Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 

Go Back   Keystone RV Forums > Keystone Tech Forums > Repairs & Maintenance
Click Here to Login

Reply
 
Thread Tools Display Modes
 
Old 11-18-2021, 07:08 AM   #1
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
Figuring out why running light fuse keeps blowing

For several months (over a year?) I have had issues with the running lights first flickering, then the fuse in the tow vehicle would blow and no running lights. As long as I travel in the day, not a legal issue but it is a safety issue.

This weekend we head to CA for the Thanksgiving holiday and I may be towing at night so I need to get to the bottom of things. Both for safety and legality.

I know, I know, procrastination waiting to the last minute blah blah blah. No need to go down that path.

While diagnosing last night. I noticed that the front right ground level running light was warm too warm for an LED on a 28 degree evening. I pulled the fixture, looked behind and found at least part of the problem.

Click image for larger version

Name:	Photo Nov 18, 6 47 31 AM.jpg
Views:	97
Size:	127.1 KB
ID:	37143

So hot that over time that the insulation actually melted.

If you are having issues with running lights, check each fixture! Physically remove the fixture and look at the wiring behind!

I repaired what I could of the circuit. removing this mess. But now the front (top and ground level) running lights don't work. The midship and rear running lights are working and NOT flickering or blowing the fuse in the tow vehicle. A bit safer but I would like to get the remaining lights functional.

I need to trace the circuit from that front right ground level fixture and find the break.

I hate spark chasing.

Plan of attack:
Remove existing fixtures that are not working.
Inspect wiring behind
I know these are wired in series.
Temporarily tie white to white green and check for continuity from fixture to fixture. If I find a break or loss of continuity, replace the wire n that run (easier said than done).

Hopefully that addresses the issue.

Any advice or pointers on chasing this down?
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Old 11-18-2021, 07:17 AM   #2
ChuckS
Senior Member
 
ChuckS's Avatar
 
Join Date: Mar 2014
Location: Mountain Home, Idaho
Posts: 2,977
Good find with the first light fixture... Also the running lights are WIRED IN PARALLEL... if they were wired in series the voltage drop from light to light would cause each light wired after the first one to progressively be dimmer and dimmer and dimmer
__________________


2007 GMC Classic club cab 4x4 Duramax LBZ
2014 Alpine 3010 RE. 34 foot fifth wheel
ChuckS is offline   Reply With Quote
Old 11-18-2021, 08:54 AM   #3
LHaven
Senior Member
 
LHaven's Avatar
 
Join Date: Feb 2019
Location: Wickenburg
Posts: 3,271
If I understand your narrative correctly, all the lamps were working but would blow the truck fuse... you scrapped out and replaced melted wiring behind one fixture, and everything came back solid except two fixtures now solidly off, nearby the fixture you replaced (significant if true). If so, I'd take that fixture back off and fish around behind it for a lead you may have lost inside the wall when you were performing your replacement. The fact that those lights were lighting before your repair is the big indicator here.
__________________
2019 Cougar 26RBSWE
2019 Ford F-250
LHaven is offline   Reply With Quote
Old 11-18-2021, 09:52 AM   #4
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
Ok, so will my tactic of "Temporarily tie white to white green and check for continuity from fixture to fixture" work?

Do I need a different approach?
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Old 11-18-2021, 09:54 AM   #5
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
Quote:
Originally Posted by LHaven View Post
If I understand your narrative correctly, all the lamps were working but would blow the truck fuse... you scrapped out and replaced melted wiring behind one fixture, and everything came back solid except two fixtures now solidly off, nearby the fixture you replaced (significant if true). If so, I'd take that fixture back off and fish around behind it for a lead you may have lost inside the wall when you were performing your replacement. The fact that those lights were lighting before your repair is the big indicator here.
I tied in all of the wires I may have a bad splice though due to a tricky location inside the driver's side propane compartment.
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Old 11-18-2021, 10:06 AM   #6
LHaven
Senior Member
 
LHaven's Avatar
 
Join Date: Feb 2019
Location: Wickenburg
Posts: 3,271
If my memory is correct of what the color coding on Keystone wires means, tying write (ground) to white-green (+12V) is just going to create a short from power to frame. I don't know whether you planned to apply power in this configuration or not, but either way, I can't imagine how it would help you trace a lost power lead to ground out all the other lights' power lead (and blow another truck fuse).

