Fan Switch
Thread Starter
Racer
Joined: Nov 2007
Posts: 300
Likes: 1
From: Prescott Michigan
Fan Switch
Please, where is the fan switch on a 1987 L98? The FSM says it is next to the dip stick but the only thing there are 2 black looking sensors that are connected to the high pressure cooling line and a sensor to ground on the block. The switch that I am looking for is the one to change so that the cooling fan will come on at 190 instead of 227. I want to put a 180 thermostat in.....jim
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
If you have a aux cooling fan located in front of the radiator, the switch is located on the left side cylinder head between #1 and #3 spark plugs. Which fan are you wanting to come on early?
The ECM grounds the main fan to come on at the preset temp in the ECM chip. If you want it to come on early, you will need to have the chip tuned for this or wire in a toggle switch in the interior.
I suggest to make the fan come on at 200* if going with a 180* t-stat.
The ECM grounds the main fan to come on at the preset temp in the ECM chip. If you want it to come on early, you will need to have the chip tuned for this or wire in a toggle switch in the interior.
I suggest to make the fan come on at 200* if going with a 180* t-stat.
Thread Starter
Racer
Joined: Nov 2007
Posts: 300
Likes: 1
From: Prescott Michigan
If you have a aux cooling fan located in front of the radiator, the switch is located on the left side cylinder head between #1 and #3 spark plugs. Which fan are you wanting to come on early?
The ECM grounds the main fan to come on at the preset temp in the ECM chip. If you want it to come on early, you will need to have the chip tuned for this or wire in a toggle switch in the interior.
I suggest to make the fan come on at 200* if going with a 180* t-stat.
The ECM grounds the main fan to come on at the preset temp in the ECM chip. If you want it to come on early, you will need to have the chip tuned for this or wire in a toggle switch in the interior.
I suggest to make the fan come on at 200* if going with a 180* t-stat.
Burning Brakes
Joined: Jul 2003
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From: Plantation Fl
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Wiring in a toggle switch is easier, but not automatic like the chip. You will have to toggle it on and off when you want.
Thread Starter
Racer
Joined: Nov 2007
Posts: 300
Likes: 1
From: Prescott Michigan
See if this helps you out. http://content.madirect.com/pdf/609106.pdf
Thread Starter
Racer
Joined: Nov 2007
Posts: 300
Likes: 1
From: Prescott Michigan
You can purchase a aftermarket chip (hypertech or such), which is just will turn the fan on sooner, makes changes in A/F tables, timing, speed limiter, ect. These are fine for a stock car. You can pay a little more and have a custom chip/adapter tuned for more of your set up. You can usually pick and chose from a list of options you want done (fan on/off temps, VATS eliminate, EGR eliminate, timing changes, A/F changes, injector constant changes, speed limiter, plus more). A custom tune cost around $200.
Wiring in a toggle switch is easier, but not automatic like the chip. You will have to toggle it on and off when you want.
Wiring in a toggle switch is easier, but not automatic like the chip. You will have to toggle it on and off when you want.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
This CTS sensor doesn't do anything for turning the fan on. The ECM controls the main fan. You can change the aux fan switch to a lower temp switch. You need to make sure your car is optioned for the aux fan as some are not. The aux fan swith will ground the wiring to the aux fan at around 235*. This fan is pretty much usless if you have a tuned chip or toggle switch.
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From: Downtown Annapolis, MD. The Future is where we all have to live. Let's not screw it up.
St. Jude Donor '08-'09-'10-'11
http://www.mamotorworks.com/corvette-3-138-944.html
http://www.mamotorworks.com/corvette-3-138-943.html
Me, I just let the thing operate as it was designed to operate.
http://www.mamotorworks.com/corvette-3-138-943.html
Me, I just let the thing operate as it was designed to operate.
Thread Starter
Racer
Joined: Nov 2007
Posts: 300
Likes: 1
From: Prescott Michigan
http://www.mamotorworks.com/corvette-3-138-944.html
http://www.mamotorworks.com/corvette-3-138-943.html
Me, I just let the thing operate as it was designed to operate.
http://www.mamotorworks.com/corvette-3-138-943.html
Me, I just let the thing operate as it was designed to operate.
Burning Brakes
Joined: Oct 2003
Posts: 1,106
Likes: 1
From: Foresters Falls(near Ottawa) Ont
I installed a lower temperature sensor to turn on the AUX fan at a lower temperature but took it out and put the original back in.
The noise that the AUX fan makes was unbelievable!! Was downright embarrassing and it would come on at what I consider normal temperature. Seemed it was on all the time, especially at low speed.
I have considered a toggle switch to turn the AUX fan on though, 225F is a little high IMHO, although that's normal in most cars.
RonJ
The noise that the AUX fan makes was unbelievable!! Was downright embarrassing and it would come on at what I consider normal temperature. Seemed it was on all the time, especially at low speed.
I have considered a toggle switch to turn the AUX fan on though, 225F is a little high IMHO, although that's normal in most cars.
RonJ
Le Mans Master
Joined: Jun 2006
Posts: 5,642
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From: One day you're a Comet...the next day you're dust... Arkansas
Please, where is the fan switch on a 1987 L98? The FSM says it is next to the dip stick but the only thing there are 2 black looking sensors that are connected to the high pressure cooling line and a sensor to ground on the block. The switch that I am looking for is the one to change so that the cooling fan will come on at 190 instead of 227. I want to put a 180 thermostat in.....jim
I put a 205* switch on my aux fan and it runs more often than I would like in the summer.
Try that and leave your thermostat alone. If you try what you are suggesting, your fan on and stat open are too close together. Remember most stats START to open at their rating.
