The Stovebolt Site Forums The Shop Area General Truck Talk Oh no not another heater question?

Hello all, I have looked through the search engine for help with these question but have not found much help. I find this new set up on the board a little harder to manouver than the old but anyway here are question. I have a GM Master heater in my 1950 1/2 ton 5 window pickup. I realize that these heater are aftermarket or dealer installed options. I believe that this heater is what is referred to as a recirculating heater. It does not have any fresh air circulation it just recirulates the air in the cab. It has three doors on the front and a pipe that can move air to the defroster. I do not have the hoses or one of the plastic boots that connect the defroster to the appropriate place. Is this an older type of heater that was placed in a 1950 or is this appropriate for the year? I see some discussion about recirulating heaters that take outside air and warm it to heat the cab. I do not have a camera to send a picture presently. I have seen some pictures of heaters and I Know itis not this type. The fan works fine but there is little heat off the core. I will remove the thermostat in the spring and see if it is working properly or even if there is one in there. I could not get much heat built up in the engine when I had it running before I put it away in the fall. Could there be any other reason to not get adequate heat out of the heater? I have had to leave a little choke on while the engine is running or it stalls out. If its because the engine has not been run much over the last quite a few years and it needs a carb job done on it or if its because it does not warn up to operati
ng temp is the question? Anyway I can put my mechanical skills on the head of a pin and I would appreciate any feedback I can get from the guru's or anyone who has had these experiences. This is a great place and I thank all who paricipate in giving their knowledge out to us novices. Many Thanks Dan V

A picture of the heater would be helpful but from your description it sounds like an aftermarket version. Have you checked the core to see if it is plugged? I also have to tell you that these heaters are nothing like their modern day counterparts they don't throw a huge amount of heat. I had a 49 1/2 ton that had a heater like you described I completely disassembled and cleaned it and it ran better. They are fairly easy to take apart usually just sheet metal screws and 2-3 bolts through the firewall. All the hose parts are available from the vendors like http://classicparts.com/ and http://www.truckandcarshop.com/

The heaters GM Canada used are nothing like the American ones. If it says GM on the front then it would have been dealer installed. Does it look like this?:

http://www.ironchief.com/gallery/view_photo.php?set_albumName=album03&id=DCP_2073

The core may be plugged. Hook a garden hose up to it for testing. Good luck.

Curt B.

Thanks. That isn't the one I have. I will have to get a camera and take a picture of it. Thanks for the help. Dan

I am trying to attach a picture of my heater. Hopefully this works.

Picture

By danv, shot with Canon PowerShot S100 at 2007-12-26

Sorry for posting the whole picture here. I thought I was sending a link. Somewhat technically challenged. Bear with me and I will figure it out. Dan V

You'rs is similar the heater in my 38. If your fan, thermostat & core are working OK it'll put out enough heat to run you out of the cab. If your truck isn't coming up to temp you have a thermostat problem. It's either stuck open or opening at too low of a temperature. Once you get a good thermostat in the truck, if the heater still doesn't put out enough heat, check the heater hoses. If the hoses don't get hot to the touch with the engine at full temp, the core is plugged, not allowing the hot coolent to circulate through the core.

i have one like the one in the picture in the 6100. mine has three horizontal doors and the defroster motor doesnt work. im missing drivers door glass and the heater wailed today when i went for a ride to check a repair. outside temp 32* engine never came up to 180 but then i have a new rad core.

On those little heaters like that one,dont you just shut the 3 doors and it forces the air up to the defrosters? Or am i thinkin of something else?

On that type of heater there was a separate defroster unit offered as an option and it had its own motor.

Dan,
I have the recirculating heater and it is the Canadian version. I found out when I replaced the core that the Canadian version has five rows and the US version has three. I had to have mine modified to use the US style core.

Your truck should heat up to operating temperature in the summer, without a thermostat. That is how I started with mine, to make sure there were no overheating problems. Also from what you describe, it sounds like your engine may be starving a bit, possibly due to a carburetor problem.

My truck was commercial blue then I got it but that was pretty hard to tell because of the rust. You can see it in the gallery.

Curt, You truck is immaculate.

Thanks for all the feedback guys. The heater has a boot that comes out the top of the heater where hoses must be attached to feed the left and right defrost boots on the front windshield. There does not seem to be any controls to move the heat up or down only the fact that you can close the three doors in the front. The heater is open at the bottom and when the doors are closed the heat must escape up the defrost or down to the floor. There is a switch that controls a two speed fan at the back of the core. I will have to figure out why there is no heat out the core but suspect that there is a stuck thermostat or none installed. The engine did not seem to heat much and the heat temperature was not raising when I had it out. Maybe the guage is not working. It has the battery out now and I will have to follow up in the spring when I fire it back up.

WOW, Dan. Thats one sweet lookin pickup.
If you ever want to sell that grille guard,i'd love to have it for my suburban.