JayEstes 172 Report post Posted September 30, 2020 33 minutes ago, 1969_Mach1 said: Hope Midlife comes along with his explanation, because that makes no sense to me. Simply adding a tach wire to only the engine compartment harness? I've converted a non-tach harness for a factory tach and it involves reworking both the engine compartment and under dash harness, and much more than adding one wire. There was more done to the harness to enable tach, it’s currently unused in the dash, but the only thing that came into the engine compartment was the red “pwr” wire. I had Randy rework ALL my harnesses, and please bear in mind I need to plead some ignorance here as I have the mods in, but have not implemented them... Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted September 30, 2020 OMG. A tach power line is a RUN-only or ACC line (depends upon my mood at the time) that comes from the ignition and provides power to the aftermarket tach. The wire for the tach that I provided for the engine compartment was the tach signal line and goes to the - side of the coil. That was NOT part of the headlight harness but a wire coming out of the firewall grommet. You tied that to the starter solenoid? Nooooooo! Even if the other end wasn't tied in anywhere, I don't know what the consequences are, but it ain't good. Disconnect that wire immediately. The Tach Power line is hooked up to the ignition switch already, and goes to a pigtail for the aftermarket tach. The tach signal line also ends in a pigtail and the other end MUST go to the - side of the coil or nowhere if the tach is not used. If you are not using the tach, all three wires that go to the aftermarket tach need to be protected from shorting to each other and the chassis until they are actually used. Why didn't you contact me if you had questions about where these wires go??? Quote Share this post Link to post Share on other sites
JayEstes 172 Report post Posted October 1, 2020 (edited) Yeah. I take the blame on this one. At the time- I honestly didn’t know any better, was not thinking it thru and didn’t think about it hard enough. Weird that it didn’t give a problem from the beginning and only became an issues after years working like that. You know what they say- “life is tough- but it’s tougher if you’re stupid” Jay Edited October 7, 2020 by JayEstes typo Quote Share this post Link to post Share on other sites
