Hi, New to this forum, I have a 1989 corvette,no B4P option(aux fan). I bought a Corvette America cooling fan switch kit which turns on the fans at 200 degrees.Where do i install the switch,do i remove the sensor between cly. 6 & 8 or do i remove the plug between 1 & 3 and install there. Thanks for any help.A couple of more questions to follow.

 

If you remove the sensor between 6 & 8, you will lose the temp read out on your dash! Your new switch goes between 1 & 3 once you’ve removed the plug.

 

[QUOTE=Ray Quayle;1595951978]If you remove the sensor between 6 & 8, you will lose the temp read out on your dash! Your new switch goes between 1 & 3 once you’ve removed the plug.[/QUOTE Thank you for the reply, i will try to remove it, looks like fun.

 

Use a high quality tool to get that plug out, one that won't break off or round out the square hole.

 

Hi, Yes that is just what i did, ordered a 8mm/ 3/8 drive socket to fit in there. And soaking it with PB Blaster, i will spray it every nite till i get the tool.
bought the car and giving it what it needs,brakes,rotors and flush,hoses,therm,etc. There was a lot of garbage,leaves a bag and a mud dubber nest the size of Texas between the rad and condenser. Cleaned it all out pressure washed everything and is running cooler but still goes up to about 238 before the fan kicks in,but that switch should remedy that.Thanks for your help.

 

What switch kit exactly did you buy from Corvette America?

An '89 C4 with the L98 engine and no (B4P) auxiliary fan can only change the main fan turn on temperature with a chip or a tune that alters the OEM ECM fan turn on settings.The main fan is controlled by the ECM it comes on when the coolant temp sensor hits ~228*F and off @ ~210*F. The Coolant Temp Sensor can be found below the thermostat housing.The main fan is turned on by the ECM based on inputs from the coolant temp sensor, vehicle speed sensor, and the A/C coolant fan switch.

If you have an auxiliary pusher fan in front of the AC condenser it is controlled by coolant temp switch found between cylinders 1 & 3 in the drivers side cylinder head. It comes on @ ~238*F and off @220*F. The aux fan temp switch between cylinders 1 and 3 shorts to ground at 238 F! This grounds the aux fan relay coil and turns the aux fan on. The ECM turns the main fan on at 228 F and off at about 210 F.

There are several temp. switches available for the aux. fan setup on an '89.
These part below numbers are for '89's equipped with an auxiliary fan and won't help you but you could install one and use one of these lower temp. turn on switches to help cooling. If you go that route and remove the plug in your cylinder head between cylinders 1 & 3. Read this thread, https://www.corvetteforum.com/forums...side-head.html

GM part # for the OEM auxillary fan switch mounted between the 1 & 3 cylinders is 14043276 (AC Delco # D1852B) This switch closes at 238*F and opens at 220*F

GM part # for a lower temp switch that closes at 215*F and opens at 200*F is 14043275 (AC Delco # D1855B)

Mid America sells an even lower auxillary fan switch that closes at 200*F and opens at 185*F, part # 609-106

 

Hi, It is kit # 40372 consisting of a switch,harness and connectors. It has instructions for the primary fan thats controlled by the ECM. Basically installing that switch between 1 and 3 cyl.(if i get the plug out) and splicing,not cutting into the dark Green and white wire at the relay,once the new switch grounds out it should turn the fan on at 200 i think the switch is set at. Isn't that what the ecm does when it reaches its set point?. should work. Thanks for that info,you know you can search the web many times and not get a straight answer to your question, thats why i joined to get some straight answers, thank you for that.
I hope this switch works, if not a bigger radiator may help. Here in Florida its kinda of cool rite now, and the overheating i dealt with last month i just know it will not make it thru next summer. May have to sell it, need reliability rite now, but i love the way it feels and drives. I also have a 1973 Pontiac grand am thats almost ready for the road. We will see.

 

Are you sure that "kit" works for the primary or main fan?
http://www.corvetteamerica.com/cf/di...ord%3A%2040372

Remember for an '89 the main fan is controlled by the ECM. That kit appears to use a temp. switch that needs to be mounted into your cylinder head (Between cylinders 1 & 3 I'll assume where you have a plug)?? That kit mentions and I quote "Conversion Harness required for installation on cars with auxiliary fan controlled by ECM" which doesn't really make any sense for an '89 C4 because the auxiliary fan isn't controlled by the ECM the main fan is!

 

Well....I'm not sure lowering the turn-on temp will "cure" any existing problem. If you haven't already, you should clean the space BETWEEN the radiator and A/C condenser. It's a COMMON source of airflow restriction.

