antipode

Yep, it only needs the one, and it's only using that to tell the relays to open/close. Your lights are powered from the battery via the relays.

Super simple installation, especially for me because I did mine when I was replacing my radiator. I'll have to pull it out again to re-crimp everything though, my high beams stopped working and my relays tested fine. Just check all the crimps before you install, but it's worth it because it's like - for lack of a better description - night and day.

Also, get spare relays! I keep a couple of these in the glove box. And yes, they're the right ones - it took me a bit of searching, but I've tested them and they're fine.

2dbatcv

Just did mine. Like everyone says, it's easy and worth it! I need to aim my headlights now because they actually put out enough light to see now. Awesome!

cruiser54

So they're now brighter than 2 candles flickering in the wind?

2dbatcv

Yes ha ha. I downloaded a light meter app and tested the light reflected off my garage door before and after. Went from 52 lux to 200 lux. Completely unscientific but does show they are much brighter than they used to be. I need to regroups the passenger side as its slightly dimmer but that can wait I think

cruiser54

A light meter app? Holy smokes.

2dbatcv

And by regroups I mean reground

cherokeelaredo'90

My passenger side headlight ia dimmer than my drivers too, but it was before so I believe the bulb is just corroded inside there or slowly dying.

Trombahonker

Hi there,

I know this is an old thread, but I wanted to chime in about the fuse sizing. It's important to size a fuse to protect the weakest part of a line, and in the case of this Putco wiring harness, it's the 16awg wire. The "safe" amperage for 16awg wire is 19amps, so the fuse must be less than 19amps. I chose to install individual in-line fast-blow 15amp fuses for both wires. Actually, a 20amp fuse is acceptable. I changed to two in-line ATM 20amp fuses.

A 100w headlight will draw 8.3amps at 12vdc, which is well within the 15amp fuse's capacity. BUT part of the wiring is carrying 16.6amps with 100w bulbs, so you need a 20amp fuse.

[EDIT: See my post below correcting to needing a 20amp fuse{

~A

carbuff

I didnt use the putco harness. I got a similar one off ebay that has the supply fuses already and uses real mechanical relays, not the small black ones that are prone to failure. It was priced the same. Its not yellow. Its been doing its job for 2 years.

Cherokee4LIF3

Is the reason you are installing the 15 amp fuse because you all a keeping the relays from being blown or the wire from being blown. Are you all cutting the main hot wire between the relays and the battery or before the relay. ie (--fuse--relay--battery or relay--fuse--battery) Are you using butt connectors to do the job. If so any jeopardy of connection integrity.

Trombahonker

Hi there,

The fuse is to protect the wiring. The harness as is connects directly to the battery, and also grounds directly to the frame. If these were normal incandescent bulbs and there were no relays, I'd be fine with no fuse (the bulbs would be the fuses). However, my concern is with all the wiring sitting out in front in all of these metal areas, and near some hot things. Some chafe, or perhaps an accident, and it'd be possible for that wiring to ground and melt down without ever going through the bulbs. Hence, 15amp fuses for both relays/sides.USE 20amp fuses. See post below. It cost about $6 dollars to add two in-line fuses, and I located them directly adjacent to the main fuse/relay box. I'll snap a photo and post it later.

~A

Trombahonker

You need a 20amp fuse if you're using 100w/80w bulbs.

I made a mistake and my 15amp fuse for the low beams was blowing. With 2x 100w bulbs, between the battery and the low-beam relay you have 200w @ 12vdc = 16.6amps of current. After the relay, it's split between the two lights, so the wiring is only carrying 8.3amps each. However, from the battery to the relay, you need a fuse that can handle the 16.6a of continuous current. A 20amp fuse is still adequate for protecting the 16awg wire.

This is also why the Putco 16awg wiring is limited to 100w. 130w bulbs would put 21amps through a part of the wiring - that's dangerously high for 16awg wires. DO NOT RUN 130w/90w bulbs with the Putco harness!