Overheating......Radiator Fan Not running... Help

[3rdOne]

Great forum...by the way!!

93 Ply Grand Voyager SE 3.3L V6
Drove about 10 miles yesterday van ran fine. Stopped in a parking lot left van running. Check gauge light came on. Van was overheating. Coolant level was fine. Radiator fan would not run. Drove it back home temperature gauge stayed were it always did on drive home. Left it running in driveway it began to overheat. Checked fan it is operational just won't kick on.

Any advice???

A/C compressor stopped running a couple weeks ago could they be related problems? Relays Prehaps??

[Magus 357]

I am having the same issues and I can not figure it out.

I replaced the thermostat.
I tried to replace the fan, thinking it was bad, recieved the same results so I took the $200 fan back.

Now I am going to try to replace the sensor.

[3rdOne]

At least I am not alone. If we could just figure out the problem.

To bring you up to date on mine: we bought a new coolant temperature sensor and tried it, but it did not solve the problem.

We were stumped so we ran a wire from radiator fan to battery. Fan would kick in and we could watch the temperature gauge drop as fan ran.

Since we didn't know what to do next we improvised. We spliced radiator fan wire, ran that to battery, then to a toggle switch inside van.
I've drove with it for about a week now. As long as I am driving the temp gauge is fine. When I am idleing I keep an eye on gauge if it starts to rise I flip the toggle switch for the fan. So far this has worked great. I just have to remember to flip it off. Although a more permanent solution would be better. If you find out anything please pass it on, as will I.

Someone suggested the radiator fan relay. I checked on one it runs $24.99 So if I have the extra cash I will try it this weekend. If not next.

Keep me posted on your progress.

[Magus 357]

Well, I spent $13 dollars for the sensor and as you know, this did not work. I did buy a book called "sure you can" "work on electronic ignition"
Its by a company called Wells. You purchase a key that you can supposedly plug into a spot to get all of the service codes for your car. This should give me a better ballpark as to what is wrong with my car. I will try it and keep everyone posted.

My major problem is I dont know where to plug the d@#! thing in.

[Bigjohnjr]

I am having the same problem with a 93 with the 3.3
I changed the fan, changed both relays, temp sensor, etc...

I ran a switch to the dash board to turn the fan on and off as needed.

I just orded a universal temp sensor from Jegs (16.99).

When it comes in I will mount it and use a realy to turn the fan on and off. The temp sensor is rated at 170f.

I will keep you posted.

Oh yea I also stoped by a Chrysler dealer and asked him about it and he was lost on why it did not work but for $85.00 per hour they would look at it. No thanks!

[Bigjohnjr]

As many of you know by now is that the cooling fan is not just a simple circuit.

First the fan is a 2 speed fan, low and high (I don't know why)

Low is for normal cooling of the radator.

High is for when the a/c is on, or the transmison calls for high cooling ( why the trans is any ones guess)

So there are 2 relays, low and high, and somewhere else there is a fan switch.

The fan switch is mounted unknow by me or the 3 places I went to.

The fan has 4 wires on it. Ground, low, high, and unknow.

The unkown wire might be a feedback wire.

As far as I can tell the temp sensor tells the temp gauge what the temp is and also tells the power train controll what temp the engine is at.

At that point the power train controll will either select low or high.

I have taken 2 fans and applied 12 volts to the low and the fan did not spin at all. If I put 12 volts on the high the fan runs.

If I put 12 volts on that yellow wire I get sparks.

Why did chrylser make a simple fan so complacted I do not know.

All this about the fan I figured out myself, if I am wrong on how it works please correct me.

I have spent many hours working on this fan curcuit and many phone calls to the local dealer ( that was little help at all ).

I have had other cars that the fan stoped working and they were no where this complated.

So for know I am using a toggle switch for the fan. I did order a temp sensor and will hook that up for the fan using a relay. A simple circiut using just the high speed and nothing else, just the way it should be.

Thanks
John

[Magus 357]

So for know I am using a toggle switch for the fan. I did order a temp sensor and will hook that up for the fan using a relay. A simple circiut using just the high speed and nothing else, just the way it should be.

Thanks
John[/quote]

Hey John,

Which wire to the fan did you use to get your fan to turn on and what was the wire flow to use a togle switch?

Thankks
Magus

[Bigjohnjr]

I went to Autozone and got some red wire (10 gauge) and a 30 amp fuse.

I ran the 2 runs of wire through the fire wall (down near the bottom you will see a gromet with a thick black cable for the hood release)

One wire from the positive post on the battery to the switch to a toggle switch back to the fan.

I tapped into the green wire (I don't remember if it was the light green or dark green) but it is the high speed on the fan.

The toggle switch I used is rated for 30 amps same as the fuse I used.

I did not measure the current for the fan, I would guess it would be around 20 amps since the wire chrysler uses is a heavy gauge.

