I know there are so many of you smart vette owners out there so someone should know how to install a manuel fan switch.

 

 

What model year helps.
Fan control varies across the years so "one size does not fit all"
You can install a aftermarket fan switch in parallel with the computer control to turn fan on at lower temp automatically. No manual switch needed

 

230 won't hurt anything. But for you nervous nellies you can parallel a spst toggle switch from ground to the grn/wh wire on the fan relay. The computer grounds this wire to turn on the fan relay. I have an 87, the fan relay wire color going to the computer might be a different color on your vette.
GM says to shut the engine off at 260 F and let it cool down. I doubt you will ever see 260.

 

Although 230 is hotter than most "old school" guys like to see, it will cause no harm.
In a modern cooling system with everything operating as it should, the boiling point is close to 260 F.

You can also turn on the A/C to force the cooling fans on if you want.
With the A/C running, my '96 will stay in the 205-210 range as long as I sit at idle. Once moving, it drops back down to the 195-198 range.

 

Don't mess with it.

 

230 is not that bad. Do the temps drop when the secondary fan starts or when you turn on the A/C?

It would be worth the effort to first clean out any dirt and debris that is lodged in between the tubes and fins of both the A/C condenser and radiator. All of the air for cooling comes from the underside of the car and build up of dirt and debris over time will reduce the ability of the radiator to cool properly.

Use a garden hose with a nozzle from the fan side to flush out any junk. You can also use a vacuum to suck out dried-up stuff before the waterboarding.

After doing the cleaning, see what the coolant temps are. If they drop to where you see 195-220 range, that will be fine. In city traffic, higher temps are typical due to less air flowing thru the radiator. So what you see is norma. The ECM will handle running the secondary fan as needed. LT1 motors run hotter as the increased coolant temps help with emissions.

 

I am one of the old-school guys. Put in both a manual switch and a low temp sensor. That was 5 years ago. Haven't used the switch yet. I understand the logic for a switch but doubt one is actually needed.

 

hai, i gottsa idea...

Before going through the trouble of modifying anything, how about making sure what you have is serviced properly.

Have you pulled the radiator and had it boiled out or replaced all together?

How is your Water Pump performing....everyone cliams that they are a light switch and either they work or the they don't........I do not believe that could be true. A wallered out fluid pump WILL NOT work as well as a new liquid pump.....

Have you thoroughly flushed your block?? Can I come check your overflow tank for Ruddy brown coolant?? Are you being honest with yourself by saying it is clean yet when you look in the tank it is Brown and not Green?? If so, you have to continue to flush until it is clear green after two days or running. It's like a Mop....if you mop the floor and rinse the mop after....and dirt comes out of that mop.....you need to go over that area of floor again....and again....and again until that Mop is clean when you rinse it. The coolant ports are just the same.....keep flushing until that thing is clear. And by flushing.....Fill it, run it a few days and then drain it....check the color of the fluid.....if it is clean then you are done. PIA?? absolutely.......It took me over 6 times (lost count) but guess what?? My heater started working........(hint hint)

Have you cleaned all the crap out between the condenser and radiator?? If this question confuses you, then you haven't performed this task....Once again a PIA of a chore that needs to be performed.

IF you do all these things.......IF......IF.......and after you still see 230° + temps on a hot summer day, come back and ask that question again.

 

I was looking at installing one on my '96. Because it's OBDII it gets very complicated at least for me anyway. I discovered something though. Since I only wanted this at the drag strip for a quick cool down I thought maybe if I unpluged the AC compressor the fans would still come on when I turned the AC on. Sure enough it worked so I have no need for a separate switch now I just use the AC switch. Don't know if it will work on your '92 or not but it may be worth a shot to try it. Of coarse your sh@t out of luck if you need the inside cooling at the same time.

 

Here is a link to my post.
first asking about the switch thaen down a little I posted my pics of my completed switch.

I like being able to use the switch when the temps go up keeping them below205 most of the time

http://forums.corvetteforum.com/c4-t...d-to-know.html

 

You wanna come see my nice green coolant your welcome to, I know there meant to run hot, reverse coolant flow and all , I was just asking a question not asking someone how to service my car.

 

Nice idea!

 

A lot of people don't like to run there car hot.
A manual switch or a low temp switch gives them piece of mind.
There is nothing wrong with wanting your car to run cooler.
I did it because I don't want to warp my heads if it gets too hot.

 

Thank you.

 

Ahhh.......I'm not convinced that they "Are meant to run hot"

There is not a single Engineering practice whereas heat is preferred.

Heat is used to make things react and to "Age" things.......So yeah....Go with the "group think" that is just supposed to run hotter than 230° in stop and go traffic.

Funny how I used to believe it just like you do Kimmer.....then I addressed ~20 year old components. Lo! the thing never gets above 220° even on the hottest days. After I did all the "Maintenance" I had to go back and replace the 185° thermostat 'cause mine ran too cool......

But go ahead and keep believing that GM engineered in a process whereas premature aging would be a certainty......

 

Here is mine on a 90° day in city traffic


Here it is a few miles later after I took an on ramp



Only the Thermostat stopps it from going lower

 

GM relied on the car moving over 35 mph to keep the C4 coolant temp at the opening temp of the factory thermostat, 195 for early C4's. They programmed the ECM to turn on the main fan at 228 F and turn off at 210 F and to turn on the auxilliary fan if it has one at 230 F. GM states to turn off the engine at 260 F and let it cool down. Even at 260 F, the temperature isn't high enough to do anything to any component inside the engine. Your fear of warped aluminum heads is totally unfounded. Two years ago my original rad had to be replaced and after repair we let it idle and the coolant temp went to 228, the fan came on and the coolant went down to 210 and the fan stopped and it repeated this cycle. I believe GM says to turn off the engine at 260 because 50% glycol at 15 psi boils at 265 F and when coolant boils its ability to carry heat is greatly diminished and you could warp a head or have other serious engine problems. I drive my 87 vette every day and have done so in every kind of weather for 21 years now and I have never seen 260 F!
I have owned a 64, 69, and a 74 vette, all had mechanical fans, a large radiator and 180 F thermostats and the cooling system stayed at 180 F all the time. Most cars in this era had the same setup, so with this experience, you expect it to be the same on your C4's. It isn't going to happen! Running at 195 F, you get better gas mileage, more HP, lower emmisions. The fact that at stoplights your coolant goes to 230 F is something you should get used to because it is not harmful at all to your engine and is how GM designed the cooling system to work. GM is responsible for warranty repair and they certainly aren't going to put themselves in a situation where they have to perform expensive warranty repairs from overheating. A good friend who has been doing Corvette repair for GM for a long time told me that he has to explain to customers to leave the C4 cooling system alone and that he has never experienced repairs due to coolant temps. My personal experience with my 87, driving it everyday in mostly city traffic and 235k miles is proof. I know several C4 owners and none has ever had a repair due to coolant temps.
As Bugs Bunny says, "Unlax Doc". 230F is a nothing for C4's.