Reverse lights in towing mirror

Lon Bossom · November 19, 2017

I have a 2017 gmc Denali 2500HD with the reverse lights in the mirrors, they will not come on. The reverse lights in the tail lights work, is there a separate fuse for the mirror lights? Is there something special that I need to turn on to make these work?

42skidoox · November 19, 2017

There is a switch on the center console for the bed lights this needs to be on then they will come on if you are in reverse or park

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redwngr · November 19, 2017

^^^

The cargo light button needs to be on.

Press the switch to turn the cargo
lamp on or off. An indicator light will
turn on when the lamp is turned on,
if equipped. The shift lever must be
in P (Park) to operate the cargo
lamp. The lights on the outside
rearview mirrors turn on if the shift
lever is in R (Reverse), N (Neutral),
or P (Park).

powerhaulic · November 20, 2017

3 hours ago, redwngr said:

^^^

The cargo light button needs to be on.

Press the switch to turn the cargo
lamp on or off. An indicator light will
turn on when the lamp is turned on,
if equipped. The shift lever must be
in P (Park) to operate the cargo
lamp. The lights on the outside
rearview mirrors turn on if the shift
lever is in R (Reverse), N (Neutral),
or P (Park).

Yup, thats how they work. ;)

Waaazooo · November 26, 2017

^^^
The cargo light button needs to be on.

Press the switch to turn the cargo
lamp on or off. An indicator light will
turn on when the lamp is turned on,
if equipped. The shift lever must be
in P (Park) to operate the cargo
lamp. The lights on the outside
rearview mirrors turn on if the shift
lever is in R (Reverse), N (Neutral),
or P (Park).

The problem is they will stay on even after you lock the doors and go inside..have a beer. Watch the game, go to bed...wake up in the middle of the night to let the dog out...and look outside and see that they are still on.

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redwngr · November 26, 2017

1 hour ago, Waaazooo said:

The problem is they will stay on even after you lock the doors and go inside..have a beer. Watch the game, go to bed...wake up in the middle of the night to let the dog out...and look outside and see that they are still on.

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Supposed to shut off after 20 minutes.

2018 sierra manual:

Battery Power Protection
This feature shuts off the dome and reading lamps, if they are left on for more than 10 minutes after the ignition is turned off.

The cargo lamp shuts off after 20 minutes. This prevents the battery from running down.

Waaazooo · November 26, 2017

Supposed to shut off after 20 minutes.

2018 sierra manual:

Battery Power Protection
This feature shuts off the dome and reading lamps, if they are left on for more than 10 minutes after the ignition is turned off.
The cargo lamp shuts off after 20 minutes. This prevents the battery from running down.

Looks like I’m going back to the dealer, mine were on after 5-6 hours

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2017HD · November 26, 2017

Yeah, mine went off in about 20min - I wish there was a way to shut them off with the remote - like tie them to the lock button.

Black Denali Canada · November 26, 2017

Use a diode and have them come on automatically when shifted into reverse

I have my fogs come on with my parking lamps and Tow mirror reverse lights come on when shifted into reverse

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Waaazooo · November 26, 2017

Thanks for the pic!!! Does the direction of the diode matter?

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redwngr · November 26, 2017

1 hour ago, Waaazooo said:

Thanks for the pic!!! Does the direction of the diode matter?

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Yes!

(a diode acts like a one-way valve)

Edited November 26, 2017 by redwngr

redwngr · November 26, 2017

Thread got my curiosity up, so tried mine.

I was working near the truck so unlocked and pushed the cargo light button.

Cargo light and led's in mirrors came on.

Locked truck and keys in pocket.

Checked occasionally to verify cargo and leds were on.

After 20 minutes heard a relay click -- looked over and the lights were out.

madsen203 · October 30, 2018

On 11/26/2017 at 5:14 AM, Black Denali Canada said:

Use a diode and have them come on automatically when shifted into reverse

I have my fogs come on with my parking lamps and Tow mirror reverse lights come on when shifted into reverse

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Super helpful picture. Thank you for posting. I was wondering how some folks handles the diodes. Thank you for demonstrating install and how you connected reverse lights as well. Thumbs UP!