Radiator Fan

Quiksilver · **Posted:** Mon Apr 12, 2010 5:26 am

Hello All

I have a 2006 Liberty CRD. The other day i noticed that the engine was getting very hot (over 3/4 on temp gauge) i pulled over and looked under the hood to double check that raditor etc was all looking ok just as a precaution. It was a very hot day in thick traffic. What i did notice was that the fan in front of the radiator was not on, surely this should be on at these temperatures?

what could the problem be? is there a relay or fuse i need to check.

Only a problem in very hot conditions with low speed driving, otherwise temps are perfect so don't think any problem with actual radiator/cooling system.

thanks in advance for replys

Billwill · **Posted:** Mon Apr 12, 2010 7:42 am

My circuit diagram for the 2002 CRD shows the fan being driven by Fuse 2 (40A) in the PDC which goes first to the Radiator Fan Relay which I believe is mounted somewhere in the engine bay. Get one of the guys here with the newer CRDs to hopefully post you a picture of where this relay is located.
Strangely, the circuit diagram seems to indicate that the fan can rotate in either direction :?:

This seems very weird, maybe a typo!
I am sure the CRD experts here will be able to give you some more advice regarding your cooling problem.

CATCRD · **Posted:** Mon Apr 12, 2010 6:22 pm

It sounds like a problem with your viscous fan clutch not engaging to drive the main fan fast enough. Was it really roaring when you popped the hood to look?

Years ago there was a TSB from the dealer where they would reflash your computer to recalibrate the temp gage to prevent false overheating warnings.

Quiksilver · **Posted:** Tue Apr 13, 2010 6:06 am

CATCRD wrote:

It sounds like a problem with your viscous fan clutch not engaging to drive the main fan fast enough. Was it really roaring when you popped the hood to look?

Years ago there was a TSB from the dealer where they would reflash your computer to recalibrate the temp gage to prevent false overheating warnings.

Sorry don't know what you mean by really roaring? engine was at idle and the fan on the radiator right in the front of the engine was not turning.

CRDMiller · **Posted:** Tue Apr 13, 2010 6:56 pm

Based on my observations, the electronic fan does not engage unless the air conditioner is, or was, on.

ATXKJ · **Posted:** Tue Apr 13, 2010 7:06 pm

The mechanical fan clutches tend to die

Kap posted the test procedure here

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?p=575149#p575149

kapalczynski · **Posted:** Tue Apr 13, 2010 9:04 pm

Quiksilver wrote:

Hello All

I have a 2006 Liberty CRD. The other day i noticed that the engine was getting very hot (over 3/4 on temp gauge) i pulled over and looked under the hood to double check that raditor etc was all looking ok just as a precaution. It was a very hot day in thick traffic. What i did notice was that the fan in front of the radiator was not on, surely this should be on at these temperatures?

what could the problem be? is there a relay or fuse i need to check.

Only a problem in very hot conditions with low speed driving, otherwise temps are perfect so don't think any problem with actual radiator/cooling system.

thanks in advance for replys

Low speed driving is primarily where the fans are necessary. The main fan is connected with the viscous fan clutch and almost freespins unless the clutch engages. When the fanclutch engages you should hear a much louder fan noise that is even noticeable inside the cabin itself above 2000 or so RPM's. The electric fan is a 2 stage fan that comes on much later at higher temps. I'm not sure exactly what temp your gauge was showing numerically, but I had the same issue where I was at about 3/4 on the gauge with the mechanical fan/fan clutch not engaging properly. I have since tested the fan clutch (I posted procedures on different thread, see quote below).

In an emergency when overheating like you were, you can run the AC and turn the temp dial to HOT with the fan on high. this will do 2 things to help bring your temp down. 1) engage the auxillary fan on the radiator cooling the engine. 2) run coolant through the heater core (heat the cabin) thus remove heat from the engine as well. If this doesn't bring you down to temp then you will have to pull over and let the engine cool.

After verifying it was bad, I replaced the fan clutch with a new flex fan and adapter that replaces the fan clutch entirely. See my other thread here: http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=51618

The new adapter (replaces fan clutch) and Flex fan (replaces factory fan) is a solution to the failing clutch problem that will never fail again. It is half the weight, about $50 cheaper than a fan clutch alone, provides far superior, and so far in my testing has not shown any adverse fuel economy results whatsoever.

Please feel free to browse the forum link below and follow the simple test procedure to see if your fan clutch has failed. Shoot me a PM if you would like more info on my fan clutch/adapter/spacer setup.

ATXKJ wrote:

The mechanical fan clutches tend to die

Kap posted the test procedure here

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?p=575149#p575149

I also have designed a way to machine the thermostat housing, and made a replaceable thermostat that can run at 192* (recommended temp from GDE) instead of 176* to improve the economy a bit.

Quiksilver · **Posted:** Wed Apr 14, 2010 7:37 am

Hi Guys

thanks for the responses - after some further investigation i can clarify my original question some more.