EDIT: (the ad service has begun crashing my webpages before I can finish typing stuff...)

If it were me, using the tools I have on hand, I'd grab my telephone "toner," apply tone to the +12v contact on one of the problem lights, and verify it shows up at the other problem light… then I would try locating (through the wall) the "leaky" end of the cable in the vicinity of where I did the rewiring work.
__________________
2019 Cougar 26RBSWE
2019 Ford F-250
LHaven is offline   Reply With Quote
Old 11-18-2021, 12:09 PM   #7
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
Unfortunately, I don't have a toner tool anymore. Mine broke and I don't cabling or line work anymore.

I was not applying power, just checking for continuity along that pair of lines.
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Old 11-18-2021, 12:11 PM   #8
JRTJH
Site Team
 
JRTJH's Avatar
 
Join Date: Mar 2011
Location: Gaylord
Posts: 26,841
If the running lights are all LED's, you "may have inadvertently" crossed wires and connected the +/- leads for that row of lights backwards. Not suggesting you did, but worth a check to see....
__________________
John



2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS
JRTJH is offline   Reply With Quote
Old 11-18-2021, 01:10 PM   #9
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
Quote:
Originally Posted by JRTJH View Post
If the running lights are all LED's, you "may have inadvertently" crossed wires and connected the +/- leads for that row of lights backwards. Not suggesting you did, but worth a check to see....
Maybe the easiest fix, at least easiest to check...

Thanks
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Old 11-18-2021, 02:24 PM   #10
LHaven
Senior Member
 
LHaven's Avatar
 
Join Date: Feb 2019
Location: Wickenburg
Posts: 3,271
I could see checking for continuity on the white-green between lamps (although I would suspect you already know you don't have it on the dead ones). But I don't see how adding the frame ground to the mix improves anything. It seems to me it would just muddy the results by potentially introducing spurious continuities. Maybe I just don't understand what you're trying to test.
__________________
2019 Cougar 26RBSWE
2019 Ford F-250
LHaven is offline   Reply With Quote
Old 11-18-2021, 05:42 PM   #11
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
ok, figured it out.

First I'm an idiot! In my haste to get things patched at the storage yard last night, I actually cut the wires that feed the front running lights. Fixed that and the top cap running lights came on along with the Driver's side lower front the curb side lower front was still not coming on.

I hand traced the wire that goes across the trailer just above the front storage compartment between the lower front running lights and found the real problem with the flickering lights and eventual blown fuse.

Click image for larger version

Name:	Photo Nov 18, 6 21 16 PM.jpg
Views:	94
Size:	194.0 KB
ID:	37148

The break was on the curb side just before it runs into the propane storage cabinet.

I ran new wiring across the front storage bay. All lights working!!

FWIW the front lower running lights are in fact wired series. I suspect some sets of the lights are series and others are parallel.

Glad this is solved

Thanks for chiming in.
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Old 11-18-2021, 05:48 PM   #12
JRTJH
Site Team
 
JRTJH's Avatar
 
Join Date: Mar 2011
Location: Gaylord
Posts: 26,841
Sparking wires just behind the propane storage cabinet, and now, potentially compounded by a propane regulator recall... YIKES !!!

