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Cooling Fans


Mantis421

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93 STS (Northstar) After replaceing the engine, I have yet to get the fans rolling correctly. If I unhook the battery and then rehook it, they come on during the first start, but never again. Obviously they do function, just not when they are supposed to. I do NOT have the AC charged as of this point and all those codes are set of course. I have no fan codes though.

Relays are replaced...

Does not having the AC charged (working) cause the fans not to function?

Thanks All

PS <_<

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Where did you get the engine? Is is possible that the temperature sensor is defective or that you left the connection off the temp sensor? I would test the sensor. Mike

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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the fans turn on when the coolant temp. reaches 225-230 degrees. are you sure you get that point?

Yeah, if the fans never turn on, that's not necessarily a problem, unless your engine is overheating. They'll never get commanded to turn on because the A/C compressor is engaged (since it's not charged), but the computer should still command the fans, at low speed, around the 229*F threashold. Does your DIC display the actual coolant temperature, or do you just have the gauge, which acts more like an idiot light? On mine, the gauge will stay straight up until the temperature rises to 220*F or more. Then it starts to move toward the next line, but the fans will kick on and lower the temperature, and the gauge returns to straight up.

Is your gauge reading in the red?

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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From what I have learned, the cooling fans have 3 settings. LO MED HI. And it uses them at different temps.

Temp Sensor was replaced new when I put in the engine. I have had the temp up to 230, still no fans... I will test my sensor again though... any other help?

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Jadcock, I have the DIC only. No gauge. I was under the impression that the fans would come on at an erlier temp, at least low speed?? Maybe I should do some more reading. It just seems that they used to run before, but you know how that it :)

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If it's getting to 230, they should have come on by then. There are only two speeds, LOW and HIGH. Low is commanded around 229*F. High is commanded around 235-240*F. It uses the three relays to select between the two speeds. I don't know how many temperature sensors the PCM uses -- I thought only one. If your DIC reads 230, then your computer knows how hot the engine is and should be commanding the fans on.

I wonder if some of the wiring is backwards or the relays were installed "backwards", if that's even a possibility?

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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If you have an ohm meter the temp sensor should excite (cause a rise) your meter as the temp rises, if I cam not mistaken, the computer ultimately turns the fan on by reading the sensors data. I am not sure if the manual gives proper resistence ranges for the sensor, have you tried the old one since the fans worked? Mike

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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Scotty and Jadcock. Thanks so much for your quick replies. Manual is little help. Maybe I should try the old sensor. I did not desturb the wiring on the relays. I'll keep looking.

Thanks Much

PS

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on my 93 sts the cooling fans come on at 225 -226 on low speed then cut off around 217-212. the high speed fans come on at 232-235. if the a/c is on auto, the fans are on contnuously. how high is you temp getting before you check the fans? if it is getting to 230 and no higher, may be they are coming on.

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on my 93 sts the cooling fans come on at 225 -226 on low speed then cut off around 217-212. the high speed fans come on at 232-235. if the a/c is on auto, the fans are on contnuously. how high is you temp getting before you check the fans? if it is getting to 230 and no higher, may be they are coming on.

I will run up the temp to 230 and check again, we'll see

thanks

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Have you tried to command the fans on through the dic? you can enter the diagnostics and do this.

Enter diagnostics by simultaneously pressing and holding

the 'off' and 'warmer' buttons for several seconds. You'll see

the display check and then any codes displayed. After the codes

(if any) then the DIC will show a message "PCM?" At this point

remember that the 'lo' button is no and the 'hi' is yes. Answer

yes to the PCM? prompt by pressing the 'hi' button. The display

will then show 'PCM DATA?' answer no by pressing lo. Then it

will prompt 'PCM INPUTS?' answer no. Then it will prompt 'PCM

OUTPUTS?' answer no. Then it will prompt 'PCM OVERRIDES?'

answer yes with the hi button. Now scroll thru the PCM override

functions with the lo or hi button until you find PS08 which is

the cooling fan relay. Pressing the 'cooler' button will turn

the fans on low speed with the low speed fan relay. Pressing

the 'warmer' button will turn the fans on high speed with the

high speed fan relay. To exit press 'off' repeatedly or just

turn the key off.

Hope this helps.

john

John

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IT WORKS... I'll me D$#%#@ 223 both fans started after checking relays!!!!

So what was wrong? Was one of the relays not fully plugged in or something?

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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NICE! What was wrong? Mike

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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I had a previous relay from the original engine from my 93, replaced it, fun to get to. I was under the impression that relays don't "GO" that often. But I guess it did. From what I gathered, 220-230 F is the typical start-up on the fans, I thought it would be sooner, but guess not.

Thanks Again you 2

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