MS3DALE

Just wanted to let you guys know that I ordered and received another cord,I gave it to a buddy of mine yesterday who is an electrical engineer to see if a new "non-thermostat" plug end could be put on. I'll let you guys know what happens.

Heres what the tag on the end of my cord reads... 10 AMP 125 V 1250 W

I think 1250 watts,But again I can't get a "concrete" answer,But I'm still checking. On another note,after beasley posted that article from the Dec. 04 Techlink I remember getting that issue here and reading it but not thinking much of it since I didn't think my '04 was affected,Guess I was wrong! I kinda' forgot about that article,The answer we were all looking for was right under my nose all along since I keep all the issues of Techlink right in my desk here at work!

Arctic...Funny you should ask about part numbers,They changed heater & cord part numbers in the mid-'05 model year,The first design is a 3-pin brass colored connector and the second design is a 2-pin silver colored connector,Now the connector they are talking about is where the cord plugs into the heater itself. I have the first design since mine is an '04,'05's can have either.And of course '06's have the second design. To be honest with you I'm still trying to figure out if mines working above 0 degrees F,And still trying to find an answer why GM put a thermostat in the cords.

Yep,I know exactly what you mean. I might even call back just to see what another guy says. Sometimes though I think I know more than they do,(No...sometimes I know I know more than they do ) You probably feel the same way,I know our techs here do.

Allright guys heres the latest I came up with,This maybe a little confusing and long so bare with me I checked the service manual and heres the first thing it says about the heater not working: "Important,The power cord will read open if the ambient temperature is above -1 degree F (-18 C)" That would confirm what we thought all along,That it won't work above 0 F. Then I called GM-Partech and explained to the agent what we are dealing with and ask him if he could confirm a "thermostat" in the plug or when it should and shouldn't work,Well he told me no thermostat exists and it should work as soon as you plug it in and continue working for as long as its plugged in. Great I thought,Now I'm more confused So I did some tests over the last few days here since its been in the single digits but above 0 degrees. The first night (about 8 degrees F) I didn't plug my truck in and it had frost all up and down the windshield the next morning and when I started it up it took almost 15 minutes to get heat. The next night (same temp.,about 8 F) I did plug my truck in and the next morning the windshield had no frost on the lower half and when I started the truck it only took a couple of minutes to get luke-warm heat and about five minutes to get almost full heat. I know I said in an earlier post that it wasn't working before but to be honest I never really checked it that good, (Because I don't drive my truck everyday,heck it hasn't moved in a few weeks!) What I was mainly basing it off of was the fact that in all my other trucks I could actually hear the heater working,Kinda like a slight "humm" is what I always heard on my other trucks when the heater was plugged in. So now I'm really confused,I'm not hearing any kinda "humm" to verify it was working but I can't see how it wasn't working the night I had it plugged in since I had heat pretty quick and no frost on the lower part of the windshield. The only other thing I think I'm going to do is unplug the cord from the heater and test it,If that can be done. What do you guys think?

Didn't have a chance to call GM yesterday and won't be able to now until Monday. Arctic you said in your earlier post something about how someone told you GM put the thermostat on there because they don't want the block heater maintaining a constant 180 F for fear of possibly damaging something internally? Did he say what? I can't figure it out,It's baffling me ......I mean the engine runs a helluva lot hotter than that going down the road! Why would it hurt to keep the block warm when its 20 to 30 degrees F. GM-Tech,Do you have any thoughts on that?

Guys give me a day or two,When I get a free minute (Been out all morning plowing the lot here at the dealership!) I'm going to call GM-Partech on this and see if they can tell me something (I'm not holding my breath though!) Arctic,Your right it wasn't always like this,As I said in an earlier post before all my other trucks worked no matter what the temp.

OK,Just to update you,I plugged my '04 in last night for the first time ever since I had it (It never really got cold-cold here last year so I never tried to used it) And lo-and-behold it DIDN'T work,It got down to the upper single digits/low teens but not below 0. I know all my previous trucks (Which included a '94 S10 ZR2,'94 & '97 K1500 "OBS" trucks and a '99 K1500 "NBS" truck) worked no matter if it was below 0 degrees or not,so they must have put some kind of thermostat in the plug over the last couple of years I know I'll be switching out the plug end like everyone else has done!

You'll lose about 3 gallons if you drain it from the radiator,If you just remove the plug and let it drain from there (Or shall I say "shower" you. Be prepared if you drain it this way,it goes everywhere!) You lose a little over 2 gallons. I always use distilled water for mixing with the Dex-Cool. I really never noticed the thermostat or "tumor" thats on the end of the plug that everyone has been talking about,I do know this though,I've plugged mine in many times when the temp. is above 0 degrees,but below 30,and it works.

Nope,Its not a regular type freeze plug,It is threaded and actually screws in and out of the block. The picture you have there is same one I have here at the dealership and is a "generic" picture so-to-speak. Your heater will have threads on it.

The one you remove is on the drivers side rear,above the oil filter,Its a brass 17mm hex-plug. (So you'll need a 17mm hex socket,plus a 24mm regular socket to install the heater) Nope,You do not need to remove anything else.They don't even tell you to remove the driveshaft in the instructions,but man does it make it easier to install! Let me know how it goes

One other note that I forgot to mention that the instructions don't tell you,If your truck is a 4x4,To make it easier to install the heater remove the front driveshaft from the front yoke,You don't need to completly remove it,just the front half from the yoke.(It takes an 11mm wrench to remove the bolts)When you do just push the driveshaft back towards the transfer case and lower it outta' the way,You might already know this but just in case,Be sure not to turn the driveshaft once removed from the yoke.(You want to install it back the same way for balance reasons) If you have any other questions let me,I've installed a few of these over the years and have it down to about a 1/2 hour-45 min. job!

It will work for you,However part number 12497459 has been changed to a new part number,17800530. Either one will work. (You won't need the gasket,The reason you need it for the 6.0's is because you must remove the engine oil cooler line from the block which the 4.8/5.3's don't have)