under dash wiring harness or a alternative way

We do not sell parts here, but if you check online, I am confident you will find a harness. That is a very popular vehicle.

If all the damaged area is between two connectors, your best bet is to find a used harness from a salvage yard. If the harness is too big to easily get to all of the many connectors, it is just as easy to run new individual wires. If that means bypassing a connector that joins two harnesses together, that is okay. Those connectors are only needed to make assembling the vehicle on the assembly line possible, and to use different harnesses for various optional equipment. The terminals in those connectors often develop a little resistance from corrosion, and that leads to heat build-up, and eventually burned terminals and melted connector bodies. Bypassing those connectors that will not be needed in the future can reduce the chances of future problems.

When you splice in a new section of wire, solder those splices, and seal them with heat-shrink tubing. Never use electrical tape. It will unravel into a gooey mess on a hot day.