Where to install temp probe for rear view mirrow with temp display?

[EUREKA]

I bought a new rear-view that has compass and temp display, but I'm not sure where I should mount the temp probe. I was thinking under the balance in the area with the wiper arms. Does that sound reasonable? I don't know where newer cars have them. I think I'm going to install the temp probe in the grill, but I'm not sure how I should run the wires through the firewall. Or where I should get 12 volts that is only on when the ignition is on.

[jdog]

Most new cars are behind the front bumper or behind the grill

[fiatslug87]

Our era Cherokees had them behind the front bumper in the center on the front body panel. I put mine near the air intake so I know the air temp the engine is getting.

[schardein]

I mounted the temp probe behind the front bumper using an existing screw.  Seems to be fairly accurate.

[schardein]

You can tap into the fuse box for the power wire.  You probably have two options, see pic.  The IGN should be hot with key on, and the ACC should be hot with key in the RUN or ACC position. 

You can tap into these ports with a simple 1/4" wide male spade connector.

Or, if you can do it like the factory did, using a plastic connector that is keyed to the specific location and locks in place so it can't be accidentally pulled out.  Here is a source for the plastic connectors and terminals.  The IGN port uses a brown connector, and the ACC port uses a green connector.

https://www.ebay.com/itm/333919030216?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=bpFa1QANQb2&sssrc=2380676&ssuid=bpFa1QANQb2&widget_ver=artemis&media=COPY

[EUREKA]

Thanks schardein !

[EUREKA]

Got it all wired up, now I just have to figure out how to shove my a-pillar trim back in between the dash and the body.

[schardein]

5 hours ago, EUREKA said:

Got it all wired up, now I just have to figure out how to shove my a-pillar trim back in between the dash and the body.

You're welcome and yes that can be a tight fit