ECM fan control not working
#1
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Car: 89 Iroc-z
Engine: 5.7 lt
Transmission: 700r4
Axle/Gears: 9 bolt
ECM fan control not working
I have a duel fan setup that i just got back up and running. the fans were hardwired in to two switches and i converted it back to the original wiring. I thought that fixing the temp sensor would fix the fans not turning on but they still dont turn on. i have the secondary fan still wired to a switch but to an A/C compressor wire that i dont use anymore. i can flip that switch and one fan turns on but the other still doesnt work. Ive hooked up a DATA logger and when i flip that switch the fan request signal turns off and when i turn the fan off the fan request turns back on but no fan spinning. I know they are wired correct what else am i missing here. thanks for any help
#2
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Re: ECM fan control not working
I would remove the relays from the socket and just jumper the socket to manually turn on the fans:
-- If this works you know your problem is with the wire from the ecm. The best way to start then is to simply get the car up to the temp the fans should turn on at and disconnect the relay and put a voltmeter on the energizing wire (wire from the ecm) to see if you have a ground signal from that wire.
--If it does not work your problem is with the power or grounding or wire to the fan. You can back probe the fan's connector to make sure you have a ground present. Also check the fan's fuse and if the relay is super old just replace it.
-- If this works you know your problem is with the wire from the ecm. The best way to start then is to simply get the car up to the temp the fans should turn on at and disconnect the relay and put a voltmeter on the energizing wire (wire from the ecm) to see if you have a ground signal from that wire.
--If it does not work your problem is with the power or grounding or wire to the fan. You can back probe the fan's connector to make sure you have a ground present. Also check the fan's fuse and if the relay is super old just replace it.
#4
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Car: 89 Iroc-z
Engine: 5.7 lt
Transmission: 700r4
Axle/Gears: 9 bolt
Re: ECM fan control not working
Sweet thanks I will have to try this once it gets warm out again. Will update with my findings.
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Car: 89 Iroc-z
Engine: 5.7 lt
Transmission: 700r4
Axle/Gears: 9 bolt
Re: ECM fan control not working
Well looks like it was the relay that went bad but now the fan stays on all the time. I guess that's not a big problem since I only drive the car when it's warm out so I guess I'll just not worry about it.