Ambient Sensor Replacement

MarkF813 · June 26, 2011

Does anyone have an easy way to replace the DRL sensor? Or a simple way to get the top dashboard cover off?

tesnoboy · June 26, 2011

Does anyone have an easy way to replace the DRL sensor? Or a simple way to get the top dashboard cover off?

What are you trying to fix? That sensor on the dash controls the autoheadlight feature. I just had to bypass mine because my lights were on all the time regardless of sunshine. If your headlights are on, your DRLs should be out and vice versa. I have a 99 Sierra.

txab · June 26, 2011

Does anyone have an easy way to replace the DRL sensor? Or a simple way to get the top dashboard cover off?

Ambient light sensor replacement 99-02

tesnoboy · June 26, 2011

Does anyone have an easy way to replace the DRL sensor? Or a simple way to get the top dashboard cover off?

Ambient light sensor replacement 99-02

Good info! He still hasn't come back on to say what his actual problem is before he goes through all that though. Are his DRLs or his headlights that are not operating properly?

MarkF813 · June 27, 2011

Does anyone have an easy way to replace the DRL sensor? Or a simple way to get the top dashboard cover off?

What are you trying to fix? That sensor on the dash controls the autoheadlight feature. I just had to bypass mine because my lights were on all the time regardless of sunshine. If your headlights are on, your DRLs should be out and vice versa. I have a 99 Sierra.

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MarkF813 · June 27, 2011

Does anyone have an easy way to replace the DRL sensor? Or a simple way to get the top dashboard cover off?

What are you trying to fix? That sensor on the dash controls the autoheadlight feature. I just had to bypass mine because my lights were on all the time regardless of sunshine. If your headlights are on, your DRLs should be out and vice versa. I have a 99 Sierra.

Depending on what you read, the DRL/AHL sensor is called that plus the ambient light sensor. The problem is that the headlights are on all the time. I have a sensor to replace the old one, I just need to get under the top IP. I had an '89 Olds and got real good at taking off the dash after breaking a few clips the first time. The is the time I've needed to remove the dash and was looking for pointers

MarkF813 · June 27, 2011

Does anyone have an easy way to replace the DRL sensor? Or a simple way to get the top dashboard cover off?

Ambient light sensor replacement 99-02

Thanks for the step by step. I already had the same part that you showed. But the price is now up to $16. And I had the same problems. I'll let you know next week how it works out.

tesnoboy · June 27, 2011

Does anyone have an easy way to replace the DRL sensor? Or a simple way to get the top dashboard cover off?

What are you trying to fix? That sensor on the dash controls the autoheadlight feature. I just had to bypass mine because my lights were on all the time regardless of sunshine. If your headlights are on, your DRLs should be out and vice versa. I have a 99 Sierra.

Depending on what you read, the DRL/AHL sensor is called that plus the ambient light sensor. The problem is that the headlights are on all the time. I have a sensor to replace the old one, I just need to get under the top IP. I had an '89 Olds and got real good at taking off the dash after breaking a few clips the first time. The is the time I've needed to remove the dash and was looking for pointers

These are the instructions I found to fix mine. I like being able to control my lights manually. I always hated autoheadlights. A4 is the gray wire. It was really easy to do.Good luck!

To disable the auto headlights you need a 1.5K ohm resistor (Radio Shack) and 2 Scotchlok Tap Connectors (Walmart).

First locate the Body Control Module (BCM) which is under the dash, below the steering column. Laying on the floor, this should be visible without removing any dash panels. You should find a purple connector (C3). Unplug it.

Locate the white and gray wires (A4 and A6). I don't remember if white is A4 and gray is A6 or vice versa. It doesn't matter anyway. BTW - there are two gray wires in the connector. The one you want is the one farthest away from the white wire.

Tap the gray wire from the plug (C3) to one end of the resistor and the white wire to the other end. You don't need to cut the wires. Make sure you tape up all wires to prevent a short. You should now have a gray wire coming from C3 tapped to one lead of the resistor and the white wire from C3 tapped to the other resistor lead *. Plug C3 back into the BCM. Start the truck and make sure the lights are off. Throw a dark towel or something over the light sensor on the dash and verify the lights stay off. Try your light switch that has probably never been used and that's it! Takes about 5 minutes.

*You can add a switch here if you want. Just connect one end of the resistor to one of the wires in the connector (doesn't matter which one) and the other end of the resistor to one side of the switch. Then connect a wire from the other side of the switch to the other wire in the connector. This will allow you to turn Twilight Mode on and off, however there will be some delay because the bcm only checks the sensor every 30 seconds.