Wtf? Is my tow package missing left brake light fuse fitting?

[charwest]

My wife and I went today to borrow a U-Haul trailer for the second time since we bought the truck. We did this once before and I don’t remember whether the lights worked. The person checking may not have checked well.

This time the rear left trailer signal doesn’t work and we traced it back to the truck itself. There is no current at the plug. We have factory installed tow package that came with the. We truck and the right side works as expected

So then I go looking for a fuse that is out, and there is no actual fuse in the slot labeled left light. So then I take one of our other fuses to put it in that slot, and it doesn’t actually even have the fuse fins. Just missing fins. (These are female fuses, or whatever the correct term is). There are small slots where I assume fins go that I tried shorting out with a piece of wire but isn’t working.

Obviously I’ll talk to the Ford dealer when we get a chance, but I’m wondering if I’m missing something?

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[charwest]

This is where thet

My wife and I went today to borrow a U-Haul trailer for the second time since we bought the truck. We did this once before and I don’t remember whether the lights worked. The person checking may not have checked well.

This time the rear left trailer signal doesn’t work and we traced it back to the truck itself. There is no current at the plug. We have factory installed tow package that came with the. We truck and the right side works as expected

So then I go looking for a fuse that is out, and there is no actual fuse in the slot labeled left light. So then I take one of our other fuses to put it in that slot, and it doesn’t actually even have the fuse fins. Just missing fins. (These are female fuses, or whatever the correct term is). There are small slots where I assume fins go that I tried shorting out with a piece of wire but isn’t working.

Obviously I’ll talk to the Ford dealer when we get a chance, but I’m wondering if I’m missing something?

This is where there should be a fuse, as far as I can tell

 

[BDUb]

Sounds about par for the course, I have a tow package and it's missing the receiver. Ford or the dealerships have been messing that package up.

 

[AZLightning]

What makes this really weird is that all Rangers not just tow package have the 4 flat plug (which every uhaul I've ever seen use) so all Rangers should have that fuse. Also no one who has added the 7 round had mentioned having to go back and a fuse that I remember.

 

[Big Blue]

OK, a couple things. Trucks with tow package should have a trailer module, it shows up in Forscan as TRM. the trailer lights are controlled by this module and I believe do not use the fuses in the fuse panel. This module also controls the voltage to the 12 volt charging pin in the 7 pin connector. Without the tow package the lights are controlled by relays and fuses in the fuse panel.

Also, how did you check the plug to determine you didn't have voltage. Trying to check any thing at the plug in the bumper is made almost impossible as the trailer module will not activate any of the connections unless a trailer is plugged in and detected. So if you don't get the trailer detected warning on your dash the plugs may appear to be dead.

Just saying this because the problem still could have been with the trailer and not the truck. Unless you tried a couple trailers and had the same problem. I know there were some issues with some 2019 XLs without the tow package not having the trailer module and missing the wiring for the brake controller. But, I haven't heard of any issues with trucks that had the factory tow package.

 

[charwest]

OK, a couple things. Trucks with tow package should have a trailer module, it shows up in Forscan as TRM. the trailer lights are controlled by this module and I believe do not use the fuses in the fuse panel. This module also controls the voltage to the 12 volt charging pin in the 7 pin connector. Without the tow package the lights are controlled by relays and fuses in the fuse panel.

Also, how did you check the plug to determine you didn't have voltage. Trying to check any thing at the plug in the bumper is made almost impossible as the trailer module will not activate any of the connections unless a trailer is plugged in and detected. So if you don't get the trailer detected warning on your dash the plugs may appear to be dead.

