roach_juts

hello

my 1990 300te aux fan stop.. i dont know if its the relay or fuse...
where can i find the fuse & relay ??? so i can check & replace if ever

i drove the car more that a 100 miles today temp today is 90 deg , the temp did not go up it, but as soon i got home i saw my reserve tank is leeking ( easy fix) but i was wondering how come my aux fan is not blowing when the temp is a little bit higher than normal

thanks

Brian_I.

My aux fan(s) never start up that I know of. Is there any easy way to test if it's the fans that are bad or something else? Would changing the thermostat do any good?

epowers777

On my 86 300e the temp sensor went out (green top) it has the aux fan switch built into the temp switch. The fan wouldnt kick on replaced it and it fix lots of problems idling etc. On the 300 te i gota go look at mine. if you kick on ur ac when hot the fan should kick on.

Brian_I.

Would it be this piece...



I'm curious to see if this will help.

If you don't mind me asking, what is the difference in what this does from the actual thermostat?

appatula

That is an electrical sensor that varies its resistance according to temp. This sensor activates the coil on the relay that controls the HIGH speed aux fan setting. The low speed aux setting is activated by a pressure sensor before the A/C drier (activates low fan speed when A/C is on). There is also a resistor inline with the low speed setting located under your ABS unit. The thermostat is a purely mechanical device that valves the coolant according to the temperature. An old timer told me that you can troubleshoot your thermostat by boiling it in a pot of water to see if it opens when the temperature rises.

epowers777

yes that is the part I had to replace. I would first hook you fan up to the battery make sure it didnt die look at the other post it has a detailed explanation on how to do it.

appatula

A much easier approach would be to jump the female 2-pin connector that mates onto the sensor pictured above. This, while the car is on, should activate the relay (a clicking noise) and then power the fan on its high speed. All is needed is a short wire .

Brian_I.

Wow, some great information on this here. Would you mind pointing me in the direction of this piece? I can't locate it in the Star Tek-Info page...

appatula

Brian, on the top of the engines valve cover there are 4 bolts . The sensor is located to the right of the third bolt (start from the oil cap) . It will be approx. (to the right) between the third valve cover bolt and the bolt securing the air filter housing. It will be the only sensor with three pins in the same arrangement as the picture above.

Brian_I.

Thanks! I will give that test a shot so I can see if my aux fans are out.

roach_juts

thank for all the info!!!! very very helpfull