"There's not much to it, r
"There's not much to it, really. First you'll remove your existing electrical sending unit from the engine, then install the compression fitting from the gauge kit in that hole. The hole is usually 1/8" NPT. If the hole in the engine is larger than that use the proper adaptor fitting that will also be included in the gauge kit. Next you'll connect the thin tubing from the kit to the fitting you just installed on the engine with a compression nut and a ferrule from the kit. Route the tubing to the spot where you want the gauge, leaving a little slack at the engine to allow for engine movement, so the tubing will not be pulled loose or broken. You can either permanently mount the gauge in dash or temporarily mount the gauge underneath the dash with the bracket included with the gauge. The latter would be my choice for troubleshooting. If your existing electric gauge is faulty you can remove it, then go back and mount your mechanical gauge in the existing hole in your dash. However you decide to mount the gauge, your last step is to connect the tubing to the fitting on the back of the gauge in the same manner as to the engine fitting. It really isn't as difficult as it may sound, and your gauge kit will have complete instructions with diagrams. You can find these kits at any auto parts store for $15-$20. I hope this was helpful."