FAN DIAL A/C or HEATER

1999 CIVIC DIAL KNOB, FAN STAYS ON LOW, IN ALL SETTINGS EXECPT THE HIGHEST,
EVEN IN THE OFF POSITION. A/C WORKS FINE. ANY SUGGESTIONS ON HOW OR WHERE
TO START LOOKING TO TRUOBLESHOOT GREATLY APPRECIATED. THANK YOU.

 

1) Trade in that 50's teletype you're using and get a terminal that supports
lower case. Most humans find all uppercase to be an eyesore.

2) Get a repair book or manual with an electrical diagram. Visit the
library if you're too damn cheap to buy one. Or visit a dealership and ask
to look at a shop manual.

If the fan is on low even in the "off" position, I think you have a bad
fan switch -- the thing sitting behind the knob you flick to change
speeds.

There's also a "resistor" block with it's business end in the air flow
probably on the fan itself or not too far from it. It's 2 or 3 coils of
wire that restrict the electrical current flow in order to arrive at the
slower fan speeds. All you'll see until you remove it is an about 2" square
with a wiring harness pluged into it with about 3-6 wires coming off it.

However, it's probably the switch that's bad.

 

Are you saying the fan operates (low to hight) just fine in AC? That
does not make much sense, so I am assuming this is not the case.

Sounds like something is wrong in the switch because the 'off' position
is an open position under normal circumstances. Don't see how the fan's
resistor could possibly cause it to not turn off so that's not it.

Perhaps the common connection of the switch is permanently tied to one
of the contacts, maybe at the switch' connector.
In that case, switching to another setting may make a very small
difference in the speed of the fan motor, but you'll probably not
notice it.

Remco