It will mainly happen at cruising speeds. It does not show you on the dash on a 2006.
It means your engine MDS system (or 4 cylinder shut-down) is engaged. Means your saving fuel.
You will have to remove the entire dash to replace. There are screws that are only accessable if the dash is on the ground and upside down.
Down the dipstick tube.
Possibly the dash light dimmer, located next to the headlight switch, is turned down. Turn it to brighten the lights.
its down on the passenger side of the radiator... it is just a small aluminum cylinder....
Behind the passenger side cylinder head, sticks down into the bell housing
Behind the passenger side cylinder head, sticks down into the bell housing.
it's in the dash, the speedometer cable runs the speedometer and it connects to the back of the speedometer and it runs down to the back of the transmission case.
hook it to the speedometer behind the dash and route it through the firewall down to the transmission and hook it up to the tranny.
your alternator is going bad
On my 2006 Dodge Ram, I removed the glove box by pressing the outer sides of the glove box inwardly and then let the box drop down.
The dimmer control knob (usually the headlight knob) is turned down. Turn it to adjust the brightness