Awesome Hood Light Setup

Stoopid Jeep said:
That's I figured. Where/how did you tap into the parking brake circuit?
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It helps to first know how the parking brake circuit goes....basically the bulb's ground goes to 3 locations...the brake warning switch on the proportion/combo valve, then further upstream to the parking brake, and then to the ignition switch. The ignition switch grounds the circuit on start mode, the parking brake obviously when it's set, and the brake warning switch when you get air in the brakes.

so that circuit starts at the ignition switch, splices into two wires for a branch to go to the parking brake, and then the final leg goes out the firewall bulkhead connector, to the brake switch, and back into the cab through the bulkhead and to the instrument cluster.

So that brake warning switch comes out of the main large firewall loom that runs across the top from the battery to the bulkhead. I fished my wire through the big loom and over to the brake warning loom, and will splice it into the white/black wire there. You could splice it into the gray wire but then if you had air in the brakes you it would start to trigger your relay on the road.

Since it is the bulb you are grounding, technically the flow is from the bulb to the brake warning switch, through that switch, and then out to the other two. So the white/black wire is AFTER the brake warning switch. I will put the diode on the white/black wire with the stripe facing away from the brake warning switch just to make sure no feedback from my relay travels up that wire and messes with the bulb in the dash.

I had relays in the past on my truck tied to the brake and when I would set it, I would get weird flickering in the dash, so installing diodes has been my solution. I don't know if I will need it but I'm not going to wait to find out.

Here's a screenshot and some pics to make it make more sense. It's really quite simple. You can skip the diode most likely, I just choose to add it because I don't want to deal with any reworking again. I've edited this project enough.

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Stoopid Jeep said:
That's I figured. Where/how did you tap into the parking brake circuit?
Click to expand...
I hooked it up without the diode and did testing - works perfectly fine. No need for diode. At least not with the relay I'm using which is a Fastronix brand Bosch style 5 pin. Fastronix has always worked well for me. When I've needed diodes I was using other brand relays so YMMV.

so assuming same luck as me, run your relay ground over through the firewall loom and splice it into the white/black wire going to the brake fluid pressure switch on the proportion valve. You'll be good to go after that.
 
Nice CLEAN
machoheadgames said:
Figured I’d update this thread. Originally I was going to install this hood light setup and wire the power to power and the ground to a hood pin switch. the plan was to pull the ground wire if I needed to shut off the light a while. I did do that, and didn’t like the way it turned out. The switch was inconsistent and didn’t always spring all the way up, causing intermittent problems.

Haven’t been working on the Jeep much lately so I didn’t do anything to fix it until now. I wanted to improve my install any amount I could. I started at the lights and figured out how I’d get the wiring routed and such. I ordered some stainless loom clamps (bolt style) and bolted the loom down to the bolt holding the aluminum lights support bracket.

View attachment 119317

There is a 1/4” hole about 2/3 the way down the hood, which I fastened a stock style “rosebud clip” loom clamp to. I secured the loom at that end.

There was a hole in the hood channel right below the rosebud clip hole. I downsized the loom so it would fit and then fished it down to the hole at the very bottom of the hood (where the loom comes out).

So that gets the wiring from the lights secured and ran down to a part of the hood where I can work on it.

Next, I had to plan how I wanted the the lights to actuate. Since I was no longer using the spring loaded switch, I needed an alternate solution. The YJ factory hood lamp being removed leaves a hole to bolt to and an indexing slot to keep the light from rotating. I learned the factory TJ/JK/JL hood light will bolt right up. So I ordered one.

The TJ hood switch comes with a bulb inside, which I removed. The contacts were bent to hook to the bulb. I straightened them out and put female terminals on them. This isn’t my picture but is the same concept. I drilled a hole in the non-connector end (top in this pic) and ran my two output wires out the tilt switch housing.

View attachment 119318

The TJ switch has a backer plate which bolts up to the hood and then the TJ switch clips to it. The backer plate bolts down with a self tapper style of bolt. I used a random screw I had on hand.

View attachment 119319

I wired the pigtail for the TJ switch up to the stock YJ hood light wiring. I hooked up the KC lights to the output but the results were too jittery. The tilt switch isn’t really ideal for supporting draw from the lights. If you tap the hood at all you get lots of flickering. So back to the drawing board….I needed a relay.

I got a relay from Fastronix and fastened it to one of the hood tie-down nuts. Bolted up perfectly.

View attachment 119320

What I ended up doing was wired the factory wiring to the TJ switch and split the ground to the lights as well. The outputs of the TJ switch go to the relay to trigger it. Power comes through the TJ switch and powers the circuit that feeds the KC circuit from the relay.

The basic operation is that tilting the hood up allows the TJ switch to trigger the relay, which powers the lamps. The switch is still finicky but instead of flickering lights, I get a relay going on and off but it takes more effort to kill the relay activation than it did to make the lights flicker. So it’s a win.

The light output is great and functions well.

View attachment 119321View attachment 119322

And here’s a video of it in action. Works well.

View attachment 119323


BUT WAIT, THERE’S MORE!

That switch is going to trip when I’m driving. I don’t want the hood light to come on when I’m going down the road, so I’m redoing the ground side. The ground currently grounds the lights and also goes through the switch to ground the relay. The relay/switch side I’m going to ground to the parking brake circuit instead. This way when I’m driving, the light can’t come on. Then when the Jeep is sitting and the parking brake is set, that will allow the circuit to ground (but still only when hood is lifted). So this will prevent the lights coming on when going down the road.

I am currently waiting on some heat shrink to arrive and then I will finish it up. Overall this project finally turned out great and the wiring is really clean. I wasn’t sure I’d be able to get it that clean.
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Nice CKEAN install...Mikey Likey!!!
The uninitiated would never know it wasn't factory!
 
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jeepjoe43 said:
Nice CLEAN

Nice CKEAN install...Mikey Likey!!!
The uninitiated would never know it wasn't factory!
Click to expand...
Thanks! It was a decent bit of work but the best way I could come up with the achieve everything I wanted out of it.

Now here I am dissecting an entire hardtop harness to remove a relay and one really long wire to add a defrost feature to my hardtop that I might not ever use! :ROFLMAO: The activities never end.
 
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