The Stovebolt Site Forums The Shop Area The Electrical Bay 1951 heater wiring

I have wiring diagram books and tech manual for my 1951 / 3100 Chevy truck but none have a wiring diagram for the heater. I have the switch under the dash and wires coming out of the blower motor with no idea what colors go where. Thank you!

Bil if this is a 6 volt system, its pretty easy. There are two wires on the heater, one of which is short and has a round terminal on it for grounding it to the heater case. The other simply goes to the switch. Then, the other terminal labeled BAT on the switch goes to your power source, usually the Ignition Switch on.

If its converted to 12 volts, there is a stepdown reducer in the mix. Then its wired in this order... Ignition Switch (positive) to the Reducer, Reducer to Switch, Switch to Fan Motor. Again, the negative side is grounded to the case. I spent a lot of time on this article that may help...

http://devestechnet.com/Home/Native12VUpgrade#heatersystem

DAD550, Was the temperature control valve used on the 1950 3100? IF so, is it the same as the 1951? And do you know the make and model?

Thanks,
Deron

From what I have read on this forum heaters were installed later by dealer or shop.

I guess it would depend on what type of heater was installed in your truck

Mine is a Harrison fresh air heater and there was a ranco valve installed on the firewall.

I don't know if other brands or type used the valve.

If you post the type of heater you have maybe someone will be able to give you a better answer

What's the temp rating on the thermometer you all are using with your heaters? Is this a standard thermometer used in a 216 as is used on most Chevy engines or is it something special?

Thermometer? The Ranco Valves are the same up through at least 1953 and found on only the Harrison fresh air style heater. Are you talking about that or the engine Thermostat? I run a 180 degree thermostat, but I hear they also put 160's in some.

What they called "160 degree" thermostats in 1950/51 (the stock/standard thermostat on small trucks), started opening at around 160 degrees, and were fully open at around 180 degrees.

Doh! Yes I meant thermostat. Is there a special one for the 216 or are they the same thing I'm familiar with for a SBC?

Markiemark9,

The SBC thermostat fits perfectly in a 216. I recommend a "fail safe" thermostat. These thermostats "pop open" when they fail or get stuck, thus reducing the chance for a over heating situation.

Tim

Thanks!

The Air-Flow heater was an R.P.O. In 1947 after that year it dropped to the accessories list for dealer or owner installation.
https://www.flickr.com/photos/advance-design_parts_co/17056970488/in/album-72157651718017649/
1947-early 48 leftovers, more in GMC than Chevys it seems? Two versions, deluxe had the defroster attachment as shown. This heater appears in the Salesman Data Book in 1947.
https://www.flickr.com/photos/advance-design_parts_co/9201965046/in/album-72157631868452754/
Two most common installs 47-52 (53-55 1st Series have internal door)
https://www.flickr.com/photos/advance-design_parts_co/8129448404/in/album-72157631868452754/
https://www.flickr.com/photos/advance-design_parts_co/8129470099/in/album-72157631868452754/

I am restoring a 47 and a 53 now. I wish they wouldn't have cheaped out on the 53 and decided on a simple Decal as opposed to the earlier badging. I do like the fresh air aspect of the 53 one. Harder to find cores for the 53 too. Thanks for the pics Brad. I always know where to go to get information on this stuff!

Dads50,

Thanks. I have a Harrison also. Someone removed the valve and mounted the battery in that area. Do you know where I can find information, instructions, or pictures of the valve installation?

Tim,

Thanks. I picked up a copy of the 1950 accessory installation manual.