GMCStepSide

You need to either modify the thermostat on the cord so it is on constant or reroute the cord so it goes out one of the tow hook holes in the lower air dam. Make sure the thermostat is outside of the body so the cold minus zero air can get to it. I played around with mine a couple years ago and found that thermo to be very sensitive to the warm radiator as the plug was sitting just under it. I feel your frustration - don't you just love the television commercials on KTUU and KTVA saying "It's below 20 degrees, remember to plug in." It makes for a real false sense of comfort do so for those who own newer GM products but most folks don't even have a clue. I contacted KTUU and the Muni about it a year or two ago as the block heater program is part of their "keep the air clean by plugging in" program but they didn't care enough to contact me for the full story...oh well.

Welcome to the club Alaska 06! That's why the 06 Silverado gets parked in the garage at night and the 04 Malibu Maxx stays outside - I can plug the Maxx in at any temp and the block heater will work. The 06 with the tumor plug is a joke. You are right about starting a cold Cessna at 5 degrees but GM and the EPA must believe it's no big deal for our trucks. I too have an 06 Silverado, left it out for one night two nights ago and when I went out to start it up thought I was going to have heart failure as the truck sounded like it hadn't been plugged in at all. Granted, it only got down to 2 degrees that night so the block heater never even got a chance to do it's job. I've got it in the garage this morning and will be removing the tumor plug shortly after the Super Bowl or during if it becomes a blow out. You might check to ensure the other end of the cord is actually attached to the block heater...they may have forgotten to do it. P.S. I had another 06 with the tumor plug, cut it off and other than a very rare CEL, everything was fine - and the truck ran much better on 2 degree or 15 degree mornings! Take that GM and EPA!

Yes, it's a round black cap that is located on the plug in end of the block heater cord. When you go to plug it into an extension cord, you'll see it has a black cap on the top of the plug. That is the thermostat - assuming you have a 2006 model year and beyond. Your sig shows a 2003 1500...if you have a 2003, you don't have ther thermostat plug. Yours will operate any any temp...

I'm telling ya, cut that tumor plug off and let the CEL do it's job. Every now and then I get a CEL light but with enough start/stop cycles, it would go out unless we were having a long stretch of 5 or 10 degree weather. When I asked one of the GM Service Managers about the CEL light, he checked and said doing so will not hurt the engine, tranny, or anything...it will just be a minor annoyance for the driver. Heck, that's what they make black electrical tape for - to cover that minor annoyance. Plus, I'm protecting my engine versus cold startups at 5 degrees day in and day out.

Still no problems with mine and I've plugged it in at -25 as well as 15 degrees and never a problem. As you know, I cut the plug off and replaced it....everything still works fantastic.

Currently -21 degrees outside at 6:30 p.m. When I got up this morning it was -24 and we never saw it go above -8. I had it plugged in ALL NIGHT LONG and never got a code, light or even a whimper. I started it this morning and everything performed as normal. Granted, I'm on the other end of the spectrum in that the thermo plug is supposed to pass electricity to the block heater when it's below zero thus it should be functioning as GM intended at this point. However, the real test will be when it's 10 degrees out and I use the timer for four hours. I was doing this before the cold snap hit, and had it working between 5 degree nights and 20 degree nights, and never had a problem. No problem since I cut it off - at all. And my service manager told me on Monday that he's been recommending it to those who will use a timer. However, he said he was waiting for the first truck to come in with a fella who cut it off and left it plugged in overnight at 30 degrees. At these temps, it will be a while before he sees him.....

Yeah, follow the plug up as it goes by the fuse box...there is where I cut is so that I had plenty of tail under the hood to resplice if there was an issue. It worked for me and I'm a happy camper again. Go for it!

Not a problem in the world. Everything seems to be functioning as usual except I can hear that block heater run when I plug it in...however, I'm running the timer so the only time I hear it is when I go out to start it in the morning. And I've been using the block heater nightly - with the timer - since I cut the thermo plug off and replaced it. Would I do this again - you bet as it hasn't seemed to affect anything. I've gone through roughly 15 start/shut down cycles and no light, nothing. And the temp gauge has worked consistently. By the way, I did get a message back from the Municipality of Anchorage I/M Program Administrator...it read - Thank you for sharing this information. I will have our office research this issue and we will pass our findings on to all of our I/M licensed mechanics and facilities. Who knows, perhaps the Muni will be recommended everyone in Anchorage driving an 05 or new GM truck cut the plug off and use a timer....we'll see. But it worked fine for me!

No sweat...I cut the plug off so it had a 12" tail on it thus I'll be able to replace it should I end up with the dreaded code. I figured rather than complaining about it, I'd work on a solution. We'll see if it works. Heck, if that's the only issue I ever have with this truck, I've got it made.

