Garmin Power Switch Control Input

TimFitz · Jul 6, 2026

Installed a Garmin Power Switch back by battery near firewall on my 2500HD Duramax. Up until now I just used the snow plow prep for power and ground.

Would like to add a control input wire from a switched source so I can set it up for backlighting to come on/off with ignition switch. Is there a good location for this switched source under the hood? I don't really like the idea of 'tapping' into wires, but think a location in the under hood fuse box (drivers side) could get me a source. What is the most professional way of doing this?

Thank you

bigc1066 · Jul 6, 2026

I used an add-a-fuse to add the ignition wire. Can’t remember what fuse I used but I’m running a 1500 with the Garmin. I can look when it stops raining here. If needed. I also found a mount for the Garmin and a negative bus bar. ( https://www.nhoverland.com/products/19-gm-1500-garmin-power-switch-mount )
Which I ordered and just waiting on delivery.

TimFitz · Jul 7, 2026

Did you get a chance to look at which fuse you used? Want to get switched power from under hood somewhere. The best part about the Power Switch is not having to push wires through the firewall.

bigc1066 · Jul 7, 2026

TimFitz said:
Did you get a chance to look at which fuse you used? Want to get switched power from under hood somewhere. The best part about the Power Switch is not having to push wires through the firewall.

No I completely forgot once it stopped raining. I will set a reminder and get it as soon as I’m off work before I drive home

bigc1066 · Jul 7, 2026

TimFitz said:
Did you get a chance to look at which fuse you used? Want to get switched power from under hood somewhere. The best part about the Power Switch is not having to push wires through the firewall.

I have fuse 46 as an add-a-fuse for the with ignition

TimFitz · Jul 8, 2026

ECM/TCM?

I was thinking about using 38 on mine which is seat fan 10a switched. If I mess something up then my a/c seats won’t work. Lol

Kwzr2 · Jul 8, 2026

bigc1066 said:
I used an add-a-fuse to add the ignition wire. Can’t remember what fuse I used but I’m running a 1500 with the Garmin. I can look when it stops raining here. If needed. I also found a mount for the Garmin and a negative bus bar. ( https://www.nhoverland.com/products/19-gm-1500-garmin-power-switch-mount )
Which I ordered and just waiting on delivery.

Thats a nice mount
I went to a fabricator and payed 200$ for a cheaper version