coolant fan switch location

[thirdtimevetteowner]

I hate to run this into the ground, but I was reading a Haines manual today and it showed the coolant fan switch on the front of the intake manifold. I tried to find it, w/out success because there is too much stuff there to see anything. Is this the right location? I want to install a Hypertech fan switch but can not get the pipe plug between cylinders 1 and 3 out. I ordered a tool, but found out today it is back-ordered. Anyway, if the book is correct, couldn't the Hypertech switch be put there? I already installed a 160* thermostat, and am thinking of buying the cooresponding chip but am growing tired of this project already. Any insight on this would be appreciated, as always. TIA.

Rich K

P.S. Even if I finally do get this switch put in, it programs the fan to come on at 176*, and go off at 166*. That sounds impossible to me, especially since my car does not have the aux. fan.

 

[Dougs91]

Rich- why not just go with one of those aux. fan switchs that wire right into your fan relay? I did this to my 91 and can just flip a switch inside the cabin anytime I want. I looked at those those Hypertech things,and went with the above from Mid-America I think for like under $20.00.Tap into the relay and Bam! your in control. Just my .02cents Good Luck!! Doug

 

[tigmaned]

i was wondering about my fans. they seem to me to be on all the time, i have to check it after she has sat all night and first start her up for sure, and look at what temp they come on? when i got my 86 it was leaking a little at the stat housing so i figured since i didn't know if or when it had been changed last, get a new one which the parts guy said it calls for a 195 so i put it in. my vette the very first thing in the morning goes to almost 190 then goes back down (i am sure after the stat opens) to 175 to 180 and stays there. so dose this mean my 195 stat is opening and closeing since the fans are keeping it cooler then 195 all the time. the last owner had to put a new rad in, he said the old one blew out. so i can see having a new rad being nice and clean helping with cooling, but should i change the fans to come on at some temp or change the stat to 180. or let it alone since its working? after driving when i stop some times i get out and feel the top hose and it feels like its under pressure.

 

[Baldie88]

Your 89 may be like my 88 and I did replace the coolant temp. switch. I think I got it from MAD. Anyway I think its a green wire running to a pin on the switch and the switch is between 1 and 3 on the block, not the intake manifold. Can't remember the socket size but is was a regular socket I had, no special tool. Got to be quick because you'll lose a little coolant but it was pretty much a no brainer. However the switch I got controls the aux fan which you say you don't have. The switch I got comes on at 180 and since I've got a 195 thermostat it pretty much runs all the time.

Even with this aux fan running I still get pretty hot without any airflow through the radiator. Was in a parade a couple weeks ago, temp about 80. I could hear the aux fan running but the car temp still got to 220 a couple of times. Ended up running the ac with the windows down and top off. Oh well. Anyway with this switch in normal highway driving I usually hold right around 190.

Don't know if this helps but that's the way mine operates.

Ron
"Baldie88"

 

[Baldie88]

Found it!

After I answered I remembered I had the latest MAD catalog at work. The coolant switch I bought is found on page 45. I bought just the switch (part number 609-106) since I already had the aux fan. There is a harness (part number 609-108) that is required for single fans which is what you have. You can probably use these numbers to check on-line if you don't have the catalog. Switch turns on fan at 200 and off at 185.

Hope this helps.

Ron
"Baldie88"

 

[tigmaned]

baldie88

still got the same old 1988 rad? or cleaned out between the condensor and rad laterly. my new rad was only in 6 months and i pulled the top rad cover and found about 3-4 inchs or leafs, pin niddles and other junk in there. i also have a 195 stat and my fans come on early too, but i never see over 195. even check it with a fulke temp laser gun.

 

[Baldie88]

tigmaned,

Yes I've still got the old radiator and haven't cleaned it out. The radiator itself has been flushed out and I don't worry much about the temp as long as I'm moving. As soon as I switched on the ac during the parade the temp went right back down to 195 so I think the fins, etc. are pretty clean. Just turned 40K on it so shouldn't have too many leaves and things in it. I'm planning on pulling the rad. and doing a good cleaning, just haven't gotten to it. Building a new house has been my priority lately. But based on what you found it may be one of my first project once I get it back in a garage. And it's an oversized 3-car garage!

Regards,

Ron
"Baldie88"

 

[tigmaned]

only 50K boy that nice low mileage!! i wonder if a vette that seats more would cause more stuff to build up in the rad then one thats driven more? do 1988 models have 2 cooling fans? my 1986 only has one. you said you turn the air on, which yes i know kicks the fan on. but did GM change the design on fan for the temp part and one for when the A/C is on?

 

[thirdtimevetteowner]

I think I will go with Dougs91 idea and just put in a switch. I am thinking my fan may be on all the time with the Hypertech 160* stat and switch that comes on at 176* and goes off at 166*. Besides, I also think those temps may be too cold for it to run right, unless I buy the Thermomaster chip to go with them. Anyone running the Thermomaster setup? TIA

Rich K

 

[Hrtbeat1]

Thirdtime

I replaced my sensor when I first got my car. I used the Hypertech switch and it seems like I remember it being located on the passenger side between the middle two cylinders on the block. I used a standard deep socket (3/4? maybe) to remove and install.

The coolant temp sensor that you were refering to on the intake manifold is just left and lower from the thermostat housing neck. Its really hard to get to with the AIR pump stuff in the way. It should be a three wire connector, small and plugs into the sensor. This one is used to give the coolant temp to the ECM and the display on the dash. I think the Haynes manual is incorrect in saying it is for the fan / fans.

FWIW the same part number / same sensor is used for the engine oil temp. It is located just above the oil filter if you have the engine oil cooler as a stock item. May be the same location without the cooler, not sure.

 

[ecss]

I can re-program your chip so the fan turns on earlier at no charge.

You would have to mail me the chip carrier which has the E-prom soldered on it. Of course your car will be down for a couple of days.

I have my main fan turn at 205 and off at 195.

PM me if you're interested.