Motorhome headlights, sidelight and taillights fuse

[csltbr@gmail.com]

Hi, I have a 2017 Thor Motorhome (34J on Ford F53 Chassis), when I turn on the headlight, only 1 of the 2 headlights lightbulbs(2 on driver side and 2 on passenger side) on each side is on.
Also all the sidelights and taillights are not on at all.
I suspect it is a fuse problem, but no sure which one?

Any ideas?
Thanks in advance.
John

[Trophy1200]

Are you sure that the daytime running lights aren't on?

Normally you would have one main beam lamp and one dip lamp each side, but side and tail should light if the switch is set to headlamps.

Does your light switch have an auto position? If so and you're testing in daylight it could just be the DRL lighting, but it should still be one each side.

Turn the switch to headlamps when it's dark and see what light do and don't work.


You may not have DRLs in which case all of the above may be wrong, but at least it's worth a try before standing on your head searching for fuses.

[csltbr@gmail.com]

Hi,Kev,
Thank for your advise.
Unfortunately my RV doesn't have DRL.
John

Originally Posted by Trophy1200

Are you sure that the daytime running lights aren't on?

Normally you would have one main beam lamp and one dip lamp each side, but side and tail should light if the switch is set to headlamps.

Does your light switch have an auto position? If so and you're testing in daylight it could just be the DRL lighting, but it should still be one each side.

Turn the switch to headlamps when it's dark and see what light do and don't work.


You may not have DRLs in which case all of the above may be wrong, but at least it's worth a try before standing on your head searching for fuses.

[javelin]

I assume your 2017 34j is a Hurricane model class A? If yes then you could try the attached link to fuse records for the 2016 F53 chassis (Thor builds on previous year chassis typically). I just did a quick search for this info so not sure how accurate it is.....but if your parks are not working then try checking fuse 6 (20amp) in the Ford power distribution box located in the engine compartment typically central firewall area. (Scroll down link for the 2016 fuse info)

https://fuse-box.info/ford/ford-f-53...uses-and-relay


I assume most modern class A rigs would be equipped with DRL and they would come on when engine is running with transmission in gear and turn off when parks or headlights are on.

[csltbr@gmail.com]

Hi,Javelin,
You hit the nail on the head! Thank you.
Yes, Fuse 6 is burned, but once I replaced the fuse and turned on the light, the new fuse was burned again.
So it looks like there is short circuit somewhere.
Any idea how to find the location? I do have a multiple meter.

I really appreciate it.
John

Originally Posted by javelin

I assume your 2017 34j is a Hurricane model class A? If yes then you could try the attached link to fuse records for the 2016 F53 chassis (Thor builds on previous year chassis typically). I just did a quick search for this info so not sure how accurate it is.....but if your parks are not working then try checking fuse 6 (20amp) in the Ford power distribution box located in the engine compartment typically central firewall area. (Scroll down link for the 2016 fuse info)

https://fuse-box.info/ford/ford-f-53...uses-and-relay


I assume most modern class A rigs would be equipped with DRL and they would come on when engine is running with transmission in gear and turn off when parks or headlights are on.

[javelin]

Hi John, glad you confirmed the specific feeder fuse at least......and unfortunately also that you have a short circuit somewhere in your park/running lights system. I don’t have schematics for the F53 park light systems but I think after the 12vdc fuse feed passes through the main light switch (park on position) they go directly to the various park and running lamp locations. It would be nice to be able to isolate the lamp positions individually, but I am not sure where/if there is a common distribution tie point for the park wiring feeds near the main light switch. The short cct might even be something like a chafing body screw on the park wiring somewhere. Has there been any work done recently on or near any of the park or running light systems? If not, you might have to resort to removing lighting covers and inspecting the physical lamp socket connections for the short circuit. You don’t want to blow through a lot of expensive fuses so use your meter (or a 12vdc trouble lamp) to prove the short circuit to ground. It is a PIA typically to find these so I would see if there is a common feed point after the main light switch where all park circuits are fed from so you can separate front from back (for example) to try to isolate the problem as quickly as possible. Good luck.

