Buzzing Emergency Relay

CharlesHS

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Joined
Mar 10, 2020
Messages
5,594
Location
Jacksonville FL, Quezon Philippines
History behind this is problem...
A couple months ago I installed the BMB LED tail lights, license plate lowering bracket and LM470 LED relay.
Tested parking lights, brake lights, turn signals and emergency flashers after installation; all functioned perfectly.
Jeep sat for 3 months while i was on vacation; although my brother did drive the Jeep around to circulate fluids (once a week).
When I get home from vacation I drove 600 miles round trip to visit my my son and his family; used the emergency flashers once and they worked fine.
A couple days after getting home I found that when energizing the emergency flashers the flasher relay will buzz loudly, the green turn signals in the instrument cluster will pulse dimly along with the front and rear turn signals; both turn signals lights work fine (relay doesn't buzz) when signaling to make a turn.

What I have done to trouble shoot the problem....
Removed front parking light bulbs individually, inspected wiring and cleaned receptacles; tested and relay still buzzes when emergency flashers are on....
Disconnected BMB LED tail lights at factory tail light connector, inspected the wiring for chafes and poor connections (no problems found); relay still buzzes when emergency flashers are on...
Replaced the LM 470 with a new relay; relay still buzzes when emergency flashers are on...
As a test I installed the factory style 12V flasher relay; the emergency flasher indicators in the instrument cluster flashed normally, but when the turn signals are used; the lights hyper flash as you would expect. VERY ODD....
Replaced the MFS turn signal stalk; relay still buzzes when emergency flashers are on....
Watched all LEDS in tail lights while turn signals are on; all rear tail light LEDS (side and rear) work properly. None of the LEDs are flickering or burned out.
Tomorrow I am going to purchase new front turn signal and side marker bulbs as a test....

I believe I recently read about a Jeep owner on this forum with a similar problem, but I can't find the post.
Can anyone offer additional troubleshooting ideas for this problem ?
 
I can’t offer any solution on this off the top of my head, but I have noticed since adding the Savvy lights and the LM470, the lights will blink at inconsistent speeds. I don’t know if it’s a combination of the incandescents but it’s been something I’m keeping my eye on.
 
Mine is kind of the same way too, I’ve tried 2 LM470 flashers with the same result. Stock flasher hyper flashes, but works normally on hazard.
 
UPDATE:

Today I installed new 194 and 3157 bulbs; the flasher relay still BUZZes when the Emergency Flashers are on...
I have ordered LEDs from Superbright LEDs for the front side markers and turn signals; all bulbs operated by the LM470 relay will be LEDs.
I will update you once they arrive.
 
Last edited:
UPDATE:

Installed the LED front turn signals and side marker bulbs, tested the Emergency flashers and the relay still BUZZes...
Rechecked the wiring harness connectors, ground connections, bulb sockets and found nothing that explains the BUZZing relay when the flashers are on...
 
UPDATE:

Installed the LED front turn signals and side marker bulbs, tested the Emergency flashers and the relay still BUZZes...
Rechecked the wiring harness connectors, ground connections, bulb sockets and found nothing that explains the BUZZing relay when the flashers are on...

Defective MFS or melted MFS connector?