88 GTA Fan on at Key on
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Joined: Dec 2021
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From: Southern Indiana
Car: 1988 Pontiac Trans Am GTA
Engine: 355 TPI w/AFR 195s Dyno Don Headers
Transmission: 700R4
Axle/Gears: Borg Warner 9 Bolt, 3.27 gears
88 GTA Fan on at Key on
88 GTA new 355 engine. LS fan assembly with stock wire harness. Not started engine yet but was doing an IAC cal. I go to key on and the drivers side fan is on. I put a new fan switch (goes between cylinders 6 & 8). Is it possible the new switch is bad causing it to ground causing fan to come on?
Last edited by hessm70; Mar 5, 2025 at 05:34 PM.
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From: WA
Car: 1989 IROC-Z
Engine: L98 350 TPI
Transmission: 700R4
Axle/Gears: BW 9 Bolt / 2.77 Posi
Re: 88 GTA Fan on at Key on
Fan switches come in normally open and normally closed flavors. You may have the opposite of what you need.
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Member



Joined: Dec 2021
Posts: 224
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From: Southern Indiana
Car: 1988 Pontiac Trans Am GTA
Engine: 355 TPI w/AFR 195s Dyno Don Headers
Transmission: 700R4
Axle/Gears: Borg Warner 9 Bolt, 3.27 gears
Re: 88 GTA Fan on at Key on
Thanks Komet! I thought all were ground is on so let me check that.
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Member



Joined: Dec 2021
Posts: 224
Likes: 45
From: Southern Indiana
Car: 1988 Pontiac Trans Am GTA
Engine: 355 TPI w/AFR 195s Dyno Don Headers
Transmission: 700R4
Axle/Gears: Borg Warner 9 Bolt, 3.27 gears
Re: 88 GTA Fan on at Key on
So switch is Summit SUM-8901117 supposed to be on at 185deg/ off 175.
ok unplugged switch, fan still runs so may be something else.
ok unplugged switch, fan still runs so may be something else.
Last edited by hessm70; Mar 5, 2025 at 06:02 PM.
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Member



Joined: Dec 2021
Posts: 224
Likes: 45
From: Southern Indiana
Car: 1988 Pontiac Trans Am GTA
Engine: 355 TPI w/AFR 195s Dyno Don Headers
Transmission: 700R4
Axle/Gears: Borg Warner 9 Bolt, 3.27 gears
Re: 88 GTA Fan on at Key on
@Tuned Performance thinks it may be in the a/c pressure switch setting so hes checking the tune.
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From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 88 GTA Fan on at Key on
Just checked, old tune and new tune have n/o fan switch selected. I’m wondering if the tune is bad on the chip or bad chip on the adapter.
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Member



Joined: Dec 2021
Posts: 224
Likes: 45
From: Southern Indiana
Car: 1988 Pontiac Trans Am GTA
Engine: 355 TPI w/AFR 195s Dyno Don Headers
Transmission: 700R4
Axle/Gears: Borg Warner 9 Bolt, 3.27 gears
Re: 88 GTA Fan on at Key on
Were still chasing this. So install just memcal and the fan does not come on. @Tuned Performance suggested reflashing start up tune so did that. Reinstalled and again fan on with key on.
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Joined: Dec 2021
Posts: 224
Likes: 45
From: Southern Indiana
Car: 1988 Pontiac Trans Am GTA
Engine: 355 TPI w/AFR 195s Dyno Don Headers
Transmission: 700R4
Axle/Gears: Borg Warner 9 Bolt, 3.27 gears
Re: 88 GTA Fan on at Key on
Update- I installed an old chip I had from @Tuned Performance and the fan did not come on at key on. @Reddragon88gta suggests its a Bin stacking issue so hopefully we can get it sorted. I want to get my new engine fired.
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