2002 gmc envoy
You could check fuse's F7 & F8 located in the SJB - smart junction box , both are 10amp.. This is ford's BCM - body control module ,if you know or heard of these . a computer ! The SJB turns on the headlamps when it receives input signal from the switch . If the fuse's are not blown your best bet would be to take it to ford dealer or someother qualified repair shop . May have DTC'S -diagnostic trouble codes stored in the SJB .The SJB test's these electrical circuits for opens ,shorts to power , to ground etc....
Principles of Operation
The smart junction box (SJB) monitors the headlamp switch position by sending voltage reference signals on multiple circuits to the headlamp switch. At any given time, one of the signal circuits is routed to ground. If the SJB does not detect any of the inputs to the headlamp switch is active (routed to ground) for 5 seconds, the SJB turns on the exterior lights and keeps them on for 10 minutes after the ignition switch is turned off (or 10 minutes from the time the SJB does not detect any headlamp switch input if the ignition switch was already off). If the SJB detects multiple circuits short to ground, the SJB implements a planned strategy depending on the multiple inputs received. If either of these situations occur, the SJB should NOT be ruled immediately as being at fault. This is normal behavior of the SJB design as it has detected a fault with the inputs from the headlamp switch.
The SJB also monitors the multifunction switch for a flash-to-pass or high beam request. There are 2 voltage reference circuits which monitor this. When the multifunction switch is in the FLASH-TO-PASS or HIGH BEAM position, the voltage signal is routed to ground.
NOTE: The flash-to-pass feature does not require any input from the headlamp switch.
When the SJB receives an input requesting the headlamps on, the SJB supplies voltage to the low beams. If the low beams are on and the SJB receives a request for high beams (or just a flash-to-pass request), the SJB energizes an internal relay which routes voltage to the headlamps.
Field-Effect Transistor (FET) Protection
The SJB utilizes a FET protective circuit strategy for many of its outputs (for example, the headlamp output circuit). Output loads (current level) are monitored for excessive current (typically short circuits) and are shut down (turns off the voltage or ground provided by the module) when a fault is detected. A continuous DTC is stored at that time for the fault. The circuit will then reset after a customer demand of the function (switching the component on, battery saver being energized). When an excessive circuit load occurs several times, the module shuts down the output until a repair procedure is carried out. At the same time, the continuous DTC that was stored on the first failure will not clear by a command to clear the continuous DTCs. The module will not allow this code to be cleared or the circuit restored to normal operation until a successful on-demand self-test proves that the fault has been repaired. After the on-demand self-test has successfully completed (no on-demand DTCs present), the continuous DTC will have been cleared and the circuit function will return.
Each circuit has three predefined levels of short circuit tolerance established in the module based on each circuits' capability. When the first or second level is reached, the continuous DTC associated with the circuit sets along with DTC B106E. These DTCs may be cleared using the Clear DTC operation on the scan tool as long as the fault itself has been corrected. If any of the circuits are shorted past the third level, then B106F sets along with the associated continuous DTC. This DTC cannot be cleared and the module must be replaced.
The SJB FET protected output circuits for the headlamp system are for the LH low beam output and the RH low beam output circuits.
×
SOURCE: 2001 Ford Focus - High beam / low beam problem with headlights
just replace the dimmer switch under the column its wore out on the low beam side
Testimonial: "It's great to know that there's not a whole lot more to check! I wouldn't have guessed I was so close. Thanks!"
SOURCE: drivers side low beam headlight not working. its not a blown fuse
The headlight bulb has burned out, replace with correct part number and it should work fine. Contact me at FixYa if you need anymore assistance. Thank you.
SOURCE: I have a 2006 ford
Both your low beam and your high beam is protected by the same fuse, so it makes sense that the fuse is OK if the high beam is working on the passenger side. There are 3 fuses for the headlamps. Fuse #13 in the Battery Junction Box (20 Amp). If this fuse is blown, the headlamp relay will not have any power and neither high nor low beam on either side will work (you will have no headlamps at all) Then there is Fuses #2 and #3 (15 Amp) in the Battery Junction Box. #2 goes to the left low and high beam and #3 goes to the right low and high beam.
The headlamp switch uses a SINGLE CIRCUIT to control BOTH sides at the same time, so if one side works, the switch cannot be the problem. The headlamp relay provides power for fuses #2 and #3 and we already ascertained that these fuses must have power since we have working lights on both sides, so the relay cannot be the problem. A replacement bulb has already been tried, so that pretty much leaves us with a bad lamp socket. (Most likely cause) or a bad connection at splice #S122, which is located in the main wiring harness near the breakout for the left headlamp. (RED/BLACK wire)
773 views
Usually answered in minutes!
NOTE: Due to varying wattage ratings and resulting current draw, certain aftermarket headlamp bulbs may cause the SJB to shut down the short circuit protection, resulting in the low beams becoming inoperative.
Verify that the bulbs meet Ford specifications. If the bulbs do not meet Ford specifications, install the correct bulbs. Run the on-demand self-test (required to clear certain DTCs and reset the SJB). Correct any unresolved DTCs. Clear all DTCs. Test the system for normal operation.
Both low beams are inoperative
NOTE: Due to varying wattage ratings and resulting current draw, certain aftermarket headlamp bulbs may cause the SJB to shut down the short circuit protection, resulting in the low beams becoming inoperative.
Incorrect bulbs
Verify that the bulbs meet Ford specifications. If the bulbs do not meet Ford specifications, install the correct bulbs. Run the on-demand self-test (required to clear certain DTCs and reset the SJB). Correct any unresolved DTCs. Clear all DTCs. Test the system for normal operation.
SJB
CHECK for recorded SJB DTCs.
If DTCs are present, REFER to the Diagnostic Trouble Code (DTC) Charts in this section.
If no DTCs are present, INSTALL a new SJB. REFER to Section 419-10 . TEST the system for normal operation.
×