All models use halogen headlights. Bulbs can be replaced without disturbing the lens assembly (headlamp module). Some models have a single combination high/low bulb, while others use separate bulbs for each application.Aiming
The headlights must be properly aimed to provide the best, safest road illumination. The lights should be checked for proper aim and adjusted as necessary. Certain state and local authorities have requirements for headlight aiming; these should be checked before adjustment is made.
Headlight adjustment may be temporarily made using a wall, as described below, or on the rear of another vehicle. When adjusted, the lights should not glare in oncoming car or truck windshields, nor should they illuminate the passenger compartment of vehicles driving in front of you. These adjustments are rough and should always be fine-tuned by a repair shop that is equipped with headlight aiming tools. Improper adjustments may be both dangerous and illegal.
Two adjusting screws provide the horizontal and vertical aiming of each headlight. These screws move the retaining ring and adjusting plate against the tension of a coil spring.
The vertical (up and down) adjustment screw will be near the center of the headlight at the top or bottom of the assembly. The horizontal (left and right) adjustment screw will be on the side of the headlight at the top or bottom of the assembly.
- Park the vehicle on a level surface, with the fuel tank full and with the vehicle with an average load if one is normally carried.
- Be sure all tires are properly inflated.
- Bounce the truck up and down to center the suspension.
- The vehicle should be facing a wall that is no less than 6 feet (1.8m) high and 12 feet (3.7m) wide. The front of the vehicle should be about 25 feet from the wall.
Make headlight alignment marks on the wall according to the following parameters:
- On the wall, mark the exact the center of the vehicle with a vertical line.
- Measure the distance from the center of the vehicle to the center of each headlight. Transfer these measurements to the wall with vertical lines.
- Measure the distance from the floor to the center of the headlights and mark this on the wall with a horizontal line.
- Where the headlamp vertical lines and horizontal line meet on the wall is the "headlamp centerline." This will be the basis point for the adjustment.
- If aiming is to be performed outdoors, it is advisable to wait until dusk in order to properly see the headlight beams on the wall. If done in a garage, darken the area around the wall as much as possible by closing shades or hanging cloth over the windows.
Turn the headlights
and put on the low beam. Note the position of the pattern.
A properly aimed low beam will put the top edge of the high-intensity pattern ("hot spot") about 2 in. (50mm) above or below the horizontal headlamp centerline.
- Use the vertical and horizontal adjustment screws to move the pattern as required. Adjusting the low beam correctly ensures that high beam adjustment will be correct.
- Be sure that both headlamps have the exact same adjustment.
- Open the hood.
- Unfasten the locking ring (turn CCW) which secures the bulb and socket assembly, then withdraw the assembly rearward.
- If necessary, gently pry the socket's retaining clip over the projection on the bulb (use care not to break the clip.) Pull the bulb from the socket.
- Before installing a light bulb into the socket, ensure that all electrical contact surfaces are free of corrosion or dirt.
- Line up the replacement headlight bulb with the socket. Firmly push the bulb onto the socket until the spring clip latches over the bulb's projection.
- To ensure that the replacement bulb functions properly, activate the applicable switch to illuminate the bulb which was just replaced. (If this is a combination low and high beam bulb, be sure to check both intensities.) If the replacement light bulb does not illuminate, either it too is faulty or there is a problem in the bulb circuit or switch. Correct if necessary.
- Position the headlight bulb and secure it with the locking ring (turn CW).
- Close the hood.
- Fog lights have replaceable bulbs.
- Reach behind the fog lamp housing and turn the bulb assembly 1 / 4 of a turn CCW, and then pull it out.
- Pull the bulb out of the connector.
- Clean the bulb glass surfaces.
- Before installing the light bulb into the metal contacts, ensure that all electrical conducting surfaces are free of corrosion or dirt.
- Push the new bulb into the connector.
- Insert the bulb assembly into the lens and turn CW to lock.
- To ensure that the replacement bulb functions properly, activate the applicable switch to illuminate the bulb which was just replaced. If the replacement light bulb does not illuminate, either it is faulty or there is a problem in the bulb circuit or switch. Correct as necessary.
Bulb replacement does not require removal of the headlamp module. Removal will only be required if the module has been damaged. Several types of assembly are fitted depending on model and year. Refer to the illustrations for assembly details.
- Raise the hood.
- Remove the push-in fastener attaching the seal to the radiator closure panel, if fitted.
- RAM: remove the screw securing the turn/park lamp module to the headlamp module. Remove the turn/park lamp module.
- All: remove the screws attaching the headlamp module and remove the module.
- Disconnect the bulb wiring.
- Installation is the reverse of removal.