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E40 Wiring Blues

Old Oct 21, 2015 | 03:07 PM
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Howdy. Working on an E40/T42 out of a 05 GTO going into a second gen F-body. The engine wiring harness is 99.9% done and car is ready to try and start except for a couple of things. I have a circuit on the ecm and tcm called accessory voltage and I'm unsure what I should do with them. Right now they are wired in to be hot when I turn my key on, but I'm concerned that I could do damage to the computers if I have voltage at someplace where I shouldn't. Last thing I want to do is fry the computers the second I turn the key. I'm thinking about disconnecting the power to them and see if it'll start. At least I can't damage anything that way. Does anybody at all have any knowledge about this circuit as I've been researching it for a while now?
And the other thing is that when having the ecm at the tuner he told me that the cooling fans operate by PWM and that I have to use any external box to get the fans to operate. I'm thinking he's wrong and that the E40 activates a ground signal to trigger the fan relays. Anybody have E40 fan experience? Thanks, Chris.
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Old Oct 21, 2015 | 05:58 PM
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You don't need it. Leave it disconnected. Pm me your email and I can send you a spreadsheet listing the necessary pins and fan connections.
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Old Nov 29, 2015 | 08:15 PM
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Originally Posted by aknovaman
You don't need it. Leave it disconnected. Pm me your email and I can send you a spreadsheet listing the necessary pins and fan connections.
Hey thanks for the info. It's been awhile since I posted this, but after your advice and some others I did disconnect the accessory voltage circuit and the car runs. No issues with wiring at all and everything works as it should (minus the pulse wipers on the 79 trans am Haha). So thanks. I'm so glad I did this by myself and didn't have to pay anybody anything other than the computer mods.
Thanks again
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