Assistance with Fixing ABS wire harness.

So, I got a P500 code and the speedometer is intermittent.

After diagnosing the issue, I found that this wire was cut and spliced. (Prev owner)
I can’t seem to find a wire diagram for this, but I can confirm after fiddling with it it sends signal somewhere to cluster.

I will be repairing this, but I think this is a 20 or thinner gauge wire.

Is putting a 18guage wire splice going to screw anything? IE add more resistance, or what have you?

I plan on fixing it with 2 crimp and Soder butt connectors and a 18awg wire, and heat shrink.
Or should I do something different?

 

That's the SP1 circuit, it sends the vehicle speed signal from the Skid Control ECU (ABS Module) to the Combination Meter (Instrument Cluster).

I would either solder and heatshrink it or use a heat seal butt connector, those solder seal connectors are bad about the solder joint cracking and losing connection.

 

Thank you. Was able to fix my problem.