Low Beams not working - Hi beams OK
#16
01-11-2017, 06:37 AM
Hotshot
My headligths went bad when I put an HID to it. Went back to OEM lights but my low beam are not working. I replace the light switch and the MFS, and check all the fuses and they're good, but did not fix the problem. What you guys think it might be the problem I'm running into Olin here????
#17
02-17-2018, 04:51 AM
ill jump in here for my first post
few months ago we were getting a piddiddle on the 14 f350. Pulled the Fisher iso module, checked fuses, bulbs, wires, sockets etc nothing
pulled the MFS from the 13 450, nothing. same w headlight switch nothing. was in a pinch, so i jumped power from the working light to the one that wouldnt work.
that worked, however. occasionally youd turn the headlights on, they wouldnt light, but if you turned the switch off and on again, theyd work, so - we ran it.
now i have no low beams at all.
have checked:
fuses
swapped out Headlight switch and MFS with working truck
checked for power to sockets, nada
high beams work and activate with MFS, but wont lock on..
problems are the same with the plow iso module bypassed
is there a known computer board problem? guy at the parts store seemed to think so.
few months ago we were getting a piddiddle on the 14 f350. Pulled the Fisher iso module, checked fuses, bulbs, wires, sockets etc nothing
pulled the MFS from the 13 450, nothing. same w headlight switch nothing. was in a pinch, so i jumped power from the working light to the one that wouldnt work.
that worked, however. occasionally youd turn the headlights on, they wouldnt light, but if you turned the switch off and on again, theyd work, so - we ran it.
now i have no low beams at all.
have checked:
fuses
swapped out Headlight switch and MFS with working truck
checked for power to sockets, nada
high beams work and activate with MFS, but wont lock on..
problems are the same with the plow iso module bypassed
is there a known computer board problem? guy at the parts store seemed to think so.
#18
02-17-2018, 04:53 AM
#19
02-17-2018, 07:36 AM
Ok, you are working on a 2014 f350 with a plow setup? And now you have no lowbeams on the truck itself?
Glancing at the diagrams, there is a body control module somewhere in the truck. This is where the fuses are located for the individual headlight filaments, f17=left lowbeam, f39=both highbeams, f16=right lowbeam. These fuse locations would also be a good place to probe with a testlight.
Right after these fuses the power goes into the body control module, and there is a solid state switch inside the body control module that does the actual switching of the headlights. If anything was going to have a tendency to burn out, I would think it would be these solid state switches inside the body control module.
Coming out of this module, the left lowbeam is a brown/blue, right lowbeam is a blue/green. Unfortunately to see if the body control module is getting the correct signals, you probably need the truck hooked to a scanner. The multi-function switch communicates to the body control module through two communication wires. This is how the multi-function switch tells the solid state switches inside the body control module to activate the low and high beams.
Glancing at the diagrams, there is a body control module somewhere in the truck. This is where the fuses are located for the individual headlight filaments, f17=left lowbeam, f39=both highbeams, f16=right lowbeam. These fuse locations would also be a good place to probe with a testlight.
Right after these fuses the power goes into the body control module, and there is a solid state switch inside the body control module that does the actual switching of the headlights. If anything was going to have a tendency to burn out, I would think it would be these solid state switches inside the body control module.
Coming out of this module, the left lowbeam is a brown/blue, right lowbeam is a blue/green. Unfortunately to see if the body control module is getting the correct signals, you probably need the truck hooked to a scanner. The multi-function switch communicates to the body control module through two communication wires. This is how the multi-function switch tells the solid state switches inside the body control module to activate the low and high beams.
#20
02-17-2018, 08:51 AM
Ok, you are working on a 2014 f350 with a plow setup? And now you have no lowbeams on the truck itself?
Glancing at the diagrams, there is a body control module somewhere in the truck. This is where the fuses are located for the individual headlight filaments, f17=left lowbeam, f39=both highbeams, f16=right lowbeam. These fuse locations would also be a good place to probe with a testlight.
Right after these fuses the power goes into the body control module, and there is a solid state switch inside the body control module that does the actual switching of the headlights. If anything was going to have a tendency to burn out, I would think it would be these solid state switches inside the body control module.
Coming out of this module, the left lowbeam is a brown/blue, right lowbeam is a blue/green. Unfortunately to see if the body control module is getting the correct signals, you probably need the truck hooked to a scanner. The multi-function switch communicates to the body control module through two communication wires. This is how the multi-function switch tells the solid state switches inside the body control module to activate the low and high beams.
Glancing at the diagrams, there is a body control module somewhere in the truck. This is where the fuses are located for the individual headlight filaments, f17=left lowbeam, f39=both highbeams, f16=right lowbeam. These fuse locations would also be a good place to probe with a testlight.
Right after these fuses the power goes into the body control module, and there is a solid state switch inside the body control module that does the actual switching of the headlights. If anything was going to have a tendency to burn out, I would think it would be these solid state switches inside the body control module.
Coming out of this module, the left lowbeam is a brown/blue, right lowbeam is a blue/green. Unfortunately to see if the body control module is getting the correct signals, you probably need the truck hooked to a scanner. The multi-function switch communicates to the body control module through two communication wires. This is how the multi-function switch tells the solid state switches inside the body control module to activate the low and high beams.
Yeah. Power in the fuse box is fine
I swapped out he isolation module for good measure, still nothing. Happens with or without the plow plugged in
must be in that bcm
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