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Cooling Fans


Scotty

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Living on Long Island, where being is bumper to bumper traffic is a normal event, I was wondering if can change the cooling fans to turn on sooner. Would that make any difference in bumper to bumper traffic anyway?

The second thing I want to ask is can I put a slightly lower temp thermostat in, its 195, can I put a 190 to start the meltdown at a lower temp overall? I DO NOT like seeing temps in the 224 to 230 range without the AC on in traffic. My AC compressor is broker and out of the circuit and I still get the 224 to 230 temps. I can ONLY image what I would have had with the AC on..... Any ideas? Mike

Bbobynski, I know you are going to say these temps are not a big deal, but I would like to do better, will a 190 help do you think?

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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Mike,

Didn't you recently bypass the A/C compressor with a shorter belt? If so then wouldn't putting the A/C on effectively turn on the fans? Or does the compressor have to be pluged in? If so just take a 2" piece of 12 or 14 guage wire, strip back the isulation and pound the copper tip to a spade on each end. Then bend it into a "U" shape and jumper the plug making the PCM think the A/C circuit is complete and turning on the fans. Tape it all up to prevent any shorts. ;)

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These last few weeks we have temps in the 90s here in Baltimore, and my coolant temp has been in the 217 to 234 range with the A/C on. I think the fans come on at hi speed at 234. The funny thing is at night when I leave work, the temps are around 78 - 80 degrees and my coolant temp stays at 196, even with WOTs to 125+, but I wouldn't tamper with the stat, keep the OEM specs.

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Don't the fans run continuously when the AC is on? With my AC running, in 90F weather, my engine coolant temp rises to about 217 give or take a few degrees in bumper-to-bumper conditions otherwise, it's about 203. With the AC off, the temp can rise to about 223 in 90F weather at which point the fans turn on and the temp comes back down to 203 very quickly.

If you really want to make people safe drivers again then simply remove all the safety features from cars. No more seat belts, ABS brakes, traction control, air bags or stability control. No more anything. You'll see how quickly people will slow down and once again learn to drive like "normal" humans.

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My AC compressor is broker and out of the circuit and I still get the 224 to 230 temps. I can ONLY image what I would have had with the AC on.

Your temperature would be lower and much more stable if you had the A/C in the circuit. Without the A/C on, the fans are only commanded on when the temperature reaches 229*F -- that's low speed. High speed is commanded a few degrees higher, like 236*F or so.

If your A/C was operational, or if the PCM thought it was, the fans would cycle on/off as long as A/C is commanded on via the HVAC panel. I've found that mine don't run continuous while A/C is on, but they cycle on for a minute, then off for 30 seconds, then back on, etc. Still, it's enough to keep temperatures in the 190-215*F range, even in traffic. If I'm in stop-and-go for at least 10-20 minutes, the temperatures will start to creep towards 229*F, but that's because the heat is exceeding the fans' cycling on/off with the A/C. Once the temperature reaches 229*F, the fans stay on steady, and turn back off when the temperature drops to 210-212*F. This is all normal and, although higher than we might be used to with "conventional" engines with mechanical fans, it's no harm.

I suppose you could hard-wire your fans on with the ignition on. But that'd be a grand waste of electricity. I'd leave it as is. I don't think there's a way to re-program the fans' "ON" threashold. Maybe with a Tech II?

Jason(2001 STS, White Diamond)

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

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My AC compressor is broker and out of the circuit and I still get the 224 to 230 temps.  I can ONLY image what I would have had with the AC on.

Your temperature would be lower and much more stable if you had the A/C in the circuit. Without the A/C on, the fans are only commanded on when the temperature reaches 229*F -- that's low speed. High speed is commanded a few degrees higher, like 236*F or so.

If your A/C was operational, or if the PCM thought it was, the fans would cycle on/off as long as A/C is commanded on via the HVAC panel. I've found that mine don't run continuous while A/C is on, but they cycle on for a minute, then off for 30 seconds, then back on, etc. Still, it's enough to keep temperatures in the 190-215*F range, even in traffic. If I'm in stop-and-go for at least 10-20 minutes, the temperatures will start to creep towards 229*F, but that's because the heat is exceeding the fans' cycling on/off with the A/C. Once the temperature reaches 229*F, the fans stay on steady, and turn back off when the temperature drops to 210-212*F. This is all normal and, although higher than we might be used to with "conventional" engines with mechanical fans, it's no harm.

I suppose you could hard-wire your fans on with the ignition on. But that'd be a grand waste of electricity. I'd leave it as is. I don't think there's a way to re-program the fans' "ON" threashold. Maybe with a Tech II?

