Noisy hazard lights

daveiezzi

daveiezzi

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Joined
May 21, 2020
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7
Location
West Chester, Pennsylvania
I have an 04 TJ Sport with a 4.0L & a 5 speed. This was purchased with a salvage title & it may have had some water in places where it shouldn't have had. The rear passenger taillight didn't work & that was a missing ground. The turn signals didn't work & that was solved with a new relay (#EP27C - no LEDs, original lighting). The multifunction connector was fried & that was replaced (Crown Automotive #5183442AA). The multifunction/ turn signal switch was pretty corroded so that was replaced too (#RJ5058003 - without fog lights). I swapped out all of the under hood fuses too with correct amperage on each.

After all of this, the hazards/ flashers still chatter when turned on, which was an original problem. I get the chatter with the key in/ running & the key out. None of the lights, front or rear, are on when the hazards are engaged.

I'm sure I have a missing ground/ 12VDC or a short somewhere under the dash or in a connector.

This is the last thing I need fixed before I can get an enhanced inspection in PA, which is required for a salvage titled vehicle.

Has anyone seen this? Thanks in advance for any help.
 
I've got an '03 Sport with factory fogs - there is a separate relay for the hazards.

Mine does almost the same thing on the hazards - the hazard flasher buzzes when depressing the hazard button. Turn signals all work OK. I have replaced the hazard flasher with no change. Jeep has factory fogs.

I am beginning to suspect there is a problem with the Multi-Function Switch (MFS) and in researching have found there appears to be several issues with the MFS design. And that after-market switches are not up to the task. And to make matters worse, they appear to be Discontinued from Chrysler.

There is a pictorial and instructions on how to fix some of the issues with the switch. I've not yet torn into mine to see if something inside of the MFS could cause the buzzing issue. Considering the various described issues and repair methods, I think the chances are pretty good the problem is in the MFS - I just don't know if it's repairable or not, and we're traveling at the moment so will not be able to dig into it until next weekend.

The above FWIW - and if anyone has any additional input or suggestion, please feel free to chime in! :)
 
So, Mopar refers to the 5 pin device on the Multi-Function Switch as a "combination flasher", not a relay, as per the paragraph below from the 2004 Jeep Wrangler User's Manual.

I have attached the pretty simple diagram of the "combination flasher" & how it operates in conjunction with the front & rear lights & the flasher or turn signal switches.

Either 12VDC is sent to pin "L" for the flashers or to pin "L1" for the turn signals (ignore the LED identifier in the diagram as I'm not using LEDs). Assuming the turn signal & flasher switches are operating correctly (I replaced the MFS so I'm hoping so), I either have the wrong "combination flasher", I installed an EP27, or one of the lights has a weak connection or faulty ground. Remember, the turn signals & brakes all operate correctly; just the flashers don't operate.

Lastly, I was told by a design engineer that the chatter normally occurs when there is insufficient current.

Any additional input is appreciated.
=========================================================================================

OPERATION
Constant battery voltage is supplied to the flasher so that it can perform the hazard warning function, and ignition switched battery voltage is supplied for the turn signal function. The Integrated Circuit (IC) within the combination flasher contains the logic that controls the flasher operation and the flash rate. The IC receives sense ground inputs from the multi-function switch for the hazard flasher, right turn signal, and left turn signal. A special design feature of the combination flasher allows it to sense that a turn signal circuit or bulb is not operating, and provide the driver an indication of the condition by flashing the remaining bulbs in the affected circuit at a higher rate. Because of the active elements within the combination flasher, it cannot be tested with conventional automotive electrical test equipment. If the combination flasher is believed to be faulty, test the turn signal and hazard warning system prior to replacement.

TJ Flasher Turn Signal Circuit.jpg
 
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Thanks CharlesHS, I found the MFS Connector on page 8W-80-36 & it looks like the hazard flasher feed is on pin 11 of the 20 pin connector (black/ white). The left turn signal is on pin 2 (gray) & the right turn signal is on pin 6 (tan).

It also shows left turn/ stop & right turn/ stop on pins 4 & 5 respectively (dark green/ red & brown/ red).

I'll check those outputs.
 
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daveiezzi said:
Thanks CharlesHS, I found the MFS Connector on page 8W-80-36 & it looks like the hazard flasher feed is on pin 11 of the 20 pin connector (black/ white). The left turn signal is on pin 2 (gray) & the right turn signal is on pin 6 (tan).