When i first checked I assumed the electrical fan in front of the radiator was the only fan.

On closer inspection is see there are two fans, a mechanical one between the engine and radiator and another attached directly to the radiator that you can see through the grill - i handn't noticed the main an because of the engine shroud. woops

Anyway is see the main fan is working fine (so my clutch is obviously ok too)

This leaves me with a updated question then, why isn't the secondary electrical fan coming on when the engine is getting very hot and why might that happen. I tried with A/C on doesn't seem to make a difference, i can hear A/C turning on and off etc, no fan. A/C works as normal in cabin.

Is the engine getting hot like this just something that happens on the CRD. As originally mentioned it only happens very occasionally when its very hot plus low speed driving.

Thanks

LibertyCRD · **Posted:** Wed Apr 14, 2010 9:11 am

GDE says that the e-fan should kick on around 203 degrees, which is just past the half-way mark on the temp. guage. I don't notice this happening with mine. I wonder what the real temp. is for that fan to kick on?

Quiksilver · **Posted:** Wed Apr 14, 2010 9:16 am

I see there are some relays and fuses for the e-fan, all mine look fine although i don't know what a dead relay would look like.

kapalczynski · **Posted:** Wed Apr 14, 2010 10:19 pm

Quiksilver wrote:

Hi Guys

thanks for the responses - after some further investigation i can clarify my original question some more.

When i first checked I assumed the electrical fan in front of the radiator was the only fan.

On closer inspection is see there are two fans, a mechanical one between the engine and radiator and another attached directly to the radiator that you can see through the grill - i handn't noticed the main an because of the engine shroud. woops

Anyway is see the main fan is working fine (so my clutch is obviously ok too)

This leaves me with a updated question then, why isn't the secondary electrical fan coming on when the engine is getting very hot and why might that happen. I tried with A/C on doesn't seem to make a difference, i can hear A/C turning on and off etc, no fan. A/C works as normal in cabin.

Is the engine getting hot like this just something that happens on the CRD. As originally mentioned it only happens very occasionally when its very hot plus low speed driving.

Thanks

First off, how are you verifying the correct engagement of the main fan? You said it is working....but what makes you say that? It always spins, it just spins faster when the clutch engages and you will hear MUCH more fan noise and air flow is greatly increased. The electric fan could be disconnected at the connector if the vehicle ever had the intercooler out it is necessary to disconnect and it may not have been reconnected. Before checking for that, first check the underhood fuse compartment. Look for the fuse or relay to that fan and ensure it is ok. Then if all seems well there, look for the harness right behind where the rubber air shield on the passenger side of the intercooler redirects air into the intercooler. There is a small bulge in the rubber redirection piece. Behind that is the connector to the electric fan. If it is connected then you can disconnect it and test it with 12 volts to check if it works at all. If it does work, then the problem is before that part of the circuit and needs to be traced back further. There should be voltage at the fuse/relay box underhood when the AC is on. I forget what temp it kicks on and if it is a fuse or relay or both. I do not have my manual with me here as I am away on business. Hopefully this gives you a starting area to check the electric fan.

Hope this helps, I have all the specs and test procedures at home. You should try the test procedure to test the fan clutch first as that will eliminate that problem and also you will hear the difference the noise of the fan engaging if it works so you can see the difference.

Pleas reply back or shoot me a PM if you have more questions. Shoot me your cell number or I can give you mine in the PM if you need more help. Always glad to help.

- Mark

kapalczynski · **Posted:** Wed Apr 14, 2010 10:20 pm

Quiksilver wrote:

I see there are some relays and fuses for the e-fan, all mine look fine although i don't know what a dead relay would look like.

The relays with the same part numbers are interchangeable and they can be switched to eliminate a faulty relay by switching a non-critical relay with the suspected faulty one.

Try this for the relays.

- Mark

LibertyFever · **Posted:** Sat Apr 24, 2010 11:12 pm

I have a gasser Liberty, or as you CRD guys call it a "spark infested" Liberty and I have some knowledge as to the operation of the cooling fans.

From your posting it sounds like you have both a mechanical or viscous fan and an electric fan.

Just because your mechanical fan is spinning when the engine is running doesn't mean it's actually fully working. Once your engine is warmed up shut off your engine and try spinning the fan. If it has resistance then it's working. If it spins freely then you likely need a new one.

The electric fan operation is more complicated. On a gasser Liberty the PCM controls the electric fan, I suspect it operates the same on a CRD. The PCM decides when and how fast the electric fan runs depending on the coolant & battery tray temperature, vehicle speed and whether or not the A/C is on. If I understand the FSM correctly if you turn on the A/C while the engine is warmed up the electric fan should come on.

Your engine is apparently overheating just in traffic not while towing so I suspect other issues with your Liberty other than your electric fan. If the mechanical fan isn't bad then I'm going to suggest you start replacing the cheapest items first starting with the thermostat.

Radiator Fan

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