My daughter has been wanting a gauge to know the outside temp for her 2002 SR5. I’m a stock/OEM kinda guy so I wasn’t wanting to modify the dash much. Here’s what I bought. It measures inside and outside temp.
IS Icstation Digital Thermometer
Amazon.com : IS Icstation Digital Thermometer, Car Auto Temperature Gauge Sensor, DC 4-28V Fahrenheit Dual Display, Monitor with 2 NTC Waterproof Probes for Aquarium Vehicle Fish Tank : Pet Supplies
I tapped the fuse box with this:
Nilight Fuse Holder Add-a-circuit Fuse TAP Adapter
Amazon.com: Nilight Fuse Holder Add-a-circuit Fuse TAP Adapter Mini ATM APM Blade Fuse Holder-10 Pack , 2 years Warranty: Automotive
The vehicle has 3 power ports on the dash, which is a lot, so I installed the gauge in place of one of the outlets. I cut the rectangular opening with a dremel. I kind of buggered up the opening because the dremel mostly melted the plastic instead of cutting. There’s probably a better way. In the space below, I installed a USB/aux port for the head unit
The I put the outside temp probe at the grill. The probe lead that came with the gauge wasn’t long enough so I spliced in some wire and ran it through the firewall with the hood latch cable and wire harness.
Here are some pics