It also shows left turn/ stop & right turn/ stop on pins 4 & 5 respectively (dark green/ red & brown/ red).

I'll check those outputs.
Click to expand...

I noticed the MFS in 8W-51 and thought that would lead you in the right direction...
Thanks for the correction...
 
@daveiezzi -

Hey Dave, did you get this figured out? As noted above, I’ve got darn near the same issue with the hazards on mine as you described.
Several months back I did buy a new relay for it and installed with no change - but after doing some recent research and the above that is talking about a 5 pin relay. Quite frankly, I dont remember what I bought for mine, but I believe I ordered what I bought from the Parts Manual for my ‘03 - or at least the Jeep P/N to find an interchangeable one.
 
MrMark52, I still haven't figured out the chattering hazards yet. I did replace the relay/ combination flasher early on with an EP27C which I picked up at Pep Boys for ~$15. I searched everywhere to confirm that the EP27C is the correct 5 pin device for the 2004 TJ Sport with no success. Many of the auto supplier website search engines identify the EP27C but I'm still not convinced. I'll post if I get anything figured out.
 
daveiezzi said:
MrMark52, I still haven't figured out the chattering hazards yet. I did replace the relay/ combination flasher early on with an EP27C which I picked up at Pep Boys for ~$15. I searched everywhere to confirm that the EP27C is the correct 5 pin device for the 2004 TJ Sport with no success. Many of the auto supplier website search engines identify the EP27C but I'm still not convinced. I'll post if I get anything figured out.
Click to expand...
Hey Dave - get it figured out yet?

Being as it’s but naked cold in Dallas right now and for the next week - and between our new to us motorhome and the Jeep - its looking like Amazon is going to be our closest friend.

Might as well order to have whatever I need on hand for when I can get outside. 😀
 
MrMark52 said:
Hey Dave - get it figured out yet?

Being as it’s but naked cold in Dallas right now and for the next week - and between our new to us motorhome and the Jeep - its looking like Amazon is going to be our closest friend.

Might as well order to have whatever I need on hand for when I can get outside. 😀
Click to expand...
Dave,

For when you do get this - shortly after I wrote the above, I went to AutoZone and got the LM470 as everyone has suggested. Problem solved!
Hazard flashers flash like they should (and never have since we got the Jeep at 103k miles - and that includes wasting money on both a new EP-27 as well as an AutoZone MultiFunction switch -although I did find one of the terminals on the plug was getting hot and I need to fix. I’m gonna put the old OEM MFS back in).
 
Gunnersmate said:
The correct procedure for correcting this problem is turn the Left knob on the stereo clockwise
Click to expand...
Yeah, thought about that! 😀 But since the only time I use the hazards is when for whatever reason I represent a hazard (unlike some in our society who think the hazard lights are to be used whenever they are a hazard ano continue to drive down the road - pardon my frustration, but they are IDIOTS!).
 
Created an account so I could comment :) but been tracking down a parasitic draw the past few days on my 01 Silver Anniversary TJ. In the process, I found that my turn signals worked but the hazards would only cause my EP27 flasher ( I had put in in a year ago for the LED turnsignal bulbs) to just buzz. Got another EP27 and it did the same thing. So I suspected the Multifunction switch. That didn't fix it either. So I dropped back to the schematics and my meter. I got to reading online people suggesting the LM470 as the correct model, but according to the manufactures web site they are both the same. I went ahead and picked one up today and sure enough the packaging shows that it has a 300 watt max where the EP27 is just 165 watts. Put the LM470 in the Jeep and what do you know my hazards started working. In the mean time I fixed the parasitic draw with a new ignition key cylinder (the key could come out in any position) and replaced the ignition switch itself while I had the column apart. So yes, the LM470 is probably the flasher that is needed for most of these issues due to the higher capacity.
 
Thanks - I need to keep an eye on mine. I never use them but I pushed the switch to check a bulb the other day and there was a noticeable delay before they started working. Maybe my relay is on the way out.
 
Wow, just bought the LM470 from Quadratec, their #55213.2002, for $19.99, installed it & I have flashers. I can't give enough thanks to Kyrenegade for the fix post.
I'm a little ticked that the EP27C is called out for the stock 2004 TJ everywhere from AutoZone to Pep Boys & others, including the Mopar websites. I will admit, I just checked RockAuto & they call out the LM470 (should have gone there first). I can cross off one of the many "to do" items for the Stomper. Thanks again!
 
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