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Full Painless Harness and new headlights.

mr110

New Member
Joined
Aug 10, 2015
Messages
23
I just installed a full painless harness and new switches and i am wanting new headlights.

Do i need the nightlighter harness from wild horses if i am going with new LEDs or H4 bulbs?

Also does have one have a budget way to upgrade these lights. I see some reasonable prices but i know someone has pieced together THE best budget set up...saving a dollar for other accessories is always nice.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,345
No, with a new harness you don't have to have the relays, for most lamp setups.
But it can still be a good idea.

LED's use less current to work, but the relays stabilize the signal as well.
HID's the same.
H4's take the most current, so the system benefits the most from their use in the long term. Nothing wrong with using your wiring as-is without the relays, but the more you use the high beams, or the more powerful your bulbs (in case it's an off-road only rig and you don't care about legality or blinding oncoming drivers!) the more wear and tear the switch takes. The relays will help the next switch likely last the life of the vehicle!
You won't likely see any additional brightness, such as you would when adding them to the stock harness. Just less loading on the switch.

Basically then, you don't need the relays. They're just a nice bonus.

Paul
 

399strokerEB

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Wasilla, AK
I tried running h4's without the head light harness. After about 5 minutes the lights started flashing. Swapped out the headlight switch several times. Put the harness in and no more flashing lights.
 

DirtDonk

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Was it new wiring or the original stuff? Generally speaking, if you've got stock stuff that's what happens. Happened to me too after using the high-beams a few times. Not for long, and it first happened later when I was just driving around normally.
The first time the lights flipped off I was literally out in the middle of nowhere (well, for around here anyway, the road to Hollister was the middle of nowhere back then!) and the world went totally dark on me!
Talk about a rude surprise...

Anyway, never had that happen with new wiring and switches, but the good news is that after I added the relays, I'm still running that original switch from '71 without any trouble.

Paul
 

Glass Pony

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Feb 13, 2012
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Sussex County Delaware
I have a Painless harness running stock head lights and one day when I was at the DMV for inspection, I left the lights on for probably 50 minutes to an hour. When I stopped at the gas station on the way home I noticed the head lights turning off and on.
The Nightlighter harness fixed my issue.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,833
LEDs and HIDs have a driver that drives the bulbs. The part that actually makes the light does not run on 12V. These lights are known for having the same brightness if you give them 10V or 16V. They also draw less current (typically) than incandescent lighting.

Incandescent lighting varies output depending on the voltage applied. So if there is a voltage drop in the wiring, the light output will drop (but bulb life will go way up). This is where a relay harness can help. Bypass the stock wiring in delivering power to the bulbs. Relays also make the original wiring just a trigger wire and take the load off the headlight switch so the circuit breaker doesn't cycle. But it is not a fix for bad wiring or bad switches. A high beam switch that doesn't have good contacts still won't have good contacts even with relays. If there isn't power to trigger the relay, you still won't have light.

Relays also add a bunch of new failure points. Every terminal end, the contacts in the relay, the coil in the relay, all this stuff is new and added failure points. If there isn't a gain by adding them, why add them? At times they are needed, or at least a good idea to use. But they are not a cure all for everything. If the lights don't care if there is half a volt less getting to them, skip the complexity, cost, and added failure points.
 
OP
OP
M

mr110

New Member
Joined
Aug 10, 2015
Messages
23
I went ahead and snagged the TBP H4 kit, it was on sale. Comes with the harness. Figured it was a good first step.

Thanks for all the help.
 

Pa PITT

Contributor
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Jul 15, 2005
Messages
11,252
Loc.
Stephenville TEXAS
stroker What brand Head Light harness did you use.
I bought one of the harness from here on the Classic. When I got it I felt it had small wiring in it but yes it did have the harness.. It was easy to hook up .
So I hook it up & It ran about a year & Now my head light flash on & off just like they did before I ADDED THE relay harness.
.. I've considered pulling it out & Coping it &making one with14 gauge wire & New Relays .
Yes I have put in a couple of new Headlight switches & several new Dimmers .
 

DirtDonk

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47,345
But he just jinxed it with that simple statement!;);D

Paul
 
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