Skip to content

GMC Engine Block Heater

Have you ever tried to find the plugin for you GMC Sierra’s engine block heater? If so, I’m sure you were as frustrated as me when I went looking for mine!

The designers at GM must have thought it was a great idea to put the plugin where they did. Seems to make sense in some ways. It’s relatively easy to get to, as long as you know where to look.

Where you ask? Well, on my 2001, the plugin is located in the front driver’s side wheel well near the front, behind the tire. It’s probably easier to get to it if you turn your wheels to the left first. On the 2001 there is a plastic piece that is between the wheel and the engine. Down near the frame you should be able to see the cord of the block heater. It might be coiled up or it might be sandwiched like a letter S over and over (there is Christmas candy that looks like this, like a ribbon).

Now my only problem is trying to figure out where to feed that cable out through. Once I detach the cord, it’s going to drag so it can’t stay in the wheel well. Guess I’ll have to fish it up through the engine compartment and out through the grill or something like that.

When I figure out the easiest way, I’ll add more to this entry. ;)

Please feel free to add comments about other models and where you can find their plugins.

Update: I finally got around to pulling the plugin through to the front of the truck. There are a couple ways to bring it through, but the hardest part is getting the plug from the bottom of the engine block up into the engine compartment! A rope or old coat hanger would probably have helped but I have long arms and managed to fish it through. ;)

One thing you can do is have it come out underneath the grill. There’s a gap in between the bottom of the grill and the top of the bumper that is large enough to fit the plug through. You’ll probably have to take the plug cover off to do it because it kept getting caught.

The other option (if you have front tow hooks like me) is to pull the plug through and attach it to the tow hook on the driver’s side. It’s probably easier to do that since you don’t really need to fish the plug up through the engine to get to the grill. Of course, it’s a lot lower down so it’s sort of personal preference where you’d like to plug into. ;)

Update 2: Well, I now have a 2004 Sierra and it turns out the block heater cord is in the same spot. It was a little more difficult to get at this time though as it appears the plastic wheel-well insert is larger and stiffer than on the 2001.

23 thoughts on “GMC Engine Block Heater”

  1. jivany. Not many times I’d bother posting a thank you on the web but you deserve one for this tip on where GM hid the block heater cords on these new Sierra’s. Dad lent me his truck this week (after my car was broken into – but that is another story) and I’m trying to find the plug for the block heater last night at around midnight. -30 outside and I’m head under the hood and then under the truck with a trouble light trying to find the blasted cord and no luck. So I give up – figure I can groan a start of the thing if I have to. So I’m downloading my email later and I figure – take a chance on google with a search – maybe find someone who figured it out. Sure enough I find your page in like two minutes. Thanks for showing me the way. Went back out, found the cord in a second, and plugged it in. The Sierra roared to life this morning. Thanks and all the best, Andrew

  2. Boy…Andrew and I must have been in the same place…just the other side of the street…He said it exactly the way I would have and was experiencing this frustrating situation…two seconds after finding your web page…I went out side and sure enough there it was “well hidden” in the front lower part of the drivers wheel W. THANKS SO MUCH FROM 30 BELOW IN NORTH DAKOTA….had to freeze out there looking and looking before I thought of going on the web and finding your message….thanks again…Lonnie (2003 GMC Sierra)

  3. jivany

    Do I ever appreciate the postion on the net. It would have proved very usefull if my dad hadn’t run over the cord probanly a year or more ago. He always parks the truck in the garage and never noticed. Now I am spending the night at my girlfriends and it is -51 degrees celcious outside. It took me 2 hours outside in the dark with the worst flashlight in the world to figure out that it had been ripped off. Even after reading this posting.

    Thanks anyway.


  4. I need some help….

    Took my truck to dealership for the 5th time to replace the block heater.

    They just called me to say that it meets spec and is not to start till ambient temp is 0 degrees!!!!

    I told them it has ALWAYS worked at any temp when I plug it in till it quits like it has the past 4x!! I also told them that I recall owners manual says something about plugging it in at 45 degrees….

    I am going to seek a legal rememdy but would love to find a “block heater expert” to help me prove this lie….

  5. @Sharron: You may not have a block heater. It’s an option on the Monte Carlo SS. There should be a sticker in your glove box that lists all of the option codes for your car. Look for code K05 on the sticker. If that isn’t found, you probably don’t have the block heater.

  6. ok I wil check on it if I don’t then I guess I will be using their road side assistance everytime it gets this cold out. If it does have one do you know where the cord would be stored?

  7. @Sharron: I’m not sure but the cord might be coiled up in the wheel well like on the trucks I had (see the post). I think the SS has the same 5.3L V8 as the trucks. If it’s not there it’s probably tucked away somewhere in the engine bay. Look around the edges of where the hood comes down. One of our cars was like that. Good Luck!

  8. 2009 GMC 2500HD 6L

    Found it…. In front of driver side front wheel. Has a bright orange cap on it. Saw the cap a hundred times thinking it was some kind of cover for a grease fitting or something. It’s hanging low, right out in the open, you only need to know what you’re looking at.

    Won’t go past tow hook cover. Got it through cover in middle of bumper. Lift cover off bolt, pull plug through and replace cover over bolt. Hope it stays there if not, cord might be long enough to let plug go under front wheel,,,,, probably have the opportunity to re wire it after that….

    Good Luck and thank heavens for this web site, it started me looking in the right place.


  9. I drive a 2009 sierra ext cab 4.8 1500.. Just wondering if I have a block heater or not! I’ve looked but can’t find anything..

    1. Good question about the 2009 Sierra. I don’t think the block heater is standard equipment anymore. It might depend on the trim level. Recently I was using the GMC online configuration tool and it had “block heater” as an optional item.

  10. The block heater cord on a 2009 Sierra is located next to the aux battery on the passenger side in the engine compartment. It is coiled and ziptied.

  11. I have the GMC Sierra SLE 1500 5.3l 2008 model GFX All Terrain Custon Cab pickup.Does this model have a Block Heater?If so, where is the plug located?Much appreciated.Thanks


    1. It might not. It seems GM started removing block heaters as standard equipment sometime in the last 5-7 years. Only on the upper level trims would you find them included unless it was ordered with the option. That said, check in the wheel wells to see if the cord is tucked up under the inner plastic piece behind the wheel. You might need to turn the wheels full left or right to make it easier.

    1. I assume the 305 has a block heater (it at least has the option of one as you can find the part pretty quick online). Check in the front wheel wells for the cord.

  12. Anyone know where the chord is on a 2012 sierra ,the manual said its attached to the fuse compartment but I can’t find it

Leave a Reply