Hey guys.

I just picked up a 94 T/A, and am having a little bit of a cooling problem.

my question is, will the engine coolant temp sensor cause the fans not to turn on?

i had a 160* stat in it when i got it, and just swapped it out because i dont want to tune the computer, and it was just too cold inside while driving it in the PA winter. so i just installed a stock 180. anyways.

while driving, it would run at about 170-175*. but when i would get to a light, the temp would run up to about 210, sometimes 230-240. Once im moving, it cools down no problem.

So while i swapped T-stats today, i was there checking the fans, and CTS.
When i ohm'd the sensor out i only can get 00.9. that was with the key on and off, and with the engine cold.
I checked the relays and fuses they are all good, and the fans work by jumping the relays.
Now the other thing is the fans dont come on when you turn the A/C on, which as i know, they should.

So would the Engine Coolant Temp Sensor cause the fans not to turn on by themselfs?


thanks


Aaron

 

The stock PCM settings are 1st fan on at 226*F and 2nd fan on at 235*F (or low speed/high speed, depending an when your 94 was built). Is it getting hotter than 226*F?

Are you checking the correct sensor, the one in the water pump housing that feeds the PCM?
With the meter set to what scale? 00.9 seems like an unusual value????

Have you scanned the PCM? There are codes for the doolant temp sensor and for the fan relay faults? Have you checked the fusible link that supplies power to the fans?

 

The sensor i was checking is the one in the front of the water pump, sorry i didnt specify before.

When the 160* was in, it has reached a tad past the line between 210 and 260. so im guessing in the 240 range.
So i am guessing this is perfectly fine.

Although, arent the fans supposed to turn on when you turn the a/c on?
There is no check engine light on. And i have not checked the pcm for codes.
Would it be beneficial to have the stock fan setting set to a lower temp, say 190 on 185 off?
Im sure the setting was set on the ohms setting.

No i have not checked the fusible link to the fan. But i can manually turn the fans on when i jump the relay...ie: take the cover off of one of the relays, and move the contact over so it contacts.

car was built march 1994

Thanks.

Aaron

 

this happend to me to and it was a blown fuse check that

 

all fuses and relays checked out fine.

im going to put a new temp sensor in the w/p and see what happends.
if same thing. i will call the local guy here who has software, and see what we can come up with.


aaron

 

If you measured the resistance of the temp sensor, with the harness connector removed, and it only read 0.9 ohms, you essentially have a complete short in the sensor. On the other hand, if you had the meter set to kOhms, and you got 900 ohms, and the engine was cold, the sensor would be reading a bit high, since that corresponds to about 125*F.

 

thanks.

im putting a new sensor in tomorrow (today, tuesday when ever it is read), and i will give feedback on what i find.

thanks guys.

aaron