OK So I believe I tried all the fixes to eliminate the DRL in my 2001 ZR2. The yellow wire under the floor mat; Still came on. The #86 on the DRL relay; Still came on. Disconnected the sensor in the right speaker housing on the dash and inserted resistors; Still come on. However, they are delayed until I actually put it in gear with that one. What am I missing here?

 

What behavior are you experiencing and what behavior are you getting?

George

 

If your Blazer was manufactured in Canada, there might not be a way to disable the DRL system built in to the BCM. If I remember correctly there was a way to disable the DRL by depressing the dome light override button several times. This never worked on my Canadian built 99.

I made, but have not installed a by-pass circuit to disable the selectively.

 

Hello again George. As far as the ABS light, no symptoms other than the intermittent light on the instrument cluster. The air bag light is also intermittent but no other symptoms. The brake light went out after I actually drove the thing after working on it for 2 months and does come on if I depress the e-brake. The DRL are just a nuisance and I want to get rid of them. (The override push button does work but it is just a pita to me.) I was using the e-brake in a partial mode to disable the DRL but as slight as it was I think it was wearing the shoes down as after a few thousand miles i would have no e-brake at all.

There is a local automotive electrical wiz in my town and am hoping he can shed some light on the subject.

 

So still monkeying with the DRL problem. The problem being I want it permanently disabled. This part does not make sense: Even when I take out the DRL relay, they still come on in Drive. WTF?

 

I'm sure you've probably already read through this, but this old discussion thread on disabling the daytime running lights system may help.

FYI, putting a resistor on the wires under the right dash speaker grill will only affect the auto-headlights system. It will do nothing for the daytime running lights system.

There are multiple possible vehicle configurations depending on the year, and place of manufacture, which makes it really frustrating and complicated when trying to modify how it works.

Good luck to you. I hope you find a solution.

 

Years ago I made the diagram below based on the schematics in my 1999 GM service manual to try to understand the DRL system so that I could create a DRL override circuit and also select just the fog lights to come on.

It has been a while since I've examined it, but after looking at it, it appears that if you snip off the proper pin on the HDLP GND relay so that the coil cannot be grounded, irrespective of the status of the DRL REQ switch in the BCM, the DRL system will never come on since the coils for activating the HDLP GND and DRL relays will stay in their default unenergized, manual headlight control, state.

 

Will mess around a little with this and give it a shot...

 

Back to you again George. Still no luck with DRL deletion. My symptoms are DRL comes on when in gear. (automatic trans) with key on. (2001 ZR2) Even when I pull the DRL relay under the hood they stay on. (And the head lights work also.) Christine mentioned deleting a pin on the "Head light ground relay" under the dash but I have not gotten to that yet. I am guessing it would be the ground pin? I have included a photo and schematic

from this site and Christines schematics. Any thoughts there?


I still don't understand why the DRL's would work with the under hood relay pulled. The local electrical guru is a busy guy and has been trying to help me pin stuff down but that got him shaking his head. He's a busy guy at the moment...

 

I’m out of town traveling, but I’ll be back tomorrow around noon so I’ll take a look at this in the afternoon and get back with you.

George