Well, GM-Tech, I took your advice and late last night decided to cut the d**n factory plug off and install a quality grounded plug. At 2 degrees, the fingers got a little cold but I was able to get it accomplished in a few minutes. When I got up this morning, the truck started like it was 75 degrees outside (the temp was actually -9 degrees). I had it plugged into my timer so that it was only on for 4 hours. The truck started up nicely and you could see on the windshield where the warm air had convected out the defrost vents onto the winshield. I drove it 90 miles, ran a bunch of errands and was back home with no problems at all. No codes or lights, and the temp guage worked fine the whole time. IMHO, if you live in cold climates where it gets below 20 degrees on a regular basis, you need to cut the plug and replace it with a quality grounded plug. Then be sure to use a timer to help it get warm, plus the timer will help save on the electricity bill.

On the way home I stopped at the dealership and was informed by the Service Manager that they were still attempting to get information about the block heater "thermostat". He said they had called the Fairbanks dealership and they were just as baffled as they hadn't heard of it. I gave him this scenario. If I was living in Fairbanks, and it was -5 degrees outside, and I had the truck plugged in for four days, wouldn't it throw a code. He apologized as he said he couldn't answer it because he still didn't understand why there was a thermostat on it and the entire code issue. I asked him about the wear and tear on an engine being started at 5 degrees above without being plugged in (or the screwey thermostat not letting it come on until it was below zero) and he stated there was significantly more wear and tear on an engine when if it wasn't plugged in. I then asked if GM was going to warranty the engines for those of us living in colder climate (I already knew the answer) and he simply stated he was waiting to hear back from GM. It's supposed to be -5 here tonight so you can bet I'll be out there freezing my a## off making sure that thing has kick on. I'm going to plug it in all night long and pour the AC to it...try to get a code tomorrow...assuming the darn thing actually kicks on tonight.

You forget, we all move down there to whatever hot spot you're living in and there's no one up here to keep the oil flowing. Once that happens, you'll see $8 a gallon gas, then you'll be begging us to move back up north. As for shivering in my boots, no, I just want my fellow taxpaying citizens to know about this so they can make an informed decision before purchasing a GM truck. In the wintertime, the air used to get an unhealthful to breath rating that led to EPA fines that were paid by the taxpayers. Most of us don't want to have to fund those fines and I might have thought twice before picking up a truck with a block heater that is inoperable above zero degrees. Would have looked harder for a good used 2003 - 2004 model. As for GM, they've got their own problems and mine may be minor but at least folks should know about this so they can make an informed decision before purchasing. Who knows, the next thing the Municipality of Anchorage will do is implement a tax on those of us with this screwed up plug as we're "big polluters".

I went to my local GMC dealer today and he looked at me in dismay as I explained it to him. He didn't believe me until he brought it up on techline...then he was speechless. He called all his mechanics over - and I mean he stopped all the work to get them over there - and none of them had heard such a thing. They proceeded to run three extension cords to four new 2006 trucks that were by the building. They plugged them in and to their shock and amazement, found the block heaters didn't kick on. I re-explained everything to them and they finally brought in their mechanic who deals with electrical issues. He too hadn't heard about it but proceeded to do some checks and found that the block heater wasn't on. One of the mechanics even replied that the trucks - they were all frosted up at 1:00 p.m. still - were colder than hell and he felt even with a thermostat that the block heater should have kicked on. Short story is I left the whole damned group of mechanics, service writers, service manager and the general manager in total awe that GM could be so incredibly stupid. They said they would "look into it" and call me tomorrow. In the meantime, I'm contacting Channel 2 News to have them do an investigation as this is doing nothing to help us keep the winter air clean and avoid EPA fines. We'll see... They did warn me against cutting off the plug until they were able to fully understand GM's reasoning. Nice, tonight it's supposed to be 0 to 10 degrees for a low, and I paid for a block heater that'll be sleeping through the cold night. I've always owned and supported GM/Chevy trucks but this one deserves a big GM SUCKS!

I love it. In Anchorage, we have a program were you are asked to plug your vehicle in when the outside temp drops below 20 degrees. This helps the city meet EPA standards as a cold engine warming up pollutes more than an engine that has been plugged in for a few hours. HOWEVER, thanks to the damned idiots at GM, that isn't the case for us GMC and Chevy truck owners. I see alot of mornings at 5 to 10 degrees...for years I have always plugged my trucks in when it dipped below 20 as it prolonged the life of the engine. I always used a timer so that it came on at 2:00 a.m. so it was warm when I headed out at 5:30 a.m. I wondered why my 05 GMC wasn't making any sounds when I would plug it in...unlike my previous GM pickups. Now I know it was some damned fool sitting at a desk with a slide rule making decisions for us in the frozen north. It's Alaska fellas...I grew up here...it gets cold - who knew when we bought it from the Russians!