Guys,
I'm trying to get some heat in my old '53 gmc. I have an old heater core, control valve, and fan and core shell that came in boxes along with the truck. I have the shell/fan motor/heater core installed on the firewall now, but have some questions:

1. How do I know if I have a 12 volt or 6 volt fan motor?
2. What does the part that controls the heat/defrost flapper look like? It appears to be a throttle cable like device like the choke control. Where could I get one or can I just get one at autozone?

3. How does the water flow control work? It has an element sticking off of it that looks to be thermostatically controlled. WHere does that thermo thingy mount and how does the little control on it work?

4. If anyone has a pic of their setup they could snap real quick and easy that would be super helpful. I haven't found anything on the internet. I did find one "switch" that clipped onto the dash edge but I believe it to be for the fan. What about the amount of heat? Is it controlled by the amount of water being let through the control valve into the heater core? Where is its control mounted?

Sorry for all the questions, I just like to supply as much info as possible so whoever reads this stuff can understand my problem. BTW, I believe it to be a factory original heater.

Last of all, would I be better off just getting the aftermarket heater setup like from classicparts.com and putting it in as far as getting by cheaper? I like the factory setup better and want to keep it if it is feasible.
Thanks,
JBJennings

Here is and excellent article on restoring one http://www.speedprint.com/deves50/heaterrestore.php. You are correct on the pull cable/knob it attaches next to the fan switch you have under the left side of the dash. Best explanation on set-up is in the Accessory Installation manuals they show that in detail I am sure Tim will see this and he can add those Links. Here are a couple pictures to help show the set-up as well. After reading your post closer I will add that I think the factory heaters add a ton of character to the truck and once rebuilt they are a nice addition. If your motor is original 6-volt it will probably just have one hot lead coming out of it most of the 12-volt replacements have 2-leads one + one -. Your heater would have cost the owner around $55 bucks back then which was a substantial outlay at that time. I say restore it and enjoy it!

http://good-times.webshots.com/photo/2738738300102454676GDFfat
http://good-times.webshots.com/photo/2282825960102454676njXUMq

Here is the 1951 Chevrolet Accessory Installation Manual instructions for a heater that should be a lot like yours.

Thanks go to Keith Hardy for kindly building and maintaining the website that provides this manual.

Tim

If you have a 6 v motor, it should turn pretty well when powered by 6 v. If you power a 6 v fan motyor with 12 v, it should be obvious that it is a 6 v.

Thanks a heap for that fellows!!!! That's exactly what I needed. I'll add some pics to my '53 on the Gallery so you guys can see the "new" interior when I'm finished. I've put new carpet and seat covers, headliner, painted the dash to match the body color, and am working on getting my heater and steering column cover installed and am going to drive it that way for a while. If I ever get the suspension to a point that I'm satisfied I hope to install air conditioning. But I'm going to get it driving like I want to before I ever consider the cost of a/c.
I did put an Eckler's transmission crossmember in and it dropped my turbo 400 down perfectly. It has no vibration now AND seems to have fixed my tranny shifting problems so that it shifts really nicely now. I'm turning about 2500 rpm's at 55 mph now and I believe I can live with that. The crossmember was $75 including shipping, and was well worth it to me, since I didn't want to take the time to fabricate my own.
thanks again,
JBJ