[lwmcguir]

Start by disconnecting the burned out lamps and test with the socket unplugged

Work from there

[Beau388]

Generally Thor MC produces three separate wiring harness for the exterior lights. There is one for the front cap , one for the main body and one for the rear cap. The electrical connection for the caps are found on the left side lower portion of the cap and are usually just taped into position. Remember the trailer receptacle is part of the rear cap lighting harness. If you separate the plugs, it would narrow down your search for a short.

[csltbr@gmail.com]

Hi,Javelin,
I went out for a 10-day trip last month and now I remember I passed one area with some mud.
I opened the hood and noticed that wires for the driver side side is VERY LOOSE, so I tight it up, went under the car, noticed the connection was very dirty with a lot of dry mud, so I cleaned it up with a wet towel on all light connections.
After that, I do got my sidelights , tail lights back, I also got two smaller lights outside the front lights.
However one front light on each side(the stronger light) and one smaller light under the stronger light is still no working.
I check all fuses and they are all fine.
The lights that is not on shares the same input from the battery , I also checked the light bulks, that looks ok too.

Any suggestion at this stage?
Thanks again.

Originally Posted by javelin

Hi John, glad you confirmed the specific feeder fuse at least......and unfortunately also that you have a short circuit somewhere in your park/running lights system. I don’t have schematics for the F53 park light systems but I think after the 12vdc fuse feed passes through the main light switch (park on position) they go directly to the various park and running lamp locations. It would be nice to be able to isolate the lamp positions individually, but I am not sure where/if there is a common distribution tie point for the park wiring feeds near the main light switch. The short cct might even be something like a chafing body screw on the park wiring somewhere. Has there been any work done recently on or near any of the park or running light systems? If not, you might have to resort to removing lighting covers and inspecting the physical lamp socket connections for the short circuit. You don’t want to blow through a lot of expensive fuses so use your meter (or a 12vdc trouble lamp) to prove the short circuit to ground. It is a PIA typically to find these so I would see if there is a common feed point after the main light switch where all park circuits are fed from so you can separate front from back (for example) to try to isolate the problem as quickly as possible. Good luck.

[csltbr@gmail.com]

Please see my reply to Javelin, I did check all light bulbs and them seems to be OK and none of them are burned.
Thanks

Originally Posted by lwmcguir

Start by disconnecting the burned out lamps and test with the socket unplugged

Work from there

[csltbr@gmail.com]

Please see my reply to Javelin. Almost there!!!
Thanks

Originally Posted by Beau388

Generally Thor MC produces three separate wiring harness for the exterior lights. There is one for the front cap , one for the main body and one for the rear cap. The electrical connection for the caps are found on the left side lower portion of the cap and are usually just taped into position. Remember the trailer receptacle is part of the rear cap lighting harness. If you separate the plugs, it would narrow down your search for a short.

[javelin]

I am not familiar with your coach specific wiring details, but it sounds like in cleaning up the muddy driver side connections you somehow removed the short to ground on the park/running light circuit, since they are now working and fuse 6 is not blowing. (maybe there is a bad ground or bad multiple connection between headlights if that is how they are wired also?)
So it sounds like your headlights are still not working fully (only one on and the other is still off; the second smaller lamps are probably your high beams I assume?). If you tested the bad headlamp bulb continuity with your meter and it is OK, then you may have a bad ground connection or +12vdc at that headlight. The front headlights +12vdc feeds seem to be separate fuse feeds according to your 2016 chassis passenger compartment fuse panel (positions 25, 31); high beams are fed from fuse 35 according to the previous fuse record link I posted (it seems). You should also see a high beam lamp come on the dash when you flip the high beams on (multifunction switch on the steering column) since the dash lamp is probably fed from the same fuse (guessing). Again, I don’t know your coach specifics. So I would suggest testing for good ground and +12vdc on the headlight that is not working. Check the associated feeder fuses if you see no +12vdc at the bad headlight connector and also check +12vdc and ground connections at the high beam lamp connectors (when they should be in the “on” state). Good luck.

[csltbr@gmail.com]

The light bulbs are fine. For whatever reason I could not find the F53 Passenger Compartment Fuse Panel (which is Fuse 35 is suppose located). :
Any idea where could that be?

