heater fan lost power.

Reply #45 – February 08, 2014, 09:15:35 AM

At any rate I'm tire of getting emails about this thread, unsubscribing.

heater fan lost power.

Reply #46 – February 09, 2014, 04:12:47 PM

I know my communication skills suck. But let me try one more time.

1. The circuit with the blower switch on High:
Fuse--function swt.--motor--blower swt.--ground.
Current draw =12 amps with a good motor.

2. The circuit with the blower switch on Medium:
Fuse--function swt.--motor-- blower swt.--resistor--thermal limiter--ground.
Current draw= 6 amps with a good motor.

Since putting the resistor in the circuit makes the current drop by half, means the total circuit resistance (motor+resistor) doubled.
This means the medium speed resistor has the same resistance as a good motor.

This means with the blower switch in medium, the maximum current draw you can have with a bad motor is 12 amps.
12 amps is less than the 15 amp max current rating of the thermal limiter.
With the extra current through the resistor and less air flow the resister overheats and trips the thermal limiter.

Thermal limiter, thermal interrupter, thermal fuse all different names for the same thing. They come in different sizes and shapes and
different designs. Their function is to break the circuit if the ambient temperature of the environment they are in exceeds their temp rating.

heater fan lost power.

Reply #47 – February 10, 2014, 10:39:25 PM

Haventt gotten to this yet. I'm not going to argue the blower isn't junk, as well as being extremely limited in function and design. now that we are playing the experience game...

I have close to 40 flyable model airplanes all running small electric motors. I have one setup that pulls 49 amps and over 500 watts at 12v's. This produces over 7lbs of thrust at over 80mph. I have well over 1500 hours this past year alones flying these small electric motors, and easily half that playing with amp loads, motor combinations and other variables. even though its a hobby, I am very knowledgeable with these types of things. I pull a watt meter out of my pocket 3-5 times a week.

If I go through the effort of pulling the motor out, a stock setup isn't going back in.you'd have to go to radio shack to come up with a worse system. I just wanted to temporarily bypass a bad switch to see if I could get by a couple weeks. not argue if something was broken.

This really hasn't been a priority though, since it has been tshirt weather and on the freeway, it easily pushes enough air through the vents to defrost the windows.

Thanks for all the help and schematics.