No low beams

[rob194]

Hello everyone, I am having problems on our 2018 XLT. We have the high beams but no low beams. I checked through the fuse panel and did not see a dedicated fuse. Has anyone had similar problem?

Thanks.

 

[Mr Big]

Could be the Multifunction switch on the column.
low beams and high beams may have separate circuits. Could be a bad relay, loose wire, harness plug or ground.
Did you check the owner's manual for fuse definitions for low and high beams or relays?

 

[Fizzy]

Could be the Multifunction switch on the column.
low beams and high beams may have separate circuits. Could be a bad relay, loose wire, harness plug or ground.
Did you check the owner's manual for fuse definitions for low and high beams or relays?

I checked yesterday and there’s no fuse or relay for the headlights named in the manual. It must be part of another circuit such as the BCM.

When I googled because I thought this was very odd, there’s threads in this forum and others complaining about exactly this - there’s no fuse for the headlights.

 

[bb37]

Here's the wiring diagram for a 2018 Expedition with halogen headlamps. Fuse F25 (50 amps) protects the left headlamps; fuse F76 protects the right headlamps.


There are two wiring diagrams for the 2018 with LED headlamps, one for left side (fuse F25) and one for right side (fuse F76).



In all cases, the low beam and high beam on one side are on the same fuse. If your high beams work and the low beams don't, then I'd suspect a problem in the Body Control Module (BCM) or in the communications to the BCM. The headlamp switch on the instrument panel is hardwired to the BCM. But, the steering column stalk is wired to the Steering Column Control Module which talks to the BCM over the CANbus. Note that the automatic headlamps also figure into this.

 

[Mr Big]

I think the OP has a 2020 Platinum, HD Tow, Star White Tri-Coat <----

 

[Fizzy]

I think the OP has a 2020 Platinum, HD Tow, Star White Tri-Coat <----

I am not the OP.

 

[Mr Big]

I am not the OP.

AHH, well according to the schematics, the fuses are located in the battery junction box. On my 2019, it is located near the battery.

 

[bb37]

I think the OP has a 2020 Platinum, HD Tow, Star White Tri-Coat <----

From the first post in this thread:

I am having problems on our 2018 XLT.

 

[Fizzy]

AHH, well according to the schematics, the fuses are located in the battery junction box. On my 2019, it is located near the battery.

And yet, the 2018 manual shows these for fuses 25 and 76. All this is to repeat what I said already - there are no dedicated headlight fuses. Those two fuses are for the entire BCM. Pulling them would not be advised.

As per @bb37 above - the fact the high beams work and not the low beams, indicates an issue unrelated to fuses.

 

[Mr Big]

This scematic shows fuses under the hood.