The Stovebolt Site Forums The Shop Area The Electrical Bay Heater blower switch...smokin'!

'59 with stock setup.

Just wired in the heater blower switch. When I turn it to one of the ON positions the coiled wire on the back side of the switch heats up and glows to varying degrees depending on which of the detents the switch is at. And smokes! But nothing out of the blower motor.

I'm hoping that the smoke is just a new switch cleaning itself off, burning off whatever got on it before this initial use. Yes?

But why is there even a coil back there? Why isn't it just a simple on/of switch? And if this doesn't activate the blower motor, what does? Or is this a sign of a dead motor?

Help?!

does the fan motor turn in any switch position?
a new switch resistor will always smoke some .... the "coil" on it is the dropping resistor, should be a 2 or 3 position switch to control fan speed

Bill

Read this POST

But why is there even a coil back there?
If your switch has three fan speed positions.
High, Medium, Low: It would have two taps on the coil.
If your switch has two fan speed positions.
High, Low: It would have one tap on the coil.
The High fan speed position sends full voltage to the fan motor and bypasses the coil.
The coil is really a resistor.
How electricity works. Ohm's Law clearly explained. The Ohm guy is the resistor.

Why isn't it just a simple on/of switch?
To be able to slow the fan motor down.

And if this doesn't activate the blower motor, what does?
It should activate the blower motor.

Or is this a sign of a dead motor?
Could be a bad motor.
Send battery voltage directly to the blower motor. (Bypass switch)
If motor does not spin.
Hit the blower motor housing with you hand.
If it starts to spin do the below.
Take the blower motor a part and check brushes if OK, sand commutator bar with emery cloth.

OK, got it. I'll go back to it tomorrow and start by going from power directly to the motor. Which is to say that the switch has no effect on the motor. (3 position switch)
I like "hit it with your hand." Oh that all problems were that easy to fix.

I'll report back.
thanks for the guidance, gentlemen!

OK, got it. I'll go back to it tomorrow and start by going from power directly to the motor. Which is to say that the switch has no effect on the motor. (3 position switch)
The motor is powered by the switch.
The reason to send power directly to the motor, is to diagnose if the problem is in the motor.
Or if the problem is in the switch.

Just remember with a 3 position switch there are 2 blower motor speed options.
Position 1 = OFF
Position 2 = Low speed
Position 3 = High speed
The above Speed Positions are for the Deluxe Heater switch.
On the Recirculating Heater switch Speed Positions 2 & 3 may be reversed

1959 Chevrolet Truck Shop Manual - Supplement
Deluxe Heater Controls Fan Lever

Looks like the 1959 Chevrolet truck had two types of heaters.
Deluxe Heater used this Switch part # 3144263
Recirculating Heater used this Switch part # 3757698
Both are 3 position 2 speed switches.

Which switch do you have?

If you don't care about a low speed setting and just
want the fan to blow, put a toggle switch under the dash.

GREAT write up jorb!! Another thing on those coils (resistors) you mention on the back of the switch, they should have a ceramic/silica coating on them. If not you can recoat them with Autocrete Hi-Temp Ceramic adhesive or find a NOS switch.

Tim

I by-passed the switch and got nothing so I pulled the motor. Uhm...this could be the problem.

The shaft will only turn if I put vise grip pliers on it. The motor is a sealed unit so the best I could do was spray lubricant down the shaft and that made no significant difference.

The amazing thing: NAPA says they can have a replacement motor at my local store by 12:30 this afternoon. Go figure.

Fixit...what does that coating look like? That is, how do I know if it's on my aftermarket switch or not? And if not, where can I get some of that coating you mention?

PathwayRev,

I got the coating direct from Autocrete on the internet. It is a bit pricey, but it works! You mix it with water until you get a slight paste. May need two to three coats.

Tim

The coating is not required for the switch to function. It is there to prevent the ole lady's billowy shirt from catching afire.