Radiator Fan Problems on a 1994 Saturn SL1 SOHC

my radiator fan will not turn on..

it works if I turn on the A/C.. I swaped out the relays too. I peplace
what i belived to be the radiator fan swith (from Dealer) and still did
not work.... if I bridge those two wire the fan wil turn on but i get a
temp light and a low collent light in the dash.. I am not sure whats
wrong and I am starting to think that the computer is messing up.

I ended up placing a wire from ground to the relay in orders to activate
it with a swith inside the car if it gets warm.

any Ideas?

thanksm
Fred

 

You do not mention if you checked the Coolant Temperature Sensor, but this
is what provides the control signal to turn on the fan. Since it works when
you turn on the A/C, this is good and demonstrates that the relay and fan
are working normally. I'd put my money on the CTS or the wiring/connector
to it.

Bob

 

There isn't a "radiator fan switch" on these cars, the fan is controlled by
the ECM based on the coolant temperature sensor, which tends to fail often
on some Saturns. Some cars have two sensors, one for the gauge and one for
the ECM.

Also, when are you expecting it to turn on? It has to be pretty hot..

 

Not untill 95 or 96 was the fan controlled by the ECM..

91-94 is controlled by the coolant temp sensor on the side of the block.
About a 12 dollar part..

If you have a gauge the telp gauge should go up the 3/4 mark before the fan
turns on.

 

It may be more accurate to say that on the older ones, the PCM reads a
separate coolant temp sensor and turns on the fan. The sensor doesn't
really control the fan, as it's not wired to it directly.

Lane [ l a n e @ p a i r . c o m ]

 

Be careful also - you might need a new radiator fan motor.

The brushes in the motor wear out. As they get worn to the end of their
travel, they become intermittent. Depending on when they decide to function
and when they don't, this can make troubleshooting a real pain in the ass.

Given the age of your car, I'd suggest replacing the radiator fan motor
anyway to be sure.

The fan motors ARE wear items!

 

If the fan works, why replace the motor? the original post stated clearly
the fan worked when the A/C was on, but was not coming on by itself...or
from a signal from the coolant temp sensor.

I replace my CTS, but the car still heats up much more than before. I'm
going to track down the wiring set-up next, to see if that's it. $21 CTS
and the thing STILL doesn't work. It was an easy replacement, though. Took
about 15 minutes.

Barry in C'ville

 

I get nervise when the gauge reaches mid point.. I will let it go and see
if it turns on and 3/4.. mabey there is no problem at all, i just have
never seen any car go past the mid piont with out any problems.



Thank you,

Fred
Cpl/USMC

 

As I indicated below, as the fan motor starts to go out, it fails
intermittently. I was pointing this out because it is something else to
consider when troubleshooting this problem.

I also pointed out that the fan motor is a wear item - that means that a fan
motor that is working just fine isn't necessarily 100% good - it could be
99% bad.

And, given the age of the car (a 94), it is quite likely that there isn't
much life left in the fan motor anyway.

So, if the original poster wants to eliminate the (possibly intermittent)
motor as being a possibility of causing the problem, and if he wants to
reset the clock on the fan motor back to zero (so to speak), then replacing
the fan motor wouldn't be a bad idea at all.


the original post stated clearly

 

The fan's controlled by the ECM on all remotely recent GM cars - at some
point they did switch from having a separate sensor for the gauge/warning
light to having that controlled by the ECM too, that's probably what you're
referring to.

 

I'd only worry if it goes into the red (upper 1/8 of the gauge, if I recall
correctly) and stays there. Normal operating temperature is half to 3/4.

Lane [ l a n e @ p a i r . c o m ]

 

The fan will not come on until the gauge is on or near the 3/4 mark.

When I am not using the AC and get in stuck traffic, or going through a slow
fast food drive-thru, I always turn the AC on for about 5 seconds and then
off. Doing that will turn on the radiator fan for about 4 minutes keeping the
car very cool under the hood.

James

 

Mine started to do that and then I found a crack in the plastic part of the
radiator on the driver side. Take a look at the plastic. Good luck.

 

I had a similar problem. The fault was with the the engine coolant sensor
that screws into the block (Is that what you're calling the "switch?"). At
first I had the wrong one. When I started the car the low coolant
indicator was always on. When I went back to NAPA we found that there are
other sensors that may look similar but have different electrical
characteristics (different temp. range???) that work.

R. Garcia