One Ditch Light Not Working...

I recently installed a secondary aux fuse panel in order to clean up my rats nest under the hood a bit. Upon installation everything worked, checked all accessories plugged into it and everything worked like a charm. Problems started to arise when I got off road... at night... I noticed both ditch lights started to flicker a bit and about a half a mile down the road my passenger side ditch light completely went out (farthest from the battery).

This is how it is set up:
Fuse panel:
Battery to fuse panel -> fuse panel has 20 amp fuse to harness

Harness:
panel to relay (I can hear relay turn on when pushing switch so i know that not the problem...)
relay -> switch
relay -> driver's side ditch light (working)
relay -> passenger side ditch light (not working)


Cant quite figure out what the problem is... What I've tried:

• changing the fuse (multiple amps 5,10,15,20..)
• redoing all the connections
• taking off/cleaning/reconnecting the relay
• taking off/cleaning/reconnecting the plug to the malfunctioning light

This same harness came with a 15amp inline fuse wired directly to the battery (originally had a 15amp fuse in panel but changed it to 20 incase the second light wasn't getting enough...). Inline fuse version directly to batter worked fine for years so I'm assuming something is going with the fuse panel but I cant be sure.

In this photo I haven't heat shrunk things yet because I was still trouble shooting...

 

Bump...

 

Best thing to do is round up a multimeter and check voltage at every point you can access, starting at the battery and working toward the failed light. Otherwise you're just guessing.

 

I just did this... still not sure why it’s not working...

Getting 12.9v from the battery
12.5 from fuse panel
12.3from wires connected to fuse panel from harness
12.1-12.5 from both the connections from the harness to the lights...

Still just getting the one light lighting up...

I’m thinking the male connector might be bad on the passenger side light but that still doesn’t explain the flickering that both lights were/are having.

 

Hm. do you have a schematic or drawing of the circuit?

 

Let me work one up real quick... one moment lol

 

Here you go

 

Hm. I'd look at switching the lights or powering them from another source individually to make sure they're both working right.

How are they grounded? That drawing shows the black wire going back to the relay, which is weird. A loose ground could be the problem with the flickering on both.

 

They are grounded to the fuse panel from the relay... then panel to ground on the side of the engine bay which I used as a ground prior for a couple years.

This is the original harness if that helps, i just cut out the inline fuse and wired the connection from there since I would be having the fuse be in the fuse panel instead...
https://caliraisedoffroad.com/collections/wire-harnesses-splitters-relays/products/wiring-harness

 

Have you considered the possibility that one light may have gone bad?

 

I have considered it... I'm going to pull the light off and try it on the other connection on the drivers side after work. If that doesnt work then I am going to try pulling the male connector off and test the light without the connector on it. and if that doesnt work than I know for sure the light is done

I'll keep yall updated haha

 

The only reason why I don't think it is those things is because they were working totally fine for years and then 3 days after I switched to the aux fuse panel they went out.

 

Using a test light or DVM, follow the power and the ground paths.

 

Sorry I'm a newb.... DVM?

 

DVM=Digital Volt Meter. A simple Test Light might be easier to use.

 

Ah gotcha - I took a multimeter to all the connections earlier on my lunch ^^

 

So you have power. Do you have ground?

 

The ground goes back into relay with the harness I have. then relay to ground goes to the fuse panel

 

But do you have good grounds for both lights and the relay? Sounds like all of your grounds are tied together.

 

Quick and easy disconnect the light and just have the wires touched to some temp wires to the battery. If it doesn't light up, you know its a bad light.