No DRLs

[Connorpod]

Hey Everyone!

I have a 1995 Gmt400 (Canadian Model) With DRL's. The DRL light went out the other day and was researching what is needed to replace the DRL's the forum suggested replacing the DRL module. I back ordered it in January. The problem is, I can't seem to find it's location under the dash. From what I saw in the the 1996 and up, it should be right under the dash. Anybody know where I can find its location? Also, I put in LED head light bulbs, I am not sure if that would effect the Function of the DRL module.

Cheers!

 

[Caman96]

Just replaced mine, 5 minutes tops.
Watch this video

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[Caman96]

Just a heads up, as it was pointed out to me by @someotherguy, disconnecting your battery is advisable before swapping part out.

 

[Connorpod]

I followed along the frame of the dash and was not able to find a heat shrink diode as seen in the video. The closest one that I see is near the HVAC. Could that possibly be it?

 

[GMCTruck]

I did some mods to my DRL on my 1995 GMC K1500 (Canada) a few years ago. I had to go to the local dealer and look at the electrical diagnosis book and one of the mechanics and I figured it out. At least this is how it seems to me. The 95 models use the Hi beam for the DRL. There is a DRL module (which the service manual says is behind the knee bolster but i never looked). When the lights are off, power for the DRL comes from fuse 15 and the DRL relay coil is energized by the DRL module. Power is run to the hi beams but they are in SERIES. (see red line on diagram below). When the lights are turned on, The DRL module must cut power to the DRL relay so it is not energized and the normally closed position of the relay provides a pathway to ground for the LEFT hi beam. So when the hi beams are switched on, they are run in PARALLEL. (light blue line on diagram below) I'm guessing that the DRL module must provide some voltage drop to run the hi beams dimmer. I don't know if this makes sense or not but this is the best we could figure out. This arrangement might be exclusive to the 95 year. If you replaced the hi beams with LED lights, I would think that the DRL system wouldn't work because power needs to flow the opposite direction through the left hi beam bulb and it can't because it is LED (diode).

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