"Bob W." <rwalter@engineer.com> wrote:
> Rudy,
> One other idea. Try using your handheld transmitter outside of the
> car with the car turned off and walking up and down your driveway.
> That should give you an idea if the car is interfering or not.

Bob, you did not pay close attention to my original post which I
started as so:
"I noticed lately that the effective range of my garage door opener is
greatly reduced when the engine is running vis-a-vis when it is not."
That makes it obvious that it is something in the running engine.
However, I may have found the source. Something in the heater control
unit because when no button is pushed , the problem seems to be gone.
This could explain why I have been experiencing the problem only
recently. Because I have one of the heater buttons pressed only since
the cold weather. Otherwise none of the heater buttons are pressed. I
need to experiment more with this discovery but it looks like a
promising lead. However I still am greatful for the helpful tips you
all suggested.

Rudy