Louis maccarone

I recently bought a 2004 Jeep Grand Cherokee special edition and the problem I'm having is when I turn my right turn signal on the rear bulb keeps blowing out doesn't happen all the time I've had the truck for a little over a month and just in the past three or four days it's happened twice now is there anyway to fix this so it doesn't continue to happen now it seems like it only started happening once I towed my boat with it and used the wiring harness to hook up to my trailer. and on the wiring harness itself it actually has about a 2ft extension that you can put on it to make it reach the trailer like if it was too short but it's not so I could probably just take that part off and it wouldn't be an issue at all meaning the actual extension is not needed but I'm not quite positive that is what is causing the blinker bulb to blow has anybody had this happen or know how to keep the ball from blowing the last thing I need is a ticket for having a blinker bulb out.

Noah911

I wonder if are you obtaining the same bulb from the same store? Maybe a bad run in production for this bulb at that store, or a poor quality bulb brand you are using?

Do they make Mopar brand, or dealer only acquired bulbs?

Noah911

It is probably due to high current draw though. A poor connection will cause this..

Here's why;

A bulb is rated in watts. Watt is unit of power. For example, 1 horsepower is about 755 watts. In DC electricity a watt is the voltage multiplied by the current flow. The bulb's rating is based on specific voltage or voltage range. For cars that's ~12VDC. So, a 12 watt bulb will draw 1 amp of current at 12VDC (12VDC x 1 amp).

Here's the fun part. Suppose the bulb is getting only 10VDC. It would then draw 1.2 amps of current (10VDC x 1.2 amps). That current level could blow the bulb.

What causes such a situation? A bad connection between the power source and the bulb is the usual culprit.

Cleaning the connection real well and applying bulb dielectric grease could help if that is why, unless it is a short.

There may be measurably less than 12VDC getting to the bulb...

Louis maccarone

[QUOTE=Noah911;3572373]I wonder if are you obtaining the same bulb from the same store? Maybe a bad run in production for this bulb at that store, or a poor quality bulb brand you are using?

Do they make Mopar brand, or dealer only acquired bulbs?[/QUOTE

well you know what I'm not quite sure so I'm going to go ahead and purchase a few bulbs today and see what happens then I will get back to you later on this evening and let you know I work from 8 to 4 so I'll do it on my lunch break

Louis maccarone

Well as crazy as it sounds as we speak I'm on my way to work and I still put on my blinker just because it's a habit and it's law and my right rear blinker the one that I've been having issues with is working perfectly fine like out of nowhere so I'm not sure what's going on on the truck is having electrical issues but the only thing I did do was unplugged the one foot extension of the trailer connector it had a 1 foot extension on it I guess maybe the guy who owned it before me full the trailer and it was just a little bit too short to reach his connector so I unplugged it and my lights are working just fine hopefully it stays that way I will keep you posted

Noah911

Since you have a 2004 Grand Cherokee.. You have tailight assemblies with a circuit board in them, instead of having traditional bulb sockets. The circuit board is hidden inside of the assembly. These circuit boards can also go bad too.

If the bulb goes out again (if it came back on, then it is not blowing its filament), you can swap your assemblies around. Only two bolts I think hold them down. Unscrew them, and pop the assemblies out. Connect the right to the left side, and the left to the right side to see what happens. If the opposite side assembly doesn't work when connected too, then you may have a wiring problem leading to the assembly on that side, possibly a weird short somewhere?

I'm not sure about the extension you have? That could be the reason it sounds?

XJRed96

I would suspect the circuit board. replaced quite frequently on these vehicles. as well as on other chrysler products with similar lamps (i.e. Caravans, town/countrys)

TCP64

The fact that you pulled the extension and everything is ok points to the extension being the cause. One of the wires which carries positive voltage is occasionally rubbing against a ground (or negative) lead. Toss the extension. If it starts doing it again then focus on the tail light circuit board and wiring harness connector. And could you use some punctuation in the future. Your posts are very hard to understand without it.

Louis maccarone

I am sorry that I haven't use punctuation as I am doing right now I am at work and I just press the microphone button and I'm just talkin and my phone is actually writing it for me so that's why the punctuation is terrible so I will just type it in the future sorry about that.

dave1123

If you should still have the problem, you can unplug the trailer tow module and connect the harnesses directly together without it. It's behind the cargo area side panel, which side I'm not sure.

OMG! I just looked at my FSM to see what's involved with the trailer tow system and there are RELAYS for each function of the tail lights! Good luck figuring that out!