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Cadillac Repair/1988 cadillac seville cooling fan fault


QUESTION: The two fan just stop working..i check the relay and the fuse they are ok....and try to look for the fan control module but no luck,is nothing on front or back the radiator..please help me i am a desperate ohh.just in case i got some codes..
b440,b441,b446,b447, current codes.and some several history..e028,e048,e052,e059,e067,b112,b120,b121,b122..thanks..

ANSWER: Hello,

There are many reasons that the cooling fans may not be oprating, amd one might be a bad Ecm (Computer) esprcially with yhat many codes. The more important question is what made you notice that thr fans were n working. If you overheated this aluminum engine, you have much more severe concerns. If this engine over heats or goes above 220 for safety sake, catastrphic failure to the engine is already happening. If the coolant is not circulating the temp srnsor will not turn onfans.
Diagnostic codes in these older vehicles are worthless because they are so general. They also have a cascading effect in which one code can set off another snd another all for the same symptom.
Your problem requires physical examination of the vehicle and unfortunately cannot be fixed over the internet without you replacing perfectly good parts and still not repairing the problem. I wish tgat I could supply you with a silver bullet for an answer, but I am afraid you will have to take the car to a service garage ((not a dealer).

Good luck.


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QUESTION: My husband  notice a warning light on, for few minutes in a stop traffic,but when he continue on open road, the light go away.
But I notice that before when I turn the key in on,both fan turn on and now that's no happening . So i asume they are connected direct.? Can be some cables problems? ......... I went on this car from Maine to Florida and then to Texas and back to Maine in a single trip with no problem.   Last month We put a new radiator... And I can tell you that this car is really good in gas and run like a I just I Love it.)..... Thanks a lot for your time.


Fans are meant for city driving because on the highway there is enough air flowing through the radiator. If you turned the key on and heard the fsns the a/c or defrost was enabled at the time. The engine does not have to be running in this situation.
The aluminum engine becausr it is light weight gives good economy and performance, but unlike a cast iron engine, these engines begin to melt if the hot light is on.
Over the last 1o years on this site I habe answered hundreds of questions related to catastrophic failure of these engines when over heated. You will not find a good used engine for your car if you needed one because they hsave all been overhested.

Please excuse any spelling errors. My computer crashed and I have been supplying answers through my phone. Everything is like in an 8 font and I cant see what I am writing.


---------- FOLLOW-UP ----------

1988 cadillac seville
1988 cadillac seville  

1988 cadillac seville
1988 cadillac seville  
QUESTION: I see.. But no, as soon I turn the key on both fans  start working and no AC or heather on... And like I tell you before I can't find the Fan Control Module.. Instant I see a couple of cable with black tape on the top of front fan....??. Here is a 2 pics....


Good pics. Looks like factory tape and orange labels. My concern though is the fans are not supposed to run except as I described to my knowledge. I no longer have books for that vehicle. Possibly your local library might have a factory service manual for the vehicle. That will tell you everything you need to know, or you could check Craigs or Ebay to purchase one. The factory service manual can save so much money because diagnostics to all electrical/electronic systems are in it, plus anything you need to know about the vehicle.
I do not any longer remember any module locations on your type of vehicle, because of servicing so many years, makes and models since then.
My main reason for concern is that constant running does effect the fan motor's life.
The only time they were designed to run was in city driving where air was not rushed into the radiator at highway speeds, when the fan blowers are inert. The exception would be having the A/C or defrost on with the ignition on.
If my spelling is better, I am on a computer now and can ctually see what I am writing lol.

Good luck!

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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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