Just saying this because the problem still could have been with the trailer and not the truck. Unless you tried a couple trailers and had the same problem. I know there were some issues with some 2019 XLs without the tow package not having the trailer module and missing the wiring for the brake controller. But, I haven't heard of any issues with trucks that had the factory tow package.

this is over my head, admittedly, and i would have to do some homework before speaking to your comments accurately.

when we hooked up the uhaul trailer to the four flat plug the right sided lights worked correctly (hazards, indicators) but the left did not. the uhaul person initially thought it was his trailer, but then brought out a voltage sensor and found that the truck did not have voltage at the left light on either the flat four or the 7 round connectors. based on that, i got out the manual from the glovebox, spent a bunch of time figuring out how to access the top fuses, then the bottom fuses, and saw that the fuse that was labeled left trailer in the manual was just not there. i assumed this was the problem, although perhaps there is more to it as you say. one thing i CAN say confidently is that that manual leaves a lot to be desired. it seems like 50% of the time me and my wife go to the manual to find some basic piece of information, its not there, or seemingly seems to have been copied from some earlier model or the f150 manual or something that just doesnt sound right.

anyways, we then rented a uhaul truck to pull the uhaul trailer. the guy said it worked, although i guess i admit i didnt actually go back there and check. but he was pretty anal retentive from the safety perspective, so it would have been surprising if he made a big fuss about not letting us take the trailer out with a rear light out, and then turn around and send us out on the highway with a rear light out.

 

[Big Blue]

this is over my head, admittedly, and i would have to do some homework before speaking to your comments accurately.

when we hooked up the uhaul trailer to the four flat plug the right sided lights worked correctly (hazards, indicators) but the left did not. the uhaul person initially thought it was his trailer, but then brought out a voltage sensor and found that the truck did not have voltage at the left light on either the flat four or the 7 round connectors. based on that, i got out the manual from the glovebox, spent a bunch of time figuring out how to access the top fuses, then the bottom fuses, and saw that the fuse that was labeled left trailer in the manual was just not there. i assumed this was the problem, although perhaps there is more to it as you say. one thing i CAN say confidently is that that manual leaves a lot to be desired. it seems like 50% of the time me and my wife go to the manual to find some basic piece of information, its not there, or seemingly seems to have been copied from some earlier model or the f150 manual or something that just doesnt sound right.

anyways, we then rented a uhaul truck to pull the uhaul trailer. the guy said it worked, although i guess i admit i didnt actually go back there and check. but he was pretty anal retentive from the safety perspective, so it would have been surprising if he made a big fuss about not letting us take the trailer out with a rear light out, and then turn around and send us out on the highway with a rear light out.

I am not saying there isn't a problem with your truck and that there was with the trailer. You still should have the dealer check it out, hopefully your still under warranty yet. I just do know that our trucks are very different about how the trailer connectors work because of how they tie into the various other systems in the truck. So trying to test them without having a trailer connected and the truck recognizing the trailer can give erroneous results. A lot of people have thought their 12 volt charging pin was not working because it is only activated when the truck sees the trailer.

 

[deleriumtremor]

This is where thet

This is where there should be a fuse, as far as I can tell

I just went out and checked my 2022 XLT (with optional factory trailer tow package). I checked the 7 and 4 lead plugs and everything is operational.

I then went and looked for the trailer fuses and I don't have the left or right trailer turn/stop signal fuses populated in my fuse box as well and the relays on the top side aren't there as well (per the owners manual diagram).

My only conclusion is the relay and fuse function is managed differently than the owners manual would indicate (perhaps a design change along the way that never got reflected in the owners manual text and diagrams).

Your dealer will know where the tow fuses and relays are managed from and likely will be able to find the fault.

PS - I highly recommend anyone wondering about their relay and fuse boxes go through the process of learning how to remove the top and bottom relay/fuse boxes and covers for the box in the engine compartment. It can seem quite daunting the first time through, but once you do it the first time and learn how all the tabs and keepers work, it is quite simple.

 

[Big Blue]

My only conclusion is the relay and fuse function is managed differently than the owners manual would indicate (perhaps a design change along the way that never got reflected in the owners manual text and diagrams).

PS - I highly recommend anyone wondering about their relay and fuse boxes go through the process of learning how to remove the top and bottom relay/fuse boxes and covers for the box in the engine compartment. It can seem quite daunting the first time through, but once you do it the first time and learn how all the tabs and keepers work, it is quite simple.

