LED Conversion not powering up?? - Page 2 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > LED Conversion not powering up??

Ring & Pinion's, Lockers, 4340 Axles, Install Kits, BaRockridge 4WD IS Taking Zone Offroad Suspension Lift Kits Engo winches available at www.rockridge4wd.com! Free shipp

Reply
Unread 03-24-2012, 09:28 PM   #16
341012
Registered User
 
Join Date: Sep 2011
Posts: 111
Quote:
Originally Posted by dusterdude
I admire your persistance,but this is an awful lot of trouble considering this is a jeep and not a hoopdie

Problem is its:
figure it out and have the experience and knowledge
OR
go back, and waste time effort money already spent, plus buy new tail assemblies and go get some replacement pigtails from the junkyard and change it all back.

I learn through experience and have basic knowledge I'm trying to expand.

I feel like Im so close... and if I don't get it fixed soon I might change it back, but damnit I'm determined to make it work cuz it looks so effin good!

341012 is offline   Reply With Quote
Unread 03-27-2012, 12:58 PM   #17
341012
Registered User
 
Join Date: Sep 2011
Posts: 111
http://www.youtube.com/watch?v=ty47L...ature=youtu.be

Well here's the link from them working for 2 days, I've tried a few more things, but i'm just not knowledgable enough to make these work. Maybe I'll keep them and try again later. Ordered some new red/clear tails from ebay and got the LED bulbs (amber for turns, so they're not just clear) so that way it's not a waste of the flasher too.
(you'll notice it works in the vent, which i turned into a sidemarker that works for park, brake, and turn.)

here's some pictures of what it all included..
11.jpg   10.jpg   9.jpg   3.jpg   7.jpg  

4.jpg  
341012 is offline   Reply With Quote
Unread 03-27-2012, 10:31 PM   #18
rsandwick3
Registered User
1996 ZJ 
 
Join Date: Apr 2011
Location: Frederick, MD
Posts: 20
So, hopefully some of this may help... sorry if I'm blatantly repeating stuff, but maybe it's a good second perspective still.

The flasher relay works mostly like a regular relay, where 12-ish volts across a coil pulls a magnetized contact, which in turn closes a circuit. The difference is that the circuit closure also powers the lamp(s), all while charging/discharging a capacitor. The voltage across that capacitor is what powers the relay coil - a spring holds the contact in the default position until the capacitor reaches a certain voltage, probably around 9V, then the magnet holds it in the other position until it goes back down to a certain lower voltage, probably around 3V.

The resistance in the powered circuit controls the speed at which the capacitor charge changes, but only because it affects the current going through the flasher relay's circuit closure. More current = faster charging/discharging cycle, and less resistance (with approximately constant voltage) = more current.

The real trouble in that last bit is "approximately constant voltage." LED lamps require much more specific (and usually much smaller, though that depends on how many diodes are used in a given lamp) steady currents. More importantly, it's much easier to predict their behavior by applied current than by applied voltage, so LEDs usually need a controller circuit to ensure that the inconsistency of automotive voltage (yes, even with a working regulator) is handled. If they worked for a while and now won't light up at all, it's likely they fried from intermittent overcurrent because the controller wasn't engineered well (e.g., was just some extra resistance stuck in the circuit).

If they are still lighting up, ratmonkey's right on about the digital flasher (I think with '94 you're okay, later years might have trouble with "insufficient current" errors in the BCM). It'd use a discrete timer to control a couple on-board relays or opto-isolators or power transistors, so the timing is independent of the current drawn, and there's no need to put resistors in the circuits (which is a little questionable and maybe dangerous anyway, since they'd have to dissipate a large portion of the same power the original bulbs did, but all as heat instead of mostly as light and some as heat).
rsandwick3 is offline   Reply With Quote
Reply

Tags
conversion , help needed , LED lights , tail lights
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.