see this steps and fix it use the VOM or DVOM. God bless youThe Cause:
Most likely no voltage
to the headlights because of a bad headlight relay, fuse, module,
headlight switch, dimmer switch or wiring fault.
To figure out what's causing your problem, start by inspecting
the main fuse for the headlight circuit. See your Owners Manual for the
location of this fuse. It is often located in the power center in the
engine compartment, but may also be in the fuse panel under the dash.
If the fuse has blown, replace it with a new fuse (same amp rating) and
try again. If the fuse blows immediately, there is a short in the
headlight circuit that will have to be found and repaired before the
headlights will work. If the fuse does not blow and the headlights
work, problem solved (for now). There may be in intermittent short or
overload that caused the fuse to fail.
If the fuse if okay, use a volt meter or 12-volt test light to check
for power at the fuse. Most headlight circuits are on (powered) all the
time, so there should be voltage to the power side of the fuse. No
power at the fuse would indicate a wiring fault possibly in the fuse
block or in the wiring between the fuse block and the battery. You'll
need a wiring diagram to trace the wiring circuit and find the fault.
the fuse is okay and there is power, the next check would be to find
the headlight relay or control module. If the system uses a relay, pull
it out and shake it. If anything inside rattles, replace the relay.
Or buy another relay and plug that in to see if that restores power to
On systems that use a module control module or daytime running lamps,
about all you can do is eliminate other possibilities such as wiring
faults, a bad relay or headlight switch first. If the module is getting
power when the headlight switch is turned on, but the headlights fail to
come on, the problem is likely a bad module. The module may be located
in the front area of the engine compartment (common on Fords), under
the dash or elsewhere in the front of the vehicle. You will probably
need to refer to the vehicle service literature to find the module's
If the headlight relay or module do not receive voltage when the
headlight switch is turned on, a bad switch is your problem. Switches
get a lot of wear and tear, so it's not unusual for a switch to wear out
after many years of service. Replacing a headlight switch can be
difficult depending on whether is it located in the instrument panel or
on the steering column.
If your headlights work on low beam, but you have no high beam, or
they work on high beam but there is no low beam, the most likely cause
is a bad dimmer switch. The dimmer switch is integrated into the
steering column mounted headlight switch on most vehicles, so if the
dimmer is not working, you will have to replace the entire switch.
attempt to replace a steering column mounted
headlight switch without first disconnecting the battery and waiting at
least 20 minutes for the capacitors in the airbag circuit to discharge.
The steering wheel will have to come off to replace the switch.
Crossing up the wrong wires in the steering column could set off the air
bag and cause personal injury.
If a headlight switch looks like it will be difficult to replace,
don't try to do it yourself. Take your car to a dealer or repair shop
and have them replace the switch for you.