A/C & Radiator fan not working

Recently my 1996 SC1 began to get hot in heavy traffic. Normally the
radiator fan will come on when the A/C is on or if the temp gauge reaches
1/2 way. In this case neither happened. In testing the components both the
fan and the A/C compressor work when 12v is applied directly to them. The
car has a single coolant temp sensor so the temp gauge would not work if the
coolant tem sensor was bad. No trouble codes from the computer and the fuses
and relays are all good. Any ideas would be appreciated.

mike

 

Relay(s) maybe.

 

see topic "cooling fan" Nov 27

 

Tried the relays.so all work OK.

 

Yes, I read that first. Thanks

 

Oh oops I missed that in your post. Might have to start tracing your
power source up the line. Just have to make sure its commanded on. ECM
maybe... <i'm half asleep here...>

 

"The car has a single coolant temp sensor so the temp gauge would not
work if the coolant tem sensor was bad."

This is not true. If you have never changed the CTS, change it to see
if your problem is solved. The original design CTS was made of resin,
which cracked due to the high heat of the coolant. The new, replacement
OE part is made of brass for durability. If the sensor is cracked, it
will not read the correct coolant temp (in your case, lower than it
really is) and the PCM will not command the fan on.
A bad CTS doesn't always set a DTC, either.

 

The temperature guage will still operate on the IP cluster if the
sensor is bad.

You're headed in the right direction, though. RE: The ECTS (engine
coolant temperature sensor). The original part was made of resin, which
cracked due to the high temperature of the coolant passing over it. The
new, redesigned OE part is made of brass for durability and to correct
this issue. If you replace it (I would, if you never have... $10 in
parts) be sure the contacts on the connector are clean.

Hopefully this won't be a double-post. The first time I tried, it
didn't show? New to this group.