Originally Posted by javelin

I am not familiar with your coach specific wiring details, but it sounds like in cleaning up the muddy driver side connections you somehow removed the short to ground on the park/running light circuit, since they are now working and fuse 6 is not blowing. (maybe there is a bad ground or bad multiple connection between headlights if that is how they are wired also?)
So it sounds like your headlights are still not working fully (only one on and the other is still off; the second smaller lamps are probably your high beams I assume?). If you tested the bad headlamp bulb continuity with your meter and it is OK, then you may have a bad ground connection or +12vdc at that headlight. The front headlights +12vdc feeds seem to be separate fuse feeds according to your 2016 chassis passenger compartment fuse panel (positions 25, 31); high beams are fed from fuse 35 according to the previous fuse record link I posted (it seems). You should also see a high beam lamp come on the dash when you flip the high beams on (multifunction switch on the steering column) since the dash lamp is probably fed from the same fuse (guessing). Again, I don’t know your coach specifics. So I would suggest testing for good ground and +12vdc on the headlight that is not working. Check the associated feeder fuses if you see no +12vdc at the bad headlight connector and also check +12vdc and ground connections at the high beam lamp connectors (when they should be in the “on” state). Good luck.

[javelin]

Your headlight and high beam fuses should be located in the fuse panel near the driver's foot area. It is usually fairly awkward area to get to. Good luck.

[csltbr@gmail.com]

Unfortunately it looks like that fuse box is from Thor(please see attached pictures), not from Ford (see attached Ford fuse)...

Originally Posted by javelin

Your headlight and high beam fuses should be located in the fuse panel near the driver's foot area. It is usually fairly awkward area to get to. Good luck.

[Beau388]

Originally Posted by csltbr@gmail.com

Unfortunately it looks like that fuse box is from Thor(please see attached pictures), not from Ford (see attached Ford fuse)...

On my coach (also a product of Thor MC plant 750), the circuit board down the driver's left foot is for the interlock for the slides, step, jacks and the patio awning. Also there are the fuses for the defroster fans, map lights, jack control panel, heat and A/C power, mirror heat and movement, etc. Basically everything inside the front cap installed by plant 750. Power for this board comes from the chassis battery by the way of a 100 amp CB located on the frame rail just behind the battery.
Under the hood is Ford's high power fuse center. Power for the steering wheel controls comes from there, as does power for the dash's power ports. By the way the headlights are not fused. By DOT regs, they are protected by an automatic, fast reset CB. All other external lights are fused.

[javelin]

Well that’s no fun when things aren’t as we might expect! Clearly there is no Fomoco fuse panel beside the driver foot area in either of your coaches. My 2013 ACE has a passenger compartment fuse panel arrangement (by driver’s left foot wall area) that seems to follow my 2012 Ford stripped chassis fuse record more closely (from what I can tell without getting jammed in there to find out). Not only that, but the old ACE uses a BCC (Battery Control Center) which houses many of the fuses mentioned in Beau’s posting (like for steps etc). If I had to get in the fuse panel under the steering column/under dash, I would probably need the Fire Dept to come and extract me from that location. Sorry I can’t assist you further on this one John. Others with specific knowledge of your coach fusing will have to fill in the blanks that I can’t. I hope you find your trouble......might not even be fusing.

[csltbr@gmail.com]

Hi,Javelin,
You DID helped me a lot! at least most of it!
I really appreciated all your help.
No one know everything, especially it is not our profession.
I will post here when I found out the way to fix.
Thanks again.
John

Originally Posted by javelin

Well that’s no fun when things aren’t as we might expect! Clearly there is no Fomoco fuse panel beside the driver foot area in either of your coaches. My 2013 ACE has a passenger compartment fuse panel arrangement (by driver’s left foot wall area) that seems to follow my 2012 Ford stripped chassis fuse record more closely (from what I can tell without getting jammed in there to find out). Not only that, but the old ACE uses a BCC (Battery Control Center) which houses many of the fuses mentioned in Beau’s posting (like for steps etc). If I had to get in the fuse panel under the steering column/under dash, I would probably need the Fire Dept to come and extract me from that location. Sorry I can’t assist you further on this one John. Others with specific knowledge of your coach fusing will have to fill in the blanks that I can’t. I hope you find your trouble......might not even be fusing.