[gordonwhitney]

Did anyone check the radiator fan fuse (link?). My daughter had a major overheating episode, and the mechanic said he had to replace the fuse -- don't know if this was a cause (probably) or result of the overheating.

[Vickers]

Originally Posted by Bigjohnjr

changed both relays

Hey Bigjohnjr, I am having the same problem (started another thread without seeing this one).

My big question to you: where ARE the relays for the fan circuit located? I have a 98 Caravan, and I tried to trace the cables back from the fan modules, but do not see a relay in-line. The relays in the fuse/relay box do do not seem to indicate one is for the radiator fans:

CIG & ACCY
FRONT WIPER HI/LO
FRONT WIPER ON
HI BEAM
LOW BEAM
HORN
A/C CLUTCH
BLOWER MOTOR
STARTER
PARK LAMP
EATX SHUTDOWN
FUEL PUMP
AUTO SHUTDOWN

Is one of those ALSO for the radiator fans? At first I though the "BLOWER MOTOR" might be that, but it is for the AC fan, right?

Thanks for your help!

Vickers

[Bigjohnjr]

There are 2 relays.

1 for high speed and 1 for low speed

They are mounted on the inner fender drivers side.

I think that are 4 or 5 relays in a row.

The 2 fan relays are NOT side by side.

I do not know what the other relays do.

The reason that there are relays is because the fan draws about 20 amps.

The blower motor is the fan for your heat/defrost/ac.

There are 4 wires on the fan, like I posted before. The 2 green wires are the +12 volt.

Light green and dark green
Black is ground
Yellow is unknown, might be a feedback for the computer.

[Bigjohnjr]

OK ALL FIXED!!!!!!!!!!!!!!

I got my temp sensor today from Jegs.

Attached to the upper radiator next to the thermastat.

Ran the wires for it along the firewall into the van, under the dash I wired it to a relay, hooked up the relay to the fan.

Ran the van, it got hot, fan came on, temp went down, fan turned off.

Simple.

[akmadmike]

All, Great thread.

I have the same problem mentioned above.
Fan not coming on. Tested fan straight to battery ok.
Manual states that good fan should run when temp sensor is unplugged
if bad sensor. Does this sound right? Did not work for me.
Am looking at the relays next? There are 4 on driver side fender panel.
Anyone know which are for fan? Have seen posting on high and low speed reply? Would fan work on just one good relay?

I also noticed that when overheating occurs the overfill bottle fills up.
Is this an issue? I did not know if the temp sensor is behind the
thermostat and the thermostat does not open whould this cause
the sensor to seem bad not allowing fan to run?
What other things would indicate a bad thermostat?

Thanks for any help,

[Bigjohnjr]

If you short the sensor wire to ground the fan should come on, or if you turn on the A/C.

If the fan does not turn on you have the same problem that we all have.

When the bottle overflows is because the coolent is too hot, it is boiling and then turns to steam and the presssure builds and wants to leave the system.

By cooling the coolent it does not boil over.

I do not at this time remeber what relay turns on the fan for the low speed but it has a green wire and a gray wire on it.

Just like the high speed it has a green and gray.

I do not remember if it is light green or dark.

Your problem most likley is not a bad thermastat.
The fan would still come on, bad thermastat and all.

Update on my end, I added another relay to turn the fan on when the a/c is on. I did not have to, I just wanted it to turn on whenever the a/c is on. Just like it use to.

If you need anymore help let me know.

John

[akmadmike]

John, The grounding of the sensor wire did not get the fan going.
I guess the sensor could still be good? I am a bit confused by the
high speed low speed thing. I know I have 2 fans. The one on the passengers side is for the A/C. It comes on when the A/C inside is on and the blower on high. The Fan on the radiator is the problem.

My Hayes book shows the 4 relays. If I am reading it right the the third one in from the front of van as the Radiator fan relay.
Does this sound right?

I am courious about your fix. How exactly did you mount the Jeg's
sensor? I could not find a universal temp sensor on Jegs web site. Does it replace the original? Did you run the wiring from the fan
motor to the sensor then to the relay? Did you use the same type of
relay as the original? How does the fuse fit in?
I hope this is not too many questions but I just hate to have to take
it to the shop and start getting the run around or over charged for
something I could take care of. I have done a bit of work on this
93 3.3 AWD Grand Voyager. Replaced starter, water pump, o2 sensor,
radio replacement. I am not very knowledgable on electrical things though.

Have you ever done the 'code' thing? I get a 34 I think this has been on there for a while and unrelated. When I had the temp sensor unplugged I got a 22. Coolant sensor voltage too high or too low.
Never got a 35 Radiator fan relay circuit problem.

It is really great to read other peoples experiences. You all have helped
just sharing the info!! I really like my van and hope to keep it until I can afford a Hemi Ram Pickup. I just dread the day that I can no longer keep up with the technology for minor problems.

Thanks again.
Mike