On my 1997 Nissan Pathfinder, I have to tap into 6 wires on a wiring harness that I believe is between 18-22 gauge. I'm planning on using wire t-taps since the wiring is up under the dash area behind the glove compartment. It would be very difficult to try and solder each wire, that's why I am going this route as it's convenient, easily accessible, and will probably save me from having a hot solder gun fall on my face by accident.
As long as the appropriate wiring tap size is used, is this a reliable safe connection?
The six wires being tapped from the harness are a speed sensor, ground, illumination, ignition, and two wires for the air temp sensor.
No. "T-taps" or "Scotch locks" are notoriously unreliable. They do not last.
You will notice that NONE of the wiring that comes from the factory is soldered. Why? Because it breaks. It does not hold up in high-vibration applications. Crimping and locking wire-to-wire connectors are the correct way to join automotive wires. Or solderless screw terminals if you must.
I have used lever nuts and they work just great. No soldering and no crimping.
Those Wago connectors are great. They're very pricey, but easy to use and you can get mounting brackets for them too.
Just curious but why are you tapping into these wires to begin with??
I decided to spend the extra time and effort and just solder. And the luxury edition model to my Pathfinder had an interior overhead console that had a screen with a temperature display and compass. My sport edition was already wired up for it but did not have the console. Just a basic one with light buttons and moonroof controls.
I got one from someone free of cost in like-new condition but did not have the harness that goes from the plug under the dash to the overhead console. And running a harness that has plug ends through the roof above the panel would be extremely difficult. So I just ran a conduit wire that had the six individual wires needed through the roof and hardwired it.
Working as it should so far.