C4 manual fan switch
Thread Starter
Racer
Joined: Dec 2010
Posts: 302
Likes: 0
From: delancey new york
C4 manual fan switch
1987 C4. I know these cooling fans are set to come on at 228 and they've been running like this for more then a 1/4 centry, but i'd feel alot better if i had a manual fan switch even if i never use it, but it will be there. MUST BE MY AGE--Where is the best place to wire a switch in with-out causing any electrical problems???
Team Owner
Joined: Jan 2003
Posts: 20,306
Likes: 242
From: Summerland B.C. Canada
1987 C4. I know these cooling fans are set to come on at 228 and they've been running like this for more then a 1/4 centry, but i'd feel alot better if i had a manual fan switch even if i never use it, but it will be there. MUST BE MY AGE--Where is the best place to wire a switch in with-out causing any electrical problems???
Team Owner
Joined: Jan 2003
Posts: 20,306
Likes: 242
From: Summerland B.C. Canada
Splice into dark green wire at main fan relay and run it into cockpit. Other side of switch goes to ground.
I have my antenna switch in the panel beside the ALDL connector. That would be a good spot for a fan switch, since you don't see it.
I have my antenna switch in the panel beside the ALDL connector. That would be a good spot for a fan switch, since you don't see it.
Burning Brakes
Joined: Aug 2010
Posts: 951
Likes: 3
From: Placerville CA
Might be overkill, but I put in two switches, one for each fan, on my '94. It's not much more work since the hardest part is feeding the wires through the firewall and finding a good place to mount the switches. Both switches can share the same ground wire.
On the '94 you tap into the dark green and dark blue wires at the relays. Don't know if it's the same for older cars.
On the '94 you tap into the dark green and dark blue wires at the relays. Don't know if it's the same for older cars.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
That will work.I run the same deal as mentioned above....I just don't use an extra "switch". I tap into the same green wire as mentined above but I just grounded it to one of the brake booster studs - this way the fans run all the time when the ignition key is "on".......remove the added extra length of wire from the booster stud and your back to letting the computer switch the fan "on" and "off". The stock thermostat (195) will control the coolant's flow....expect ~ 205-235 degrees as the norm in hot weather. It wouldn't hurt to change your 20+ year old main fan relay either.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Intermediate
Joined: Jul 2021
Posts: 27
Likes: 0
From: Paragould, Arkansas
C4 vette
I need to hook my secondary cooling fan to a toggle switch. I have no experience with this . could someone please walk me thru it? What wire to tap into and where etc.
thanks all
Kevin C-4
thanks all
Kevin C-4
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Aux fan
On my 86, i found the power wire for the main fan, crimped a wire on to that (and soldered it) and used that wire to power a relay coil (since the current draw is 1/4 amp or less) mounted a relay to the long screw on the power steering reservoir clamp, ran a wire to the terminal junction behind the battery to the relay for power, using a 10 amp fuse, that wire to aux fan, then grounded neg side of relay coil.
so when main fan turns on, the aux fan comes on too. It cools down faster, and at the 25 mph fan kick on, its cooler.
also air conditioning is cooler because it has a fan blowing directly on it.
so when main fan turns on, the aux fan comes on too. It cools down faster, and at the 25 mph fan kick on, its cooler.
also air conditioning is cooler because it has a fan blowing directly on it.
Last edited by coupeguy2001; Jul 21, 2021 at 11:43 AM.
Safety Car
Joined: Aug 2013
Posts: 4,427
Likes: 604
From: Minneapolis Mn
PS all I have is the one fan if that makes any difference to anyone.
Last edited by hcbph; Jul 23, 2021 at 08:35 PM.
