"Night Lighter" headlight relay wiring question

[Waverous]

I have an electrical gremlin I need help tracking down. I recently purchased a “Night Lighter” headlight harness from Wild Horses that I installed on my Bronco. Before installing the harness, I confirmed the headlights worked and switched between high and low beams. After installation, I tried the new setup and discovered I only had high beams. I researched the issue on CB and found a couple of suggestions that I tried out without success. I contacted WH, and they replaced my harness. I connected everything up with the new harness and tried the headlights again, and – no low beams again. An interesting observation is when I pull the headlight switch and try switching between high and low beams with the Night Lighter harness installed, I get low beams – click – high beams – click – high beams – click – high beams, and so on – low beams come on just once with the Night Lighter harness.

I have checked:

• Grounds
• Dimmer switch with a voltmeter
• Relays with a voltmeter and switching them out

Any ideas?


Thanks, in advance

 

[jerry]

Chris ( @Waverous )

If your dimmer switch is like mine, it will benefit from a few treatments of contact cleaner. Mine was sticky / operated intermittently...

Look for something that cleans and lubricates, like:

https://www.guitarcenter.com/CAIG/DeoxIT-D-Series-Contact-Cleaner-Rejuvenator-with-Adjustable-Low-Med-High-Straw-1500000376175.gc

This works well on other switches / rheostats / potentiometers, too.

You could rule out a relay by swapping them, but I feel like it's in your dimmer switch. Let us know!

Jerry

 

[jerry]

Another idea: swap the relays in their sockets to rule the slight chance of another bad relay.

I bought the WH kit 10+ years ago, and installed a few months ago. No problems, very straight forward.

 

[Waverous]

Another idea: swap the relays in their sockets to rule the slight chance of another bad relay.

I bought the WH kit 10+ years ago, and installed a few months ago. No problems, very straight forward.

I did try that - no luck.

 

[jerry]

Here's another thought:

Pull dimmer switch. Jumper the plug, see if both high and low beams work.

Here's a Ford truck diagram as an example:

https://www.ford-trucks.com/forums/attachment.php?attachmentid=139546&stc=1&d=1457213182

With headlight switch on: use test light or voltmeter to find hot lead.

Then, with suitable gauge wire, jump from that to each of the other two terminals.

If this works: sure feels like the dimmer switch.

While you're goofing, I'd also double check the connector to the headlight switch. When I did my painless install, one of the terminals pulled out of the socket.

Jerry

 

[Steve83]

...the headlights worked and switched between high and low beams.

...with the Night Lighter harness installed, I get low beams – click – high beams – click – high beams – click – high beams, and so on – low beams come on just once with the Night Lighter harness.

Maybe just return the harness, and keep using the stock system that works.

 

[Waverous]

Update
The issue has been resolved - I just rewired the harness, and now everything works fine.

 

[jerry]

Maybe just return the harness, and keep using the stock system that works.

True. Just assumed the odds of getting two "faulty" setups were slim... But clearly not none!

 

[Waverous]

After all the troubleshooting, I determined the issue wasn't the harness; the combination of the wiring harness I installed and some strange wiring gremlin that lives in the harness. Just to be clear, Wild Horses was great with their customer support - they exchanged my first harness and sent me a new one that was tested before shipping, so we knew it wasn't the harnesses. I decided to use some relays I had and rebuild the harness, removing one interesting piece included on the Night Lighter harness that neither Wild Horses nor myself could identify properly (picture below). I was also fixated on what I perceived as an issue with wiring into and out of the headlight socket - the wiring color didn't match across the socket connection - they were the same colors of wire in different positions on the socket. I've used mismatched wire colors when I wire something out of necessity or laziness, but I was sure Wild Horses didn't. so I switched them, knowing I would be sure of the current flow if I laid it out. So, with the rewiring and without that piece (switch/relay?) connecting the relays on my Bronco, I got the headlights to work properly.

If someone can tell me what this is, I would appreciate it.

 

[Slowleak]

It’s a diode.

https://www.amazon.com/dp/B0CPY19PW1/?tag=classicbroncos-20

 

[Waverous]

It’s a diode.

http://[URL]https://www.amazon.com/dp/B0CPY19PW1/?tag=classicbroncos-20

[/URL]

Thanks - now I know!