Maybe that is why I was running hot yesterday. The AC compressor has been eliminated so I had the AC OFF. That would impact when the cooling fans turn on, and the car would appear to get hotter on average (maybe). Maybe I should see if I turn on the AC if the fans come on. I do have the compressor disconnected from power as the clutch is shorted from the heat of the hub burn out.

Once I get the Compressor back in I was hoping to cause this thing to run cooler by

1) having the cooling fans come on sooner, however with the AC they are on anyway, and

2) use a lower thermostat maybe 190 instead of 195, in the summer. Given that its summer, it will get to 195 anyway, but the temperature floor would be lower and maybe that would translate into a lower high end Temp!

Any ideas? I kn0w that is has been said that temps in the 225 to 235 range are fine, but they make me nervous regardless. Maybe I am the type of person that needs the old unresponsive analog temp guage. 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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Maybe I am the type of person that needs the old unresponsive analog temp guage. Mike

Or IDIOT LIGHT!!!! I wanted to say that before someone else did, I left myself WIDE OPEN for that one! :lol:

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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2) use a lower thermostat maybe 190 instead of 195, in the summer. Given that its summer, it will get to 195 anyway, but the temperature floor would be lower and maybe that would translate into a lower high end Temp!

This would not be the case. 195 is the temperature the thermostat starts to open. It's wide open by 212 or something like that I think (unsure of the actual wide open spec on the Northstar thermostat). But anyway, it's certainly wide open by the time you're above 220, meaning it's flowing all the coolant it can. The temperature is rising because of a lack of airflow across the radiator, and "hot" coolant getting circulated back through the engine. This is evidenced by the fact that you car never does overheat, even though the thermostat is wide open. Around 230*F, the cooling fans turn on (they aren't even on before that) and your temperature should then fall.

My OE thermostat held the temperature while cruising right around 200*F. 199-201, somewhere in there. When I did the water pump, I installed a new AC thermostat, and its opening temperature seems a lot lower. It's not because it's a different temperature thermostat; I just think it's on the lower end of the acceptable range. Anyway, my car cruises right at 190*F. In traffic, it'll climb to 194-196, and up above 200 if I'm sitting in traffic, in Drive, and not moving. So I, in effect, have a thermostat that is 10 degrees "cooler" than the OE one, just by chance, but the temperature ceiling is still the same, because it's controlled by airflow across the radiator. Remember, up above 210*F or so, the thermostat is wide open anyway.

Jason(2001 STS, White Diamond)

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

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By the way, I was looking through my '97 service manual and came across the specs for the OE thermostat. Opening temperature is 188*F. Wide open is 206*F.

Jason(2001 STS, White Diamond)

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

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By the way, I was looking through my '97 service manual and came across the specs for the OE thermostat. Opening temperature is 188*F. Wide open is 206*F.

Thanks Jason, 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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What i do it`s when i`m wot i turn on both fans on with the pcm override PS08, so they`re both on while the coolant temp it`s about 90*c and then when i stop the car it`s about 96-100*c that`s the way i do it.

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What i do it`s when i`m wot i turn on both fans on with the pcm override PS08, so they`re both on while the coolant temp it`s about 90*c and then when i stop the car it`s about 96-100*c that`s the way i do it.

Thats a good idea override the fans to high! Good Idea! Can I override the fans then exit the diagnostics and have the system work as "normal" with the fans overridden? 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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no... well i can`t when u get out of the system the pcm shuts both off but i always drive with the coolant temp on the dic so if you override them then u go to pcm data PS04 and taht`s the coolant temp in degrees celcius so u know that the fans are on and the coolant temp!

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no... well i can`t when u get out of the system the pcm shuts both off but i always drive with the coolant temp on the dic so if you override them then u go to pcm data PS04 and taht`s the coolant temp in degrees celcius so u know that the fans are on and the coolant temp!

THANKS FOR THE TIP! 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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Mike,

I have done exactly what you are looking at doing. Basically i have installed a rocker switch in my console when swiched on it basically supplies a ground to one of the relays and turns the fan on to the high position. Its the same wire coming from the PCM to the relay. I used the schematic in my factory manual to find the wire at the relay soldered a wire to this and brought it back to my console. then pulled a wire from a body ground to the switch.presto instant bypass when ever you like.I also ran an ignition source so my swicth lites up when ingaged.

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Mike,

I have done exactly what you are looking at doing. Basically i have installed a rocker switch in my console when swiched on it basically supplies a ground to one of the relays and turns the fan on to the high position. Its the same wire coming from the PCM to the relay. I used the schematic in my factory manual to find the wire at the relay soldered a wire to this and brought it back to my console. then pulled a wire from a body ground to the switch.presto instant bypass when ever you like.I also ran an ignition source so my swicth lites up when ingaged.

careldo, that sounds good also, I need to order a manual this week, Thanks 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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