ZR-1 Net Registry Forums  

Go Back   ZR-1 Net Registry Forums > C4 ZR-1 > C4 ZR-1 Technical Postings

Reply
 
Thread Tools Display Modes
Old 07-04-2020   #1
LGAFF
 
LGAFF's Avatar
 
Join Date: Mar 2007
Location: Crystal Lake, IL
Posts: 7,194
Default Fans on when ignition in accessory position

I have an issue with the fans turning on once the ignition switch is turned into the accessory position, as in supplying power, but the car is not running. I have reset the prom multiple times and even replaced the prom. disconnected the temp switch on the inj housing, and even trying jumpering the AC high pressure line switch

Thoughts, I think the only other potential issue is ECM?
__________________
LGAFF
90 #966-150K miles-sold
92 #234-sold
1987 Callaway TT #17
1991 ZR-1 #1359
LGAFF is offline   Reply With Quote
Old 07-04-2020   #2
BigJohn
 
BigJohn's Avatar
 
Join Date: Feb 2012
Location: Ledyard,CT
Posts: 8,075
Default Re: Fans on when ignition in accessory position

Is the engine warm?
BigJohn is offline   Reply With Quote
Old 07-04-2020   #3
LGAFF
 
LGAFF's Avatar
 
Join Date: Mar 2007
Location: Crystal Lake, IL
Posts: 7,194
Default Re: Fans on when ignition in accessory position

No this is from the moment you turn on the switch, even when dead cold
__________________
LGAFF
90 #966-150K miles-sold
92 #234-sold
1987 Callaway TT #17
1991 ZR-1 #1359
LGAFF is offline   Reply With Quote
Old 07-04-2020   #4
LGAFF
 
LGAFF's Avatar
 
Join Date: Mar 2007
Location: Crystal Lake, IL
Posts: 7,194
Default Re: Fans on when ignition in accessory position

I should probably mention its only the primary fan... and I did swap relays with same result
__________________
LGAFF
90 #966-150K miles-sold
92 #234-sold
1987 Callaway TT #17
1991 ZR-1 #1359
LGAFF is offline   Reply With Quote
Old 07-04-2020   #5
Corvette95
 
Corvette95's Avatar
 
Join Date: Jan 2006
Location: Decatur, AL
Posts: 1,107
Default Re: Fans on when ignition in accessory position

Check if your A/C pressure switch is unplugged or bad. (on high side line with red upper body)
__________________
Corvette95 Registry and Forum (*************)
1989 C4 Conv Wht/Gry Auto Hardtop Top Flight SOLD
1995 C4 Coupe Purple/Blk 6 Speed
1989 C4 Conv Wht/Red Auto SOLD
1996 C4 Conv Black/Tan Auto SOLD
1994 C4 Coupe Wht/Blk SOLD
1995 C4 ZR-1 White/Gry #278 Dual Dunn Head SOLD
1986 C4 Coupe Black/Red 4+3 SOLD
1990 C4 ZR-1 Red/Red #0454
Corvette95 is offline   Reply With Quote
Old 07-04-2020   #6
LGAFF
 
LGAFF's Avatar
 
Join Date: Mar 2007
Location: Crystal Lake, IL
Posts: 7,194
Default Re: Fans on when ignition in accessory position

Quote:
Originally Posted by Corvette95 View Post
Check if your A/C pressure switch is unplugged or bad. (on high side line with red upper body)

I jumpered the connector ..... didnt change anything, also does the car have to be running to turn it on due to the pressure switch.... this happens on mine in accessory mode
__________________
LGAFF
90 #966-150K miles-sold
92 #234-sold
1987 Callaway TT #17
1991 ZR-1 #1359
LGAFF is offline   Reply With Quote
Old 07-04-2020   #7
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,696
Default Re: Fans on when ignition in accessory position

So Lee, with ignition ON but not running, do fans come on?
__________________
[SIGPIC][/SIGPIC]Former Membership Chairman
Former ZR-1 Registry - BOD
1972 Corvette 4speed base Coupe SOLD long time ago
1984 Corvette Z-51/4+3 SOLD
1992 Corvette ZR-1 Aqua/Gray #474 SOLD
1992 Corvette ZR-1 Black Rose/Cognac #458
2014 Honda VFR Interceptor DX
XfireZ51 is offline   Reply With Quote
Old 07-04-2020   #8
LGAFF
 
LGAFF's Avatar
 
Join Date: Mar 2007
Location: Crystal Lake, IL
Posts: 7,194
Default Re: Fans on when ignition in accessory position

Yes engine is off and fan 1 cones on not both


Sent from my iPhone using ZR-1 Net Registry
__________________
LGAFF
90 #966-150K miles-sold
92 #234-sold
1987 Callaway TT #17
1991 ZR-1 #1359
LGAFF is offline   Reply With Quote
Old 07-04-2020   #9
Corvette95
 
Corvette95's Avatar
 
Join Date: Jan 2006
Location: Decatur, AL
Posts: 1,107
Default Re: Fans on when ignition in accessory position

Quote:
Originally Posted by LGAFF View Post
I jumpered the connector ..... didnt change anything, also does the car have to be running to turn it on due to the pressure switch.... this happens on mine in accessory mode
If the connector is bad or unplugged the fans will run all the time. I am not sure if jumping it will work or if it is a resistance number it is looking for.
__________________
Corvette95 Registry and Forum (*************)
1989 C4 Conv Wht/Gry Auto Hardtop Top Flight SOLD
1995 C4 Coupe Purple/Blk 6 Speed
1989 C4 Conv Wht/Red Auto SOLD
1996 C4 Conv Black/Tan Auto SOLD
1994 C4 Coupe Wht/Blk SOLD
1995 C4 ZR-1 White/Gry #278 Dual Dunn Head SOLD
1986 C4 Coupe Black/Red 4+3 SOLD
1990 C4 ZR-1 Red/Red #0454

Last edited by Corvette95; 07-04-2020 at 01:04 PM.
Corvette95 is offline   Reply With Quote
Old 07-04-2020   #10
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,696
Default Re: Fans on when ignition in accessory position

Quote:
Originally Posted by LGAFF View Post
Yes engine is off and fan 1 cones on not both


Sent from my iPhone using ZR-1 Net Registry
Is this a new calibration u put in, or has the prom always been there and now this is happening? Does SES flash once on initial ignition ON?
__________________
[SIGPIC][/SIGPIC]Former Membership Chairman
Former ZR-1 Registry - BOD
1972 Corvette 4speed base Coupe SOLD long time ago
1984 Corvette Z-51/4+3 SOLD
1992 Corvette ZR-1 Aqua/Gray #474 SOLD
1992 Corvette ZR-1 Black Rose/Cognac #458
2014 Honda VFR Interceptor DX
XfireZ51 is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:19 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright ZR-1 Net Registry 2020