low temp fan switch
Thread Starter
Instructor
Joined: Jan 2013
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low temp fan switch
it cant be this easy
http://www.summitracing.com/parts/hy...model/corvette
my car has erratic fan operation. sometimes its perfect and they turn on at 226, other times they never turn on and i overheat and either have to stop driving or get on the parkway and do 80. i always thought the computer is what controlled fan operation. will this simple fan switch cure my problems? i would like this thing to run cooler. i will also be investing in a low temp stat (i dont even have my stat in right now).
http://www.summitracing.com/parts/hy...model/corvette
my car has erratic fan operation. sometimes its perfect and they turn on at 226, other times they never turn on and i overheat and either have to stop driving or get on the parkway and do 80. i always thought the computer is what controlled fan operation. will this simple fan switch cure my problems? i would like this thing to run cooler. i will also be investing in a low temp stat (i dont even have my stat in right now).
Thread Starter
Instructor
Joined: Jan 2013
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did some more research. whats the difference between the hypertech and this:
http://www.ecklerscorvette.com/corve...1984-1995.html
?
http://www.ecklerscorvette.com/corve...1984-1995.html
?
Safety Car
Joined: Jan 2006
Posts: 3,940
Likes: 42
From: shavertown Pa.
It's very easy to do the hardest thing to do is get the plug out of the head on the drivers side between the first two spark plugs.
The plug has a square hole in it, what fits the hole perfectly is a swivel tipped 3/8" extension.
All you need to do is get the plug out screw in the new unit and connect the wire to the ground on the fan relay, if you want to run 2 fans just connect the 2 fan grounds and it will operate the fans or fan if you wish.
The computer never sees it so no codes, a very worth while investment.
BTW you don't need to buy the wire harness, just use a butt connector it plugs right on to the post on the new switch.
The plug has a square hole in it, what fits the hole perfectly is a swivel tipped 3/8" extension.
All you need to do is get the plug out screw in the new unit and connect the wire to the ground on the fan relay, if you want to run 2 fans just connect the 2 fan grounds and it will operate the fans or fan if you wish.
The computer never sees it so no codes, a very worth while investment.
BTW you don't need to buy the wire harness, just use a butt connector it plugs right on to the post on the new switch.
Drifting
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
There is a wire coming from pin C1 of your ECM:
http://www.chevythunder.com/fuel%20i...ts.htm#1986-89 pinouts (ecm #1227165)
If you connect it to the fan switch you linked it will work. You can also have someone reprogram your memcal.
What bothers me is the intermittent issue your are having. You should replace the fan relay, and check the conductors for continuity.
http://www.chevythunder.com/fuel%20i...ts.htm#1986-89 pinouts (ecm #1227165)
If you connect it to the fan switch you linked it will work. You can also have someone reprogram your memcal.
What bothers me is the intermittent issue your are having. You should replace the fan relay, and check the conductors for continuity.
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
Can be partially true, depending on the year. What year is the car?
Probably not. The system is set up the way it is for multiple reasons. For example, the computer turns off the fans when you go over 40 MPH. Can this switch do that?
What temperature do you see when the engine is hot (assuming the fans are operating normally)?
To address your overheating problem: It sounds like you have a bad (intermittent) connection somewhere in the fan circuits. That could be inside a relay. Another possibility is that the computer is not seeing the correct coolant temperature and therefore not turning on the fans.
To address your overheating problem: It sounds like you have a bad (intermittent) connection somewhere in the fan circuits. That could be inside a relay. Another possibility is that the computer is not seeing the correct coolant temperature and therefore not turning on the fans.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
. whats the difference between the hypertech and this:
http://www.ecklerscorvette.com/corve...1984-1995.html
?
http://www.ecklerscorvette.com/corve...1984-1995.html
?
Both are way more expensive than this (quality ) thermo switch
http://www.racerpartswholesale.com/p...n_Accessories2
that does exactly the same job
185F version also available
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
Splice the fan control wires and install thermo switch in where the DPST switch is shown in the diagram below and it will run the fan(s) at the new temp ,
but If the switch should fail ,the fans will still be turned on by the ECM at the stock temp setting
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Safety Car
Joined: Jan 2004
Posts: 3,556
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Pro
Joined: Mar 2013
Posts: 628
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From: Indiana
As stated by Vetteoz you need to get the thermostat back in the car. You need the correct one also. It is designed to maintain the correct flow rate through the radiator to get maximum cooling and cooled coolant flow through the block. It has a very specific purpose and is needed to maintain correct engine temperature.
Thread Starter
Instructor
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Uh oh...i went to take a look to see how hard its gonna be to install the new switch, and nothing is plugged into the old one!
http://imageshack.us/photo/photo/198/4oa3.jpg/
What the f*** is going on here?
http://imageshack.us/photo/photo/198/4oa3.jpg/
What the f*** is going on here?
Last edited by octaneforce; Aug 10, 2013 at 11:07 AM.
Thread Starter
Instructor
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Pro
Joined: Mar 2013
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From: Indiana
That looks like your knock sensor in the second picture. That also needs to be hooked up to stop the computer from advancing your timing to far. Without it you run the risk of damaging your engine. Some of these have one on both sides. Check to see if the other one is hooked up.
Last edited by Klyde; Aug 10, 2013 at 03:05 PM.
Pro
Joined: Mar 2013
Posts: 628
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From: Indiana
If that is your knock sensor it is needed. The computer advances the timing watching the knock sensor counts. When the counts start getting high it backs off. If it doesn't see knocks it just keeps going. This could have catastrophic results. I don't know how many knock sensors your year has. I'm hoping it has another one hooked up for safety reasons.
Safety Car
Joined: Jan 2004
Posts: 3,556
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That is the location to install a new switch ( if needed ) and wired as I showed above to operate both fans together
FWIW
The knock sensor is in the engine block on pass side above the starter.
Directly above it in the cyl head will be the sender unit for the temp gauge ( Spade terminal with green wire )
Last edited by vetteoz; Aug 10, 2013 at 05:02 PM.
Thread Starter
Instructor
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But why isnt it connected? I just sat outside for an hour with the car idling. With the a/c on, both fans are always on. When i turn the a/c off, the fans come on at 226. The fans never operate independently. Did somebody make it so the aux always turn on with the main fan? There are two relays for the fans.
http://imageshack.us/a/img541/70/1xdq.jpg
http://imageshack.us/a/img32/9799/g2n6.jpg
http://imageshack.us/a/img42/3040/r3wx.jpg
If i unplug one relay, the main turns off. If i unplug the other relay, the aux turns off
http://imageshack.us/a/img541/70/1xdq.jpg
http://imageshack.us/a/img32/9799/g2n6.jpg
http://imageshack.us/a/img42/3040/r3wx.jpg
If i unplug one relay, the main turns off. If i unplug the other relay, the aux turns off
Safety Car
Joined: Jan 2004
Posts: 3,556
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What is the meaning of life ?
Are you the orginal owner of the car?
Do you know what every owner has done to the car in last 20 years?
Only by tracing the fan wiring and comparing to the circuit diagrams in the FSM only YOU can determine how your car is NOW actually wired up
We can only speculate.
Last edited by vetteoz; Aug 11, 2013 at 02:12 AM.
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
It appears that someone has connected the auxiliary fan to the main fan, which would explain why they both come on at the same time. From your description, it's the relay coils that are connected together. That would be terminal F on the relay.