Steven L. Finberg

Recently I've noticed radio interfearance originating from the
standard heater temperature control. It is most noticeable
when listening to relatively weak AM stations. It is most
apparent when the Explorer is cold and the control fully
clockwise. The whinning interfearance can be "tuned" out
by moving the temp knob a bit but may drift back. It occurs
regardless of the other heater control positions.

Has any one else noticed this and chased down a solution?
Is a schematic of the "solid state" mixing door control available?

The truck is a 99 Explorer Sport with a 4L SOHC . The heater
has the standard 3 knob controls not the ETAC option.

*******************************************************************************
Steve Finberg W1GSL w1gsl@mit.edu
PO Box 397082 MIT Br Cambridge MA 02139-7082 617 258 3754
*******************************************************************************

Bill Hall

Steve,are you sure it is the heater control? Explorers are notorious for a
"whine" that some attribute to the fuel pump! My Icom 2100H will pick this
up on an intermittent basis and is big time irritating. I have not been able
to find the source. (99, 4.0) If you find a fix, would be interested in what
you find.
Bill
"Steven L. Finberg" <w1gsl@mit.edu> wrote in message
news:424010ba$0$573$b45e6eb0@senator-bedfellow.mit.edu...
> Recently I've noticed radio interfearance originating from the
> standard heater temperature control. It is most noticeable
> when listening to relatively weak AM stations. It is most
> apparent when the Explorer is cold and the control fully
> clockwise. The whinning interfearance can be "tuned" out
> by moving the temp knob a bit but may drift back. It occurs
> regardless of the other heater control positions.
>
> Has any one else noticed this and chased down a solution?
> Is a schematic of the "solid state" mixing door control available?
>
> The truck is a 99 Explorer Sport with a 4L SOHC . The heater
> has the standard 3 knob controls not the ETAC option.
>
> *******************************************************************************
> Steve Finberg W1GSL
> w1gsl@mit.edu
> PO Box 397082 MIT Br Cambridge MA 02139-7082 617 258
> 3754
> *******************************************************************************
>

Vic Klein

With the major use of computers in modern vehicles, there are lots of noises
associated with controls. No fix for the original poster, but the fuel pump
noise is pretty easy. Ford has a TSB and a module they can install on the
furl pump motor to greatly reduce that noise. Or, you can build your own
filter with bypass caps and common-mode filtering with ferrite cores.

=Vic=
Bear Gap, PA

"Bill Hall" <bhallc21@verizon.net> wrote in message
news:IYX%d.6572$191.716@trnddc02...
> Steve,are you sure it is the heater control? Explorers are notorious for a
> "whine" that some attribute to the fuel pump! My Icom 2100H will pick this
> up on an intermittent basis and is big time irritating. I have not been
> able to find the source. (99, 4.0) If you find a fix, would be interested
> in what you find.
> Bill
> "Steven L. Finberg" <w1gsl@mit.edu> wrote in message
> news:424010ba$0$573$b45e6eb0@senator-bedfellow.mit.edu...
>> Recently I've noticed radio interfearance originating from the
>> standard heater temperature control. It is most noticeable
>> when listening to relatively weak AM stations. It is most
>> apparent when the Explorer is cold and the control fully
>> clockwise. The whinning interfearance can be "tuned" out
>> by moving the temp knob a bit but may drift back. It occurs
>> regardless of the other heater control positions.
>>
>> Has any one else noticed this and chased down a solution?
>> Is a schematic of the "solid state" mixing door control available?
>>
>> The truck is a 99 Explorer Sport with a 4L SOHC . The heater
>> has the standard 3 knob controls not the ETAC option.
>>
>> *******************************************************************************
>> Steve Finberg W1GSL w1gsl@mit.edu
>> PO Box 397082 MIT Br Cambridge MA 02139-7082 617 258
>> 3754
>> *******************************************************************************
>>
>
>