As I mentioned with the factory tow package the trailer light functions are managed by the TRailer Module. I have an XLT and it may be different with XLs but some without the tow package do not have the TRM. Those trucks will use relays and fuses in the fuse box to control the trailer lights. If you have the TRM those relays and fuses will not be there. The whole idea is that the trailer lights are isolated from the trucks taillights. The easiest way to tell if your truck has the TRM is to fire up Forscan and see if it shows in the list.

I agree with you the factory manual leaves much to be desired, this is just one of many points.
Getting to the lower fuses is another one. So, your point about practice is a good one.

 

[Trigganometry]

As I mentioned with the factory tow package the trailer light functions are managed by the TRailer Module. I have an XLT and it may be different with XLs but some without the tow package do not have the TRM. Those trucks will use relays and fuses in the fuse box to control the trailer lights. If you have the TRM those relays and fuses will not be there. The whole idea is that the trailer lights are isolated from the trucks taillights. The easiest way to tell if your truck has the TRM is to fire up Forscan and see if it shows in the list.

I agree with you the factory manual leaves much to be desired, this is just one of many points.
Getting to the lower fuses is another one. So, your point about practice is a good one.

I have an XLT with bliss. That throws a whole different spin on this. What you’re saying makes sense because it makes it modular in a way that features like this can be added or subtracted without having totally different systems to do the same thing.

 

[deleriumtremor]

As I mentioned with the factory tow package the trailer light functions are managed by the TRailer Module. I have an XLT and it may be different with XLs but some without the tow package do not have the TRM. Those trucks will use relays and fuses in the fuse box to control the trailer lights. If you have the TRM those relays and fuses will not be there. The whole idea is that the trailer lights are isolated from the trucks taillights. The easiest way to tell if your truck has the TRM is to fire up Forscan and see if it shows in the list.

I agree with you the factory manual leaves much to be desired, this is just one of many points.
Getting to the lower fuses is another one. So, your point about practice is a good one.

Makes total sense. The other truck I had with a factory tow package also had a separate Tow Module that managed the trailer lights, brakes, etc. It was very confusing in that manufacturers docs as some model and/or years had the Tow Module logic embedded in a fuel management control module (I guess they has some extra pins and transistors in that module, so just used it), while in other model/years they had a separate module. None of any of that was documented in the owners manual.

 

[Chkls]

I've the same no trailer left turn signal problem. I've gone through the heart break of dealing with the fuse boxes and finding no fuses. I've pulled three different trailers with the same results. So, has anyone got the answer? Why doesn't my trailer left turn signal work?

 

[ControlNode]

I've the same no trailer left turn signal problem. I've gone through the heart break of dealing with the fuse boxes and finding no fuses. I've pulled three different trailers with the same results. So, has anyone got the answer? Why doesn't my trailer left turn signal work?

Does your truck have the tow package? If you do, it will use two fuses to power the TRM, those being F73 and F87. The parking lights are controlled by fuse F71 and a relay still though. I actually suspect that the TRM looks for continuity to ground on the parking light circuit to determine if the trailer is connected. I would highly suggest using ForScan to see if the TRM is reporting any errors.

If you do not have the tow package, it should use F56 (left) and F63 (right) and F71 (park) along with relays that are part of the BCM as best I can tell.

Also, I think you can force the +12V output on by turning on tow mode manually with the button on the console.

 

[Chkls]

My wife and I went today to borrow a U-Haul trailer for the second time since we bought the truck. We did this once before and I don’t remember whether the lights worked. The person checking may not have checked well.

This time the rear left trailer signal doesn’t work and we traced it back to the truck itself. There is no current at the plug. We have factory installed tow package that came with the. We truck and the right side works as expected

So then I go looking for a fuse that is out, and there is no actual fuse in the slot labeled left light. So then I take one of our other fuses to put it in that slot, and it doesn’t actually even have the fuse fins. Just missing fins. (These are female fuses, or whatever the correct term is). There are small slots where I assume fins go that I tried shorting out with a piece of wire but isn’t working.

Obviously I’ll talk to the Ford dealer when we get a chance, but I’m wondering if I’m missing something?

Did you ever get this issue resolved?

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