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Discussion Starter #1
By this point, I think everyone is aware of the pulse wave modulation Jeep was so kind to have utilized in their lighting system design. Run the power through the computer to the lights, not like a circuit with direct battery feed works or anything so why not. The result being that you get a flicker when you run LED’s, slight pulsation in the stock lights, and no ability to run a relay off that system without isolation. There are several companies that make aftermarket harnesses to take care of the problem. As with everything, some are better than others. Some companies will sell you an $800 set of lights & not address the issue so you get a flicker.

HERE is my solution that, unlike an aftermarket harness, allows for unlimited expandability of the lighting control circuits. Total cost of the system - $35. I have extra parts & the harnesses look factory. Not to mention that the ENTIRE THING can be removed with no trace of the mod (except for the mount locations since I had to attach somehow).

The idea is to create two source locations with constant 12-volt supply that are controlled by the high and low beam circuits both separately and in conjunction with each other. These locations can be used to supply any device you choose from LED’s to miscellaneous interior mods of your choice that you want to come on with the lights.

Here is the circuit diagram.

Schematic 2.jpg
Here are the parts –

HARNESS.jpg

headlight extension harness ($7 for a pair),

Capacitors.jpg

Capacitors ($7 for a pair),

Relays1.jpg

5 pack of 5 wire relays with manufactured harnesses ($15) & some wire.

Cut the yellow plugs off the capacitors. Tie them to harness blue & red wires. You will plug in the blue connector to the yellow connector "upstream" of the capacitors. The cut lines on the capacitor are wired to the relays as controller circuits. Battery power (12 gage wire) split to the two HOT inputs to the relays. Low relay out to device. High relay out to low relay aux power in (Optional).

The net result is as follows:

Complete shot 1.jpg

Turn on low beams, high capacitor is off, the low capacitor is energized, the low relay closed circuit is activated & direct power from the battery is allowed to flow through the low relay direct circuit & out to the device.

Turn on high beams, low capacitor is off, the high capacitor is energized, the high relay closed circuit is activated & direct power from the battery is allowed to flow through the high relay (optionally to the low relay open circuit allowing the device to operate basically uninterrupted under either high or low conditions as in the diagram) & out to the device.

You now have 2 constant 12V hubs controlled by the factory column switches. You can now route that power to any device you choose (even back to the stock lights) with as many relayed circuits as you want without taxing the stock lighting circuit by more than a few mili-amps to close the high & low relays. All power to the device(s) is directly from the battery – no more PWM, no high dollar harness that can only be used with a single set of lights, no more banks of capacitors for every set of aftermarket lights, no SPOD. All DIY with bragging rights.
 

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Discussion Starter #2
And to the Engineers at Chrysler that caused the problem in the first place, Marvin has a message for you







Marvin.jpg
 

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I used a pulse-wave modulater once, but it set downtown Chicago on fire, and was deemed a "terrorist" tool. Bummer. :)
 

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Pretty cool!

The only downside being if your ECU goes bad and Jeep sees that DIY wire concoction you can be sure they'll figure out a way to link the two.
 

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It's not like Chrysler hasn't been doing strange and useless crap to their electrical systems for DECADES. Resistive door lock triggers, reversed polarity door pins. Nothing surprises me any more.
 

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As an Electronics Engineer I have to seriously ask WTF were they thinking? If they wanted the PCU to control everything in the vehicle, there are easier ways to do it, that generate less issues, utilize less manufacturing resources and get this... LEAVE ROOM FOR MORE (gasp) PROFIT... and this nonsense started before Obama became a member of the board of directors...
 

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Discussion Starter #11
Pretty cool!

The only downside being if your ECU goes bad and Jeep sees that DIY wire concoction you can be sure they'll figure out a way to link the two.
That's the beauty of the whole setup
The high & low connections are made to the new harness inserted between the factory headlight connector and bulb without splicing into the factory wires.
The battery feeds come from a single connection to the pinch nut / clip / bracket on the positive terminal.
The capacitors and relays are screwed to the plastic hump behind the washer fluid reservoir with self tapping screws & the hole filed flat so no plastic screw debris visible even after the parts are removed, just the small holes whose use would be indeterminate.

