[D725U]

My RFI module took a dump a few days back. Radiator fans run all the time. I don't need the extra cooling power this time of year (and yes, it's not the A/C transducer). I removed the high-speed fan relay as to not burn out the fan motor.

Of course Chrysler no longer carries this part. eBay is equally useless. Car-part.com lists some complete radiator assemblies w. condenser attached in Ontario but I don't want to have to buy extra parts just for one silly module.

Does anyone here have one lying around (or two, or three)? Apparently this part was used beyond the LH platform.

 

[peva]

never mind

 

[D725U]

It’s an electronic module that’s connected to the radiator fan assembly and controls the speed of the cooling fans. When it fails, it causes the radiator fans to run on high-speed mode as soon as the engine is turned on.

 

[peva]

It’s an electronic module that’s connected to the radiator fan assembly and controls the speed of the cooling fans. When it fails, it causes the radiator fans to run on high-speed mode as soon as the engine is turned on.

I hesitate to mention this because it may not apply to the 1st gen and it might just confuse things, but I believe the second gen PCM forces the fans on full time if either one of the two fan speed relay circuit's opens up (like if you were to remove one of the relays (goes back to normal operation after engine shut-down/re-start cycle if problem is corrected, i.e., relay re-installed) - but if the fans are cycling on and off with the one relay removed, then that must not be the case with 1st gen.

Maybe you're saying that the rfi module is what normally controls fan speed rather than the PCM doing so like on 2nd gen?

I take it that the module is sealed or potted and is not something that can be easily taken apart and troubleshot/repaired?

 

[D725U]

My understanding is that there's two modules that regulate the fans - the A/C transducer and the RFI module. If one or both fails, the system goes into a fail-safe mode and causes both fans to run at high speed continuously with the engine running to avoid overheating. Not sure if the PCM controls fan speed in the first gen. I hope not since I don't want to start hunting for computers for this car.

Years ago, my A/C transducer failed during the winter, and it caused the fans to run all the time. I had a new switch soldered in and everything was good with the fans up until a few days ago. I no longer have A/C connected to the car since the condenser developed a hole two years back so the transducer switch is disconnected. Doesn't affect anything but for some reason the RFI decided to go. My mechanic tested both modules and it was determined that the RFI is to blame and it's likely due to age (the car will be 29 years old in June).

As for removal, the RFI is not difficult to access and there's plenty of space under the hood now that I don't have a condenser and compressor hooked up. The b*tch is finding a replacement module and it seems to be unobtainium at the moment. There's a few threads on the DI forums about the RFI going bad and requiring replacement.

 

[EagleESI]

I may have one under the house. No clue on it's "goodness" but was working when pulled 6 years ago.

You are talking about the part mounted on the fan shroud yes?

 

[D725U]

Yes, it’s the module that sits on the fan shroud.

 

[EagleESI]

Yes, it’s the module that sits on the fan shroud.

I will root around tomorrow. I know I have atleast one fan shroud down there for sure.

 

[D725U]

Thanks for the help.

 

[EagleESI]

One I have. been ins storage for some time.

I did find this.

 

[D725U]

Looks like the connector is partially melted in the last pic. Did it overheat or make contact with something?

 

[EagleESI]

Looks like the connector is partially melted in the last pic. Did it overheat or make contact with something?

Was firmly connected to the motor. I would assume it's never been removed and this is from the large amp draw it sees when in high fan mode.

 

[D725U]

I’ll show the pics to my mechanic to get his opinion on the connector.

What are you looking to get for the RFI?

 

[peva]

Was firmly connected to the motor. I would assume it's never been removed and this is from the large amp draw it sees when in high fan mode.

Assuming the wire size and terminals were adequate for normal fan current on high speed, more likely is that the mating terminals developed high resistance due to female terminal loosing its spring pressure and/or corroding, or the design was marginally adequate and current went up due to failing (dragging) or locked up fan motor.

 

[EagleESI]

I’ll show the pics to my mechanic to get his opinion on the connector.

What are you looking to get for the RFI?

Just cover shipping really.

 

[D725U]

Talked to my mechanic this morning - he advised not to use that module based on the state of the connector. Soldering in my connector (which is still in good shape) is not recommended either (at least in his opinion).

I contacted National Moparts in Beaverton, ON and they unfortunately scrapped their remaining LH cars (they do have parts for a 51 DeSoto if anyone’s interested)😎 I was last up there in 2017 and got some wiper arms and a throttle cable for my 94. Their newest car in stock is a 91 LeBaron convertible.

This RFI module was also briefly used in the Cloud Cars so I’m going to hit some yards on Thursday to see if I can find one. I know there’s one sitting in Cookstown (96 Stratus).

 

[D725U]

Just an update regarding the RFI module:

Apparently the part number is the same for the Cloud Cars - I was able to find a working module from a 95 Cirrus with the 2.5 V6 engine at my local auto wreckers. Unfortunately the guys there wanted me to purchase the whole cooling fan assembly, so I ended up spending an unnecessary $100+tax for just a stupid module.

The positive thing is the module from the Cirrus fan assembly works and I've been driving for over two weeks without the blasted fans running continuously on my 94. Even though the RFI module is the same, the cooling fans are smaller on the Cirrus and won't fit a 3.5L application. Does anyone need a cooling fan assembly for a Cloud car? Hopefully I can recoup some of the money spent on this module.

The other thing is I noticed a gurgling noise from the coolant reservoir after the RFI module had been changed. My mechanic pressure tested the system and noted that the coolant was at the correct level (it's hard to see from the outside since my factory coolant reservoir is so yellowed from three decades of use) and there were no visible leaks found. The car idles fine and does not overheat - thankfully. He mentioned an air pocket may have formed because the engine was not heating up properly with all of the excessive cooling being drawn from the fans (the radiator was ice cold too which didn't help things in below freezing weather). The gurgling seems to have stopped after he pressure tested the system. Oil level is normal. The weather was mild yesterday so I got to really test out the RFI module in stop-and-go traffic.

 

[peva]

Glad you found the module. Good work tracking it down! 👍

 

[Firem]

Good to know the “cloud car” module worked out well.
Gurgling could have been air or pressure cap not sealing.
Gurgle after shutting off usually is a bad cap.

 

[LUNAT1C]

For all the griping people do about "parts binning", sometimes it works to our favor.

I'm sure you can toss the Cirrus fan assembly onto the Canadian equivalent of Craigslist (Kijiji, I think?) and find a buyer to get some cash back.