutch activation is usually dependent on adequate freon pressure so you
might check that first. This prevents compressor damage.

Good luck


1. Thermostat was a good start and really does not matter where you
purchase the item. If you really need to feel it works then test the
activation point slowly boil a pot of water on the stove and hang a cooking
thermometer on the side. Your real problem as described appears to be your
radiator fan is not activating at the appropriate time. Check to see if it
is working by warming up the engine and letting idle until it reaches normal
or slightly higher temp. If the radiator fan does not activate above your
normal reading or at all then check that the electrical connections are
clean etc. You can also apply 12v directly to the fan motor leads (while
car is off) to verify the fan motor is working. If connection and fan are
ok then your likely problem is the electronic temperature sensor/switch for
your radiator cooling fan or the relay that supports it. Relay is part of a
three/four relay group mounted to the inside of driver front fender (next to
battery) It should click everytime the fan turns on/off. If the relay is
fine then replace electronic temperature sensor/switch for your radiator
cooling fan. It is behind your grill and is usually mounted to the center
brace. It measures both the incoming air and the radiant temp of the
radiator and turns the fan on (using the relay) as needed. The
sensor/switch fails over time or can break loose from its mount (plastic tab
used) and is simple to change. Relay is std part you can get anywhere.
Sensor is a dealer only part, remove the old one and take it to the dealer
so they can order the part.
"Scott Ehardt" > wrote in message
news
> "remlap" > wrote in message
> lkaboutautos.com...
> > Both fans & A/C clutch don't work. All will work when I put a 12 v
source
> > to them, but won't work otherwise. I have checked the power past the
> > fuseable link at the battery, and have power, but no power at the
relays.
> > I have a parts car and have change out the relays, but that didn't help.
> >
> > How do you check the relays for operation, and is there some other fuses
> > or fusable links that I haven't found that I can check or replace.
> >
> > Any ideas would be appreciated.
> >
> >
>
> Sometimes the fusible link will partially fail so you still get 12V with
no
> load but then the fans run slow or not at all. Check the voltage after
the
> link while the load is on. This happened to me and it took a while for me
> to figure out...
>
> --
> Scott Ehardt
> http://www.scehardt.com
>
>

This was my advice for another person with radiator cooling problem only.
There is also a sensor/switch for the a/c fan located in behind grill along
with radiator sensor.

a/c clutch activation is usually dependent on adequate freon pressure so you
might check that first. This prevents compressor damage.

Good luck


1. Thermostat was a good start and really does not matter where you
purchase the item. If you really need to feel it works then test the
activation point slowly boil a pot of water on the stove and hang a cooking
thermometer on the side. Your real problem as described appears to be your
radiator fan is not activating at the appropriate time. Check to see if it
is working by warming up the engine and letting idle until it reaches normal
or slightly higher temp. If the radiator fan does not activate above your
normal reading or at all then check that the electrical connections are
clean etc. You can also apply 12v directly to the fan motor leads (while
car is off) to verify the fan motor is working. If connection and fan are
ok then your likely problem is the electronic temperature sensor/switch for
your radiator cooling fan or the relay that supports it. Relay is part of a
three/four relay group mounted to the inside of driver front fender (next to
battery) It should click everytime the fan turns on/off. If the relay is
fine then replace electronic temperature sensor/switch for your radiator
cooling fan. It is behind your grill and is usually mounted to the center
brace. It measures both the incoming air and the radiant temp of the
radiator and turns the fan on (using the relay) as needed. The
sensor/switch fails over time or can break loose from its mount (plastic tab
used) and is simple to change. Relay is std part you can get anywhere.
Sensor is a dealer only part, remove the old one and take it to the dealer
so they can order the part.
"Scott Ehardt" > wrote in message
news
> "remlap" > wrote in message
> lkaboutautos.com...
> > Both fans & A/C clutch don't work. All will work when I put a 12 v
source
> > to them, but won't work otherwise. I have checked the power past the
> > fuseable link at the battery, and have power, but no power at the
relays.
> > I have a parts car and have change out the relays, but that didn't help.
> >
> > How do you check the relays for operation, and is there some other fuses
> > or fusable links that I haven't found that I can check or replace.
> >
> > Any ideas would be appreciated.
> >
> >
>
> Sometimes the fusible link will partially fail so you still get 12V with
no
> load but then the fans run slow or not at all. Check the voltage after
the
> link while the load is on. This happened to me and it took a while for me
> to figure out...
>
> --
> Scott Ehardt
> http://www.scehardt.com
>
>