HI folk,s this is my first post here, seems like some one can get lots of help here, which is why I'm here I guess. Ok I have 2 dodge vehicles to repair, a 01 caravan and a 02 durango, But right now working on the caravan, I got a p149 code so I replaced the relay and still no fans at high temps, Should the fan's run if I turn on the ac? Jumped the fans and they worked, tested the fuse with a test light its ok. now I'm looking for the temperature sensor. 3.3 liter, I think its behind the and under the ignition coil. so if any one knows for sure I'd appreciate the help, 3.3l 2001 caravan. I guess if that's ok all that's left is the pcm? How do you test that?
The durango is another story. Have the 4.7 oil sludge problem, looking like I need to rebuild the engine, Knocking like mad. checked to find another motor but it,ll be around 2 grand for a half decent used one so might as well rebuild. dont want to dump it, it is a nice truck to drive. any first things first. Thanks for any future help. Graham

 

HI again, was wondering if is this the right place to have this thread. over a 100 views but no reply's, any way I checked the heat sensor and it seems good, I forgot to mention, when I did the scan with my obd2 scanner a number of the icons would continually blink and would not finish reading. I tried to erase the code but it would not erase. would that be an indication that the pcm is malfunctioning? dont know what else to do but check a few wires to see if any are broken. Hope to get a reply. thanks Graham

 

Not sure of your problem. I just chased down an unusual over heating problem on my van. Changed out the thermostat, temp sensor, and radiator hoses and these did not help and verified that the fan was running. I did not suspect the water pump as it had been changed recently and it is pain to change it out, but it was next. It turned out the impeller was slipping on the shaft.

 

The sensor is located where you indicated. What was the exact code because there should be a 4 digit code?

 

When my 2000 GC w/ 3.3 overheated it was the radiator fans. the temp switch is below the driver side headlight, you have to look for it, hard to find.

 

Hi guy's, thanks for replying and the help. so far I checked every thing other than the pcm. Papaduk, I dont think it would be the thermostat or water pump. Than fans do work when hooked up direct to a 12 volt source.
Mfahey, I found the sensor and checked it in hot water and it seems to work.
the code is p1491 rad fan control relay circuit.
Chazwel, are you talking about the relay?
Does any one know how to check a pcm, have a feeling that's the problem but do not want to buy one and find out the old one is good.You would think a obd2 scanner could tell, I have the innova 3130, if anyone has experience with this tool would be cool if you can share your knowledge lol. Thanks folks.Graham

 

Here are some of the things that I found in my service manual:
GROUND CIRCUIT
FUSED B+ OUTPUT CIRCUIT
POWERTRAIN CONTROL MODULE
RADIATOR FAN RELAY CONTROL CIRCUIT SHORT TO GROUND
RADIATOR FAN RELAY CONTROL CIRCUIT OPEN (IPM)
RADIATOR FAN RELAY CONTROL CIRCUIT OPEN (PCM)
RADIATOR FAN RELAY CONTROL CIRCUIT SHORTED TO GROUND (IPM) RADIATOR FAN RELAY CONTROL CIRCUIT SHORT TO GROUND (PCM) INTELLIGENT POWER MODULE (OPEN) INTELLIGENT POWER MODULE (SHORTED)

Can you tell if you have 12v going to the relay when it be on?
If you do, then I would think you could rule out the PCM and any power distribution issues like a blown fuse and you should look at the ground for this circuit.

 

Thanks Mfahey for the help, turns out the wire between the fuse box and the fan relay broken some where. just placed a new wire between them and fans work good. Only problem I cant get a reading for my emissions and get a yellow light. took it for air care few days ago and it failed, probably because of the check engine light. I guess some of the monitors have not completed diagnostic and dont seem they are going to finish,so why would they not finish?Thanks for helping folks. Graham

 

I wouldn't think the 1491 code would be cause to fail the emissions test. Is there another one that is causing the check engine light to come on. You could disconnect the battery and see if the light comes back on but be warned that most emissions testing checks stored codes.

 

apparently it does fail with a check engine light on no matter the reason, they use a obd reader for the test .The light is off now so might pass aircare, but I have a yellow emissions light and the flashing icons. have no idea why it doesn't finish reading . Graham