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Negative side of coil?

This is a discussion on Negative side of coil? within the Technical / Maintenance forums, part of the General Discussion category; I have a 1990 C1500 305 with no factory tach that I wan't too put a aftermarket one in and ...

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    Negative side of coil?


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    I have a 1990 C1500 305 with no factory tach that I wan't too put a aftermarket one in and I'm confused as too where the negative side of the coil is. Because there is no terminal like the old external coil's and the book say's there's 2 lives going in and it's grounded from the motor. How or where would I find where too hook the tach wire up?

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    Diesel Nut justy's Avatar
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    Re: Negative side of coil?

    I think on some chevys, if you look at the distributor there's a brown wire hanging loose. Seems to me that was used for a tach.
    Last edited by justy; 11-30-2008 at 10:53 AM.
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    Re: Negative side of coil?

    The tach signal wire should be connected to the tach terminal on the distributor cap. On your distributor cap, locate the place where the electrical plug attaches. You will see that the plug attaches to the back pair of terminals on the cap that feed the ignition coil inside the cap. There are 2 other terminals in this same area; connect the tach wire to the one on the left front. You may need to take the cap off and turn it over to see these terminals.
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    Re: Negative side of coil?

    go here for wiring diagram:

    http://www.fullsizechevy.com/forums/...3&d=1206741675
    pink wire is from ignition.
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    Supporting Gold Member GreaseDog's Avatar
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    Re: Negative side of coil?

    Quote Originally Posted by mnstrjim
    The tach signal wire should be connected to the tach terminal on the distributor cap. On your distributor cap, locate the place where the electrical plug attaches. You will see that the plug attaches to the back pair of terminals on the cap that feed the ignition coil inside the cap. There are 2 other terminals in this same area; connect the tach wire to the one on the left front. You may need to take the cap off and turn it over to see these terminals.
    he has small cap remote mounted coil HEI, this info wont help him any. its for big cap, in cap mounted coil.
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    Re: Negative side of coil?

    That's my problem.

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    Re: Negative side of coil?

    there is a wire in the harness somewhere...that is a white wire with a connector on the end..that doesnt go anywhere its the tach test spot..use it.

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    Re: Negative side of coil?

    Thank's for the info I'll look for it when I get time sorry for the late reply I couldn't get too a coumputer for a while.

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    Re: Negative side of coil?

    I couldn't find a tach lead for my 02 van either. I had to locate the negative coil wire and scotch-lock to it. I installed 2-1/16 inch Nordskog digital tach and tranny temp guages.

 

 

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