That said, you are reading the instructions correctly. The kit you bought will add a second "trigger" (ground) for the main fan. By default, the ECM grounds the main fain RELAY to make it turn on. If you ground the relay at a lower temp, the fan will turn on sooner/lower. That's what you are doing when installing a [grounding] switch in the block...and splicing it into the main fan relay. You are providing an alternate/secondary ground for the energizing coil in the main fan relay.

NOTE: You MAY find the fan turns on EVEN LOWER than expected. I purchased JUST THE SWITCH and it turned on my main fan at 180ish. I ended up getting a refund because the fan would ALWAYS run. (They didn't make me return it...which was nice.)

I think the reason they have you splice vs replace the ground is so the main fan will STILL come on even if the mechanical (head) switch fails. But, it's also possible the ECM needs to "know" if the fan is on (by sensing ground) for proper operation of the air conditioner, high-pressure switch, etc...

(I'm only suggesting this because I never took the time to figure out how the A/C circuit works. I have little reason to believe it's true. It's just as likely that the manufacturer doesn't want to assume liability if the switch fails AND your motor burns up w/o having fan control any more?)

 

Hi, yeah i do not understand why it says that about the harness, i may call them on that. I still have to get that plug out, waiting for the socket. I only have 1 fan so i would say its the main fan. I will try it and see what happens,my concern is that the fan may run all the time. So if i do not see any improvement i will just disconnect it. I will let you know what happens, thanks.

 

Hi, Yes i did clean between the rad and condenser, lots of trash was in there and it is running cooler now, but it is cooler here so i will try that switch and see what happens, i also thought about it running all the time and if it does than i disconnect it. True about the ac, i will study the wiring diagrams just for some relaxation. Thanks for the info.

 

Mako41 is this information correct for an 85 as well?

 

I am not sure, worked on my 89 which is now sold.

 

I'm not positive as I only own and know how an '89 fans work...that being said I'm pretty sure your '85 does not work in the same way with the same parts and parameters.

 

Does your '85 have the AUX fan in front of the 'condenser'? SPID label (in storage compartment) would display RPO - V08. Your '85 has components in different locations than those mentioned. You might consider maybe a new thread after confirming your options.

 

If you are having heat issues in Florida then you might want to think about some other options.

Check to be sure that your Serpentine belt is tight and that your water pump pulley can't spin by hand. When the belt is loose the water pump is not running like it should be

Be sure that you have the spoiler under the front of the car. Frequently they get broken and are removed. YOU NEED THE SPOILER if your car does not have one, get one.

I occasionally clean the corrosion of my aluminum fins on my radiator using Home Air Conditioning "Coil Cleaner" which is sold at Home Depot. This is a mild acid (Phosphoric ?) that will clean off the aluminum fins really well. Just don't get it on painted surfaces.

I have seen several cars with high temperatures and they all had more than 50% anti-freeze. I saw one car where they filled it with straight (Un-mixed) anti freeze. Anti-freeze does not help your car in Florida other than lubricate the water pump seals. I live in Virginia and I mix it on the light side for my area, I typically use no more than 30% A/F. Your radiator cap is what helps the car operate at higher than 212 degrees.
Replace the coolant and try to use the least amount of A/F for your zone. Replace the radiator cap every five years or so. When they get older they have the potential to fail more often sometimes causing overheating.

(I lived in Abu Dhabi for a while (Summer 120-130 degrees) and there we put plain distilled water in the radiators. Water is more effective than A/F at transferring heat.) We did use good radiator caps for the pressurization of the system which raises the boiling point up to ~260*F.

If you still run hot then you might want to be sure that you have a good radiator. A good DeWitts replacement might be all it takes.

The water pump from the factory is not the greatest so if your shows any signs of leaking, replace it with a after-market water pump.

When replacing your coolant you might add a bottle or two of the REDLINE product "Water Wetter". This material helps the heat transfer out of the metal more effectively.

I have a 1968 C3 L-71 car that has a tendency to run hot (HIGH compression). It has an aluminum radiator with two fans in the shroud with each controlled by a separate control system. My controllers both ramp up the speed after hitting a specific temperature. This is much quieter and keeps my engine within a certain temperature range. My engine runs hot enough that I use a special Water-less coolant made by Evans called Non-Aqueous Propylene Glycol which really does a great job keeping the heat under control.

With a couple tricks you should be in shape to stay cool all Summer long. Good Luck and may your car always be cool!