The Stovebolt Site Forums The Shop Area The Electrical Bay Some kind of relay between switch and heater?

Hello again my fellow stovebolters!

I'm rewiring my truck, and so far so good, but i dont really understand the heater wiring.

the wire goes from the switch through these wierd things:
Pic1
Pic2

The first one gets really hot when the heater is turned on after about 20 seconds. Also it says "Bat" at the side where the wire goes to the heater (isnt that the wrong side). And it doesnt seem to go through the second one at all... (See pictures)

So my guess is that the first one broke, and they didnt bother take it away, so they just left it there or something..


But what are they? Do they have any function? is it to 12V-to-6Volt something? can i take them away?

Raoul.

they don't have enough terminals to be relays.. they are either resistors or voltage regulators/converters. your '51 was originally 6v - has it been converted to 12v? if so and you are using 6v components, then that is what the devices are for... they throw half the power away in operation which is why they get hot.

if they are resistors, it doesn't matter which terminal is which..

Yep, ceramic covered resistors. One to drop from 12 to 6 volts and the other one is the fan speed control. And yes them critters get HOT!

Allright, thanks! Butt still though, it looks like the fan control isnt connected? My switch has two modes. Thats enough control right there

Are there modern resistors to get the voltage from 12 to 6 volt that arent getting that hot? I dont really like it

Raoul.

you'll have to learn to like it, generating heat is the only to "waste" excess voltage/current

Bill

Only one other solution, change the fan motor to a 12 volt motor. Then you only have 1 that gets hot the control.

Those both like controls to me. Originally you would have had some kind of off/on and speed control for your heater fan. To drop the voltage you need a 1 ohm resistor with a 50 watt rating. Here is an example: Resistor That part is designed to be attached to sheet metal to dissipate the heat. You can probably buy one from an electronics supply house. The truck part vendors sell them too.

Thanks i bought that resistor, but from ebay instead. I hope it dissipates the heat better. Also, the switch to the heater is:
-OFF
-HIGH
-LOW

And theres no heat conrol, but i guess thats because it gets its warmth from the radiator?

Thanks a lot guys!

You will want to fasten that resistor to clean metal. A good grease such as that used on the back of power transistors would help move the heat away. You can buy that at an electronics supply store. I think Antique Electronics Supply would have it. They have a very helpful site.