TPP repro tach in 72 Skylark. Previously I had used one of these 12v positive wires to power the tach when I wired it 4 or 5 years ago (I think orange/black connector was for the clock and pink wires some sort or axcessory?). I just realized both have constant power even with ignition off. It was easy because they pushed right on the tab on the back of the tach and didnt have to run another wire. I do have a battery kill switch I use for when I know it will sit for a while. The tach stopped working, ordered a new TPP one from Todd and was wondering if the constant power might have caused the last one to fail? Should I run a separate wire from the fuse box or how/where would you get ignition only power for the tach? Thanks
If I am understanding your question correctly, the safest power source might be a dedicated wire from the fusebox, so you won't have to worry about a short/ground from any other accessory messing with the tach. I was gonna suggest using the radio's positive wire, but that would leave the tach on when the key is on "Acc."
Yes, however the clock wire has constant power because the clock would need to stay on 24/7 to keep time.
The stock tachometer did not use power. Signal wire, and ground. That's it. Just tap into a fuse that has ignition on power. Use an inline fuse on that wire, and you are good to go.
As Larry mentioned you can Run a wire from the Fuse Box if you want. Just make sure it's a "KEYED" source meaning it only comes on when the car is running. I do have a nice Tach Harness that I make for the Repro Tach's since they do require a 12 Volt Source . . . . . It uses Factory Connectors and also has the Brown Wire that is long enough to go all the way to the Coil. Be sure to Ground the Tach Housing as well!!! (All the Gauge Pods should be grounded since the Buick Dash Bezels are plastic!)
Thanks. The tach housing is grounded to the other gauges and verified a good ground there. I did have a tach harness of some sort but it's weird though. The brown wire has a fuse and went to the negative of the coil and "S" on the tach. The braided wire with eyelet (blue line in pics) was connected to the gauge mounting screws for a ground. The weird part is the brown wire routes in the center of the braided all the way to the negative of the coil while the braided part just ends a few inches from the coil with no connection... I will use one of factory connector for "ignition power" and route to the fuse box. Should I bother reconnecting the braided wire? Thanks
Honestly if it were me I would run a new wire to the Tach for the Signal. Typically these are brown but you can use whatever color you choose. No fuse or anything needed. This is simply the Tach "Signal". I would also use a new wire to be your source wire (Keyed 12 Volt) I recommend this simply because you'll know that you have new wiring and that will not be the issue that may or may not have caused an issue with your last Tach. Wire's cheap!!! .