Glad you got it fixed before your trip. Enjoy your travels !!!!!
__________________
John



2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS
JRTJH is offline   Reply With Quote
Old 11-18-2021, 06:03 PM   #13
LHaven
Senior Member
 
LHaven's Avatar
 
Join Date: Feb 2019
Location: Wickenburg
Posts: 3,271
So you had two entirely independent hot spots on the same circuit?
Brrrr!
__________________
2019 Cougar 26RBSWE
2019 Ford F-250
LHaven is offline   Reply With Quote
Old 11-19-2021, 02:26 AM   #14
ChuckS
Senior Member
 
ChuckS's Avatar
 
Join Date: Mar 2014
Location: Mountain Home, Idaho
Posts: 2,977
If those running lights are wired in series... which they wouldn't be OEM then you WILL have a voltage drop across each light and each light would be dimmer than the first... just saying.....
__________________


2007 GMC Classic club cab 4x4 Duramax LBZ
2014 Alpine 3010 RE. 34 foot fifth wheel
ChuckS is offline   Reply With Quote
Old 11-19-2021, 11:14 AM   #15
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
well, series may not be right word but he lower front driver's side running light has three sets of wires.
1 set supply wires coming in from the kingpin.
1 set for the actual light fixture
last set goes across the front of the trailer to the curbside running light.
This was definitely the factory wiring. I'm the first owner and this is the first time I have done anything with the wiring for the running lights.
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Old 11-19-2021, 02:21 PM   #16
flybouy
Site Team
 
Join Date: Oct 2011
Location: Joppa, MD
Posts: 11,714
Quote:
Originally Posted by KimNTerry View Post
well, series may not be right word but he lower front driver's side running light has three sets of wires.
1 set supply wires coming in from the kingpin.
1 set for the actual light fixture
last set goes across the front of the trailer to the curbside running light.
This was definitely the factory wiring. I'm the first owner and this is the first time I have done anything with the wiring for the running lights.
If it were in series then the light would have a positive wire running thru the light to the next light and the last light in the circuit would have a positive wire going in and the other dide of the light grounded. In a parallel circuit , each ligh fixture will have a positive connection on one side and a ground connection on the other side of each light fixture.
__________________
Marshall
2012 Laredo 303 TG
2010 F250 LT Super Cab, long bed, 4X4, 6.4 Turbo Diesel
flybouy is online now   Reply With Quote
Old 11-19-2021, 02:25 PM   #17
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
I just copied the pattern with fresh wire that won't get pinched. Lights are working. Hopefully the fuse won't bow anymore. I'll know more tomorrow
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Old 11-19-2021, 02:40 PM   #18
flybouy
Site Team
 
Join Date: Oct 2011
Location: Joppa, MD
Posts: 11,714
Quote:
Originally Posted by KimNTerry View Post
I just copied the pattern with fresh wire that won't get pinched. Lights are working. Hopefully the fuse won't bow anymore. I'll know more tomorrow
Hope you found it. There's nothing more aggregating than an intermittent problem. We had a Keystone Cabana years ago that would blow the clearebce light fuse periodically. Took me 2 years to finally find the grounded wire after continually searching for it.
__________________
Marshall
2012 Laredo 303 TG
2010 F250 LT Super Cab, long bed, 4X4, 6.4 Turbo Diesel
flybouy is online now   Reply With Quote
Old 11-19-2021, 04:17 PM   #19
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
It has been more than a year. The requirement of driving at night forced my hand into deeper investigation.

I'll report either during or after the trip.
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Old 11-21-2021, 04:59 PM   #20
KimNTerry
Senior Member
 
Join Date: Jul 2015
Location: Windsor
Posts: 236
Made it to CA safe and sound. Lights worked great not a single flicker.
__________________

2016 Cougar 1/2 Ton Series 283 RETWE
2018 F150 EcoBoost FX4 Lariat Max-Tow and Heavy Duty Payload Package
KimNTerry is offline   Reply With Quote
Reply

Tags
fuse, light

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by the Keystone RV Company or any of its affiliates in any way. Keystone RV® is a registered trademark of the Keystone RV Company.


All times are GMT -8. The time now is 11:27 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.