Author Topic: Heater box resistor question (Read 731 times)

monkeystash · « **on:** January, 25, 2011, 08:52:36 PM »

On the right side of the photo is the new resistor, and the old on the left. The wire springs touch on the new one, but don't on the old one. Does it matter? I'm concerned it might cause a short if they are touching, but I'm ignorant at best with electricity. Thanks.

ZFORCE · « **Reply #1 on:** January, 25, 2011, 09:57:11 PM »

They are not supposed to touch. Bend them so that they aren't. The resistors change the speed of the blower motor. More turns of wire equals higher resistance and thus a slower blower speed. If they touch, it may change the path of electricity and thus the blower speed. It probably wouldn't do much else, but they are not supposed to touch. Simple fix.

B67FSTB · « **Reply #2 on:** January, 26, 2011, 02:03:54 AM »

Quote from: ZFORCE on January, 25, 2011, 09:57:11 PM

They are not supposed to touch. Bend them so that they aren't. The resistors change the speed of the blower motor. More turns of wire equals higher resistance and thus a slower blower speed. If they touch, it may change the path of electricity and thus the blower speed. It probably wouldn't do much else, but they are not supposed to touch. Simple fix.

+1 here and be sure that the control panel has a sufficient ground connection.
The blower motor " finds " his ground through the control panel.

janschutz · « **Reply #3 on:** January, 26, 2011, 06:52:47 AM »

Quote from: ZFORCE on January, 25, 2011, 09:57:11 PM

... The resistors change the speed of the blower motor. More turns of wire equals higher resistance and thus a slower blower speed. ...

The new resistor has more turns than the original. I noticed that when I replaced my heater resistor that my fan ran slower. Can the heater resistor be by passed making the fan run full speed all the time when all or will it be pulling too much current?

Horseplay · « **Reply #4 on:** January, 26, 2011, 07:28:31 AM »

Measure the ohms resistance of the new piece and compare that to the original spec. You can shorten the "spring" to reduce the resistance (or just get another properly rated resistor). If you eliminate it altogether you will be sending full voltage to the motor which will most likely be too much and hurt/kill it.

B67FSTB · « **Reply #5 on:** January, 26, 2011, 07:40:23 AM »

IIRC when you have 2 resistors then you have 3 different speeds of the blower motor.
Highest resistor is first speed , lowest resistor is second speed and NO resistor is full speed of the blower motor.
Keep in mind that the + pole of the blower motor directly connected is to a positive terminal and that the - pole from the blower motor is conected to the resistors and from there on it goes , through different wires , to the control panel to find its ground.Which of those wires is grounded determines speed of the blower motor .As said earlier on , grounding the control panel is very important !!