brake/signals work, but no tail lights or side lights

chrisarrick

Member
Oct 10, 2017
77
North Central Indiana
Hi all, This past weekend I was able to get out for a night in my new to me 84 jayco 1008. Last fall all of my lights worked fine. But now, all I have are brake lights and turn signals in the rear. So, I can travel during the day but never at night. I have checked, re-checked and triple checked that the wiring was the same at the harness as last fall and have searched here and the web for jayco wiring and it really does seem I have it correct. A rodent chewing wires in the camper is most suspect, of course.
I have no idea where to start looking next. I am in no way very handy with electrics, very basic skills, but it seems I have voltage where I need it, I have a good ground. Is there a good first place to start checking and how do I test for continuity if needed?
Another question, and I hope it's not a dumb one, but I'll ask anyway... Are these lights like Christmas tree lights? Meaning if bulbs are out will they all be out?
Thank you much for insight!!
Chris
 

eoleson1

Super Active Member
Jul 5, 2011
3,613
Macomb County Michigan
I'll answer your last question first: No. They are wired in parallel, so if one goes out, the rest will continue to work.

To diagnose your issue, I would start by checking the tow vehicle (TV) wiring. Make sure you have 12V on the brown wire when the running lights are on. If you do, then move on to the trailer. Check for 12V at each of the light sockets with the TV connected to the trailer and the running lights on. Verify that you have continuity to ground between the TV and the trailer, and from the sockets to the trailer.
 

roybraddy

Super Active Member
Mar 23, 2016
2,393
King George, Virginia
X2 of starting at the source which is the truck 7-way receptacle.

I use one of these 7-way circuit tester (AMAZON) and if all of the small LEDs work normally using this unit plugged into the 7-way receptacle then your trailer brakes and lights are normal leaving your truck. Knowing you are good at the truck 7-way receptacle speeds up things finding your DOT Safety Light problem.

AHdZgCH.jpg

Google image

The 4-way TEST module looks like this

BlmHLwb.jpg

Google image

Keep in mind none the DOT SAFETY LIGHTS are fed by anything on your trailer side.
The 12VDc DC required for the SAFETY lights are all powered by the truck side 12VDc Start battery... I think all of my circuits are protected by a ATC fuse in one of my truck three fuse panels. Check your truck manual for this info.

The only minor problems I have sometimes with the DOT Safety lights being intermittent are due to dirt or grim inside the truck receptacle. Since I always seem to have a can of WD40 and some DUCT TAPE in my truck door storage I usually spray a little WD40 into the truck 7-way connector and wiggle it all around when connecting up to the trailer... This cleans the actual connections somewhat. A better thing to use would be to clean the connections with something called Dielectric Grease...

A good place to look at typical wiring diagrams of the DOT Brake and light wiring is ETRAILER.com on the internet... For me they are main go to internet source for everything trailer... Lots of great info on their site and a also a great source for trailer lights etc...

Also note a loose ground connection between the truck and trailer really does strange things to the DOT Safety Lights operations...

Roy Ken
SoQ6BfGm.jpg
 

chrisarrick

Member
Oct 10, 2017
77
North Central Indiana
I have power from the trucks receptacle but not at the end of the harness that plugs into trailer frame female socket (for tail lights). I try to jumper those & still don’t have tail lights. A white ground wire turns into a black ground wire. The yellow wire on the male side trailer harness is snipped (came that way) but I have a yellow wire that connects to white wire at each tail light. what the absolute hell is going on??!! These are factory connections, mind you. etrailer site says that the yellow & Black wires are not determined or used for something else. As far as I can tell there is no wiring for reverse.
 

chrisarrick

Member
Oct 10, 2017
77
North Central Indiana
What I found online for Jayco wiring:
Green-tail lights
White-ground
Red-left turn & brake
Brown-right turn & brake

So in my case if I connect ground to ground and brown (truck harness) to green (camper harness) I should have tail lights.

I assume the side lamps turn on with head/tail lights. At least they did last fall.
 

Katskamper

Super Active Member
Nov 21, 2015
872
Fort Worth, TX
X2 of starting at the source which is the truck 7-way receptacle.

I use one of these 7-way circuit tester (AMAZON) and if all of the small LEDs work normally using this unit plugged into the 7-way receptacle then your trailer brakes and lights are normal leaving your truck. Knowing you are good at the truck 7-way receptacle speeds up things finding your DOT Safety Light problem.

AHdZgCH.jpg

Google image

The 4-way TEST module looks like this

BlmHLwb.jpg

Google image

Keep in mind none the DOT SAFETY LIGHTS are fed by anything on your trailer side.
The 12VDc DC required for the SAFETY lights are all powered by the truck side 12VDc Start battery... I think all of my circuits are protected by a ATC fuse in one of my truck three fuse panels. Check your truck manual for this info.

The only minor problems I have sometimes with the DOT Safety lights being intermittent are due to dirt or grim inside the truck receptacle. Since I always seem to have a can of WD40 and some DUCT TAPE in my truck door storage I usually spray a little WD40 into the truck 7-way connector and wiggle it all around when connecting up to the trailer... This cleans the actual connections somewhat. A better thing to use would be to clean the connections with something called Dielectric Grease...

A good place to look at typical wiring diagrams of the DOT Brake and light wiring is ETRAILER.com on the internet... For me they are main go to internet source for everything trailer... Lots of great info on their site and a also a great source for trailer lights etc...

Also note a loose ground connection between the truck and trailer really does strange things to the DOT Safety Lights operations...

Roy Ken
SoQ6BfGm.jpg

is there any tool you dont own? you always provide informative answers& instructions!
 
  • Like
Reactions: jnc

chrisarrick

Member
Oct 10, 2017
77
North Central Indiana
Again, thanks to all for info/help. I know this is an old thread now, but other work around the farm keeps getting in the way of the fun things I want to do!
I have finally solved the problem, there were 2 problems actually. A problem with the jayco wiring harness connector in the trailer tongue and a bad/rusty ground. I bypassed the square connector in the tongue and ran jumpers from the 4 pin and I got tail lights, side markers, brake lights and signals. I even got them all at once! Haha! Thanks all!
 

jnc

Welcome from New Hampshire
Oct 1, 2014
3,933
South Central New Hampshire
Again, thanks to all for info/help. I know this is an old thread now, but other work around the farm keeps getting in the way of the fun things I want to do!
I have finally solved the problem, there were 2 problems actually. A problem with the jayco wiring harness connector in the trailer tongue and a bad/rusty ground. I bypassed the square connector in the tongue and ran jumpers from the 4 pin and I got tail lights, side markers, brake lights and signals. I even got them all at once! Haha! Thanks all!
We have a Winner.[:D]
 




Top