I have picked up this working used OEM Delco-Remy "AIR" switch that is used with a Harrison fresh air heater. Note the ceramic/clay "resistor" (correct name?) on the backside and the condition that it is in. Is this a concern when the switch is in use? If so, is there a way to remedy this situation?
I think that as long as the wires are intact it should work as designed, to dissipate heat. It does look a little crusty, as some of the ceramic material has chipped off. Maybe wire it up on the bench and test it.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Be aware that the coil will get VERY hot during use as it controls the fan speed. DO NOT TOUCH! I learned that the hard way! That's why later designs of blower speed control resistors are mounted inside the air box in front of the fan output. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Yep burned my fingers on that as well .mine is not as bad as yours but I thought of trying an epoxy type glue but never looked into it .It would have to be a high heat coating ,or possibly a heat shield so one would not touch under the dash with your fingers and also protect from igniting something on fire.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Add a small tube from the heater outlet and point it towards the switch to keep it cool. It only gets hot on the lower speed settings. The ceramic absorbs the heat, thats what it needs on it, not epoxy.
Thank you Jerry. The answer was sitting in my shop. I heat with a wood stove, and also have a maple syrup sap boiler in this space. Refractory cement is a staple to perform routine maintenance on both fireboxes. Mission accomplished.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
That is a resistor. In college I worked at Dale electronics in Nebraska where we made those all the way from crinkled flat wire on a 3 ft ceramic tube for French subway cars to thinner than hair size wire on a fiber rope soaked in a varnish, clipped and terminated for various ohms for Chrysler corp. For what you have we baked on a high heat paint for insulation and if it was a variable resister like you have would remove a slot of the paint to be able to make contact for a sliding contact along that slot resulting in varying voltage to the motor therefore varying the speed. Having the coating flaking off shouldn’t affect the workings but just potential contact with something it shouldn’t touch. Sparks/smoke not Good. Several coats of bbq grill paint with everything taped properly including the strip where the slider hits should do you. If you want more protection, the refractory cement may work as long as you’re not in too humid of a climate for it to absorb moisture. I would probably paint it first. Make sure that you keep that contact strip nice and clear of anything.
Larry Old man᠁Old truck᠁neither one goes very fast. All you need in life is TIME, PATIENCE and MONEY. If you are missing one component, you'll need an abundance of the others two.
I don't believe that resistor is a variable type, just an alternate load for the motor. There's likely a potentiometer (variable resistor) inside the switch, although I have never taken one apart. So the slider would be inside, not on the external resistor.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
You could certainly be right about it not being a “variable” but rather a simple 2 speed switch, otherwise I can’t imagine a reason to reduce voltage on a motor then through a variable resistor as well.
Larry Old man᠁Old truck᠁neither one goes very fast. All you need in life is TIME, PATIENCE and MONEY. If you are missing one component, you'll need an abundance of the others two.
