iroc dual fan issues
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Joined: Feb 2007
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From: SOUTHERN ALBERTA
Car: 1987 IROC-Z
Engine: 310 lb9
Transmission: SEMI STOCK 700R4
Axle/Gears: 3.45 9 BOLT
iroc dual fan issues
I just finished welding up my dual exhaust setup and i always dissconect the battery terminals when i weld on my car but when i took it for a drive yesterday and it never goes about 190 degF i have the prom programed to tunr the fan on at 170f but it never came on durning my drive. I have the secondary fan switched so i can turn it on any time, because it's not controled by the ecm. I tested all the relays and wires and the fans work. If i ground the green/white wire at the ecm the fan comes on, also my diagnostic computer says it's turned the fan on but still nothing. I switched the ecm the prom and i also dissconnected the a/c presure switch and it still wont come on. Does anyone have any suggestions? I don't mind running it off off the temp switch on the block but 230deg F is too high for my likeings and this problem is annoying me.
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Car: '91 Z28 convertible
Engine: TPI
Transmission: T5
Axle/Gears: 3.27 posi disc
Re: iroc dual fan issues
If you can turn the fan on by grounding the green/white wire on the ECM and the ECM says it's turning the fan on but the fan doesn't run, that logically leaves only one answer: bad ECM connector.
If you disconnect the harness from the ECM and ground pin E8, does the fan come on?
Lou
If you disconnect the harness from the ECM and ground pin E8, does the fan come on?
Lou
Thread Starter
Member
Joined: Feb 2007
Posts: 141
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From: SOUTHERN ALBERTA
Car: 1987 IROC-Z
Engine: 310 lb9
Transmission: SEMI STOCK 700R4
Axle/Gears: 3.45 9 BOLT
Re: iroc dual fan issues
My diagram with the pinout only lists A 1-12 B1-12 C 1-16 AND B1-16. Theres no E section on the diagram. It's MAF car on an 87' iroc-z. Could you tell me what colour wire E8 is? Also when i ground the diagnotic poort on AB terminal neither fan comes on.
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Car: '91 Z28 convertible
Engine: TPI
Transmission: T5
Axle/Gears: 3.27 posi disc
Re: iroc dual fan issues
The E8 is the green/white wire, the ECM pin that controls the primary fan relay, according to GM. Not sure if they're wrong.
Diagram here: http://www.austinthirdgen.org/mkport...ine_wiring.gif
What diagram are you going by? I'm curious how much they mis/match.
Lou
Diagram here: http://www.austinthirdgen.org/mkport...ine_wiring.gif
What diagram are you going by? I'm curious how much they mis/match.
Lou
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Car: '91 Z28 convertible
Engine: TPI
Transmission: T5
Axle/Gears: 3.27 posi disc
Re: iroc dual fan issues
After looking at the diagram closely, it might be wrong (well, go figure 
). Which pin did you find the green/white wire on?
I looked at ChevyThunder.com and it seems that the Coolant Fan Relay Control is on C1.
Btw, you mentioned 4 sections in your diagram: A, B, C and B. I believe the last one should be labeled D.
Lou
). Which pin did you find the green/white wire on?I looked at ChevyThunder.com and it seems that the Coolant Fan Relay Control is on C1.
Btw, you mentioned 4 sections in your diagram: A, B, C and B. I believe the last one should be labeled D.
Lou
Thread Starter
Member
Joined: Feb 2007
Posts: 141
Likes: 0
From: SOUTHERN ALBERTA
Car: 1987 IROC-Z
Engine: 310 lb9
Transmission: SEMI STOCK 700R4
Axle/Gears: 3.45 9 BOLT
Re: iroc dual fan issues
Ya sorry the last 1 is D, and i believe the green/ white wire is c1. also i just went for a nice drive and i left the ac pressure switch unhooked and the fan kicked on for a few momewnts but then it stopped all together. i'm thinking bad ecm ground or bad ecm connectors
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