> My wife's Expedition has an intermittent problem with the left turn
> signal. Occasionally, when the turn signal is applied, the 'clicking' (is
> that a technical term?) speed doubles, and the rear light does not blink
> (nor illuminate at all). After a few days, the problem goes away. I've
> replaced the bulb, but that doesn't appear to be the issue.
>
> Can anyone suggest where I might start looking for this problem?
either the bulb is burned out(when that happens) in your case the bulb might be loose... or its the blinker under the dash.. most fords have one for each side.... the contacts are arcing so that is why no light flashing, just the noise of a fast click......