Headlight Relay 46-HDM Melted

[d-wreck08]

So after driving into work this morning, 15 minute trip, after turning off my 02 Envoy I later realized, from in the office, that my headlights were still on, minutes later. I knew they were set to auto and should have been off, so quickly went out to take a look, sure enough I could not manually turn off the lights with the in cabin switch.

Popped the hood and noticed my fuse box was smoking, removed the covers and found the 46-HDM relay was melting down on the fuse box. I quickly found a pair of pliers and disconnected the battery, but not before some damage was already done:

(I have a few surrounding fuses/relays pulled in this picture to, needed to clean them up from the left over melted plastic)

So my obvious concern is what caused the problem, could it be as simple as a bad relay? I wanted to ask for some advise here, as I do not want to replace the relay and have the same problem again in a day or so. Also, I am not sure if the entire fuse block should be replaced at this time, or if a cleanup job and ensuring the relays seat properly is good enough?

Any advise is appreciated.

 

[MAY03LT]

The only times that I've seen that were when aftermarket HDMs were used. Was the HDM an aftermarket one?

 

[d-wreck08]

Funny enough it was an AutoZone one, I had the issue of my headlights turnning off while driving down the road in the middle of the night, that has probably been 2 years ago now, but yeah it was replaced.

So I'm guessing pick one up from the dealer and go from there?

 

[The_Roadie]

The root cause could be a relay (it's solid state and fails, but rarely) that went bad internally, or a relay receptacle that got loose or oxidized and generated its own heat in the blade socket. I wouldn't just replace it without taking the plastic part off the fuse block and inspecting and cleaning up and tightening the blade receptacles very well. And shine up the relay blades with sandpaper before putting it in.

 

[d-wreck08]

Ok, so I attempted to get everything apart, and after getting the box's 2 main parts pulled apart, the 4 individual "harnesses" I would call them did not all want to come apart. 2 of them stayed in the bottom portion of the box, and were no issue, the one harness over the melted relay is stuck, as well as the one right next to it. I tried to pry this apart, though I have to admit I did not have much room to work with the wire restraining my work space. After a small amount of prying, the harness started to split in half, and I could see all the wires inside. I decided to stop here, as things seemed to be going south and yes I loosed all the bolts before prying, even removed the one directly above where the melted plastic was.

I'm thinking it may be time to take it somewhere to be looked at unless anyone has better advice on how everything should come apart, but it seems like things are melted together, and I am at a loss as of how to fix it without [SIZE=11pt]rewiring most of the box.[/SIZE]

[SIZE=11pt]Thanks for the advice![/SIZE]

 

[CollectorThis]

Mine looks exactly like this. Please keep posting updates.

 

[d-wreck08]

Update/Resolution:

Day 1:
Took this in to the dealer to have them diagnose it, despite the obvious physical damage to the fuse box, the CEL was on as well. This caused the dealer issues, as they could not give me a clear cut reason why the CEL light was on, as they kept getting errors on their diagnostic tool. After a few hours of them having it, they offered me a loaner car to drive until they had a better idea.

Day 2:
Dealer called back late afternoon and still could not tell me why the CEL was on. They told me they would have to replace the under the hood fuse block, along with the harnesses before they could move forward. They also indicated that they had a Buick Rainier in there a few months ago with the same issue, and replacing the fuse box fixed everything. I was happy to move forward with this fix, as my car still ran, and after opening the fuse box, thanks to Roadies advice, I knew I was going to be in over my head replacing it.

Day 3:
Late afternoon I was contacted and told replacing the fuse box fixed everything, and that the cause of the problem was a bad relay. I believe it was the 46-HDM as this was were most of the damage/melting was. This is what I had suspected, thanks to MAY03LT, but wanted a professionals take on it.. At the end of the day I spent $800 bucks but was happy with the service and peace of mind knowing it was fixed right with GM OE products. Oh and the 2014 Buick Verano with 300 miles on the odometer was fun to drive for 3 days

Other note:
As mentioned above I did replace this problem relay with an Autozone special a few years ago. Another reason for me to hate Autzone parts.

Thanks again for the advice everyone!

(Updated: fixed grammatical errors)

 

[The_Roadie]

Appreciate the report, even though it cost you a lot to deliver the news. It's normally a sign of the forum volunteer's failure when we hear of dealers being the troubleshooters of last resort.

 

[CollectorThis]

Little late but maybe I can save someone $800 bucks. The 2 larger harnesses are a little harder to get out than the 2 smaller ones. You need to take a skinny screwdriver and pry them out slowly while you continue to unscrew the bolts.