All completely removable in less than 5 minutes without evidence - except the small holes. Do what you will with your device.

As to the physics, the factory circuits never see the higher amperage associated with the device since it is relayed from the battery. With the 5 wire relay, the two positives never meet so there is no difference in potential within the relay circuit. I was initially concerned about the lag time when flashing between high & low circuits but that does not appear to affect the device.

Capacitor failure? Well, that's what fuses are for. I do not foresee a scenario when the capacitors cause a voltage spike with failure that would cause large amounts of current travel "backwards" for lack of a better term. But then again, I am a CE not a EE.

Nectoxicdragon, being a EE, can you confirm the typical failure mechanism of DC capacitors under a pulsed wave condition? Pop & you're done? Failure between the plates & ground? Or am I completely off base & they allow charge to massively accumulate & voltage to spike prior to the pop?
 

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Discussion Starter #12
I used a pulse-wave modulater once, but it set downtown Chicago on fire, and was deemed a "terrorist" tool. Bummer. :)
I assume your modulator was confiscated by that hero of the DHS - Stooperduck?

I thought the Chicago fire was back in the 19th Century? Now I know your knowledge is experience based. :whistling:

Kidding KB
 

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That's the beauty of the whole setup
The high & low connections are made to the new harness inserted between the factory headlight connector and bulb without splicing into the factory wires.
The battery feeds come from a single connection to the pinch nut / clip / bracket on the positive terminal.
The capacitors and relays are screwed to the plastic hump behind the washer fluid reservoir with self tapping screws & the hole filed flat so no plastic screw debris visible even after the parts are removed, just the small holes whose use would be indeterminate.

All completely removable in less than 5 minutes without evidence - except the small holes. Do what you will with your device.

As to the physics, the factory circuits never see the higher amperage associated with the device since it is relayed from the battery. With the 5 wire relay, the two positives never meet so there is no difference in potential within the relay circuit. I was initially concerned about the lag time when flashing between high & low circuits but that does not appear to affect the device.

Capacitor failure? Well, that's what fuses are for. I do not foresee a scenario when the capacitors cause a voltage spike with failure that would cause large amounts of current travel "backwards" for lack of a better term. But then again, I am a CE not a EE.

Nectoxicdragon, being a EE, can you confirm the typical failure mechanism of DC capacitors under a pulsed wave condition? Pop & you're done? Failure between the plates & ground? Or am I completely off base & they allow charge to massively accumulate & voltage to spike prior to the pop?

OOooooh, I like reversible. :thumb:
 

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Discussion Starter #15
OOooooh, I like reversible. :thumb:
110% agreed.

That's my thought process regarding my 2" Rancho lift that's going on this weekend. :thumb:

Easily removable if I have a drive train issue & have to go in for warantee work.

That's why I am keeping my factory 18" wheels too.

My guy at the dealer left & the new guy is kind of... well... Let's just say I do not want to have that conversation.
 

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Discussion Starter #16
LOL. Good idea.

I was thinking about building a "Black Box" type of thing out of PVC but the dimensions were working out to be too large for a practical installation that would not look like crap. I came up with 6 x 9 x 2 without the width of the plastic.

I may still do a cover of some sort but as with every Jeep mod, it's a work in progress.
 

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Discussion Starter #17
There HAVE TO BE more comments out there if a low rider thread gets 26 responses.

Any more feedback?

You guys' opinions are always interesting - even the uninteresting ones :D
 

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What about the flux capacitor? Does it still need 1.21 jiggawatts?

But seriously it sounds great I just wish u lived close to me so u could come and do mine. When it comes to electrical stuff I stay away I know my limits even if it's really simple.
 
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