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joe0508's avatar
joe0508
Explorer
Sep 11, 2013

tachometer

I own a motorhome with a 454 big block with tbi.I would like to install a tachometer to it but I cant seem to find where the tach signal goes.I installed one before but it was on a 305 and it had a terminal on the distributor that said tach signal.This one is different with no terminal like the last.Can anyone help?
  • 1995brave wrote:
    Sorry it took so long getting back, but had a family emergancy. You need to look for the white (could look tan by now) wire. It is the tach wire. Both connectors have a pink and a white wire. One goes directly to the distributor, you don't want that one. The other one the pink goes to power, when the key is ON, and the other wire is the tach and should have no wire connected to it.
    ok thanks,I will give that a try when I get back to it.I will be getting back with my results.
  • Sorry it took so long getting back, but had a family emergancy. You need to look for the white (could look tan by now) wire. It is the tach wire. Both connectors have a pink and a white wire. One goes directly to the distributor, you don't want that one. The other one the pink goes to power, when the key is ON, and the other wire is the tach and should have no wire connected to it.
  • 1995brave wrote:
    joe0508 wrote:
    The distributor and coil is separate.The coil has what looks to be two plugs on top with two wire each coming out of them.The instructions says theirs a spot on the distributor marked tach.That is the case on a 305 but not on a 454.


    Only one of the connectors should be connected. The other is for the tach. As soon as i can i'll get out to the RV and check on the wire color.
    I found a video on youtube.I think I see what your talking about.I will have to unplug the connector that plugs into the coil,then plug the tach into the plug on the coil that is not being used.Am I correct?
  • joe0508 wrote:
    The distributor and coil is separate.The coil has what looks to be two plugs on top with two wire each coming out of them.The instructions says theirs a spot on the distributor marked tach.That is the case on a 305 but not on a 454.


    Only one of the connectors should be connected. The other is for the tach. As soon as i can i'll get out to the RV and check on the wire color.
  • I hooked to the coil, the wire closest to the drivers seat (left wire looking forward).
  • The distributor and coil is separate.The coil has what looks to be two plugs on top with two wire each coming out of them.The instructions says theirs a spot on the distributor marked tach.That is the case on a 305 but not on a 454.
  • Read the instructions that come with the tach. I have never seen one that does not tell you how to interface with a GM ignition system. A lot of tach manufacturers even have adapter harnesses available to make the installation a plug and play.
    Randy
  • What year is the chassis? Do you have the seperate distributor and coil or is it all together (coil on top of the distributor cap)?
  • I just hooked to one of the wires going into the distributor. The first one I hooked to didn't work, but the second one did. I just unplugged the plug, stuck the wire into one of the connectors and plugged it back in.