Mirror LED indicator flashing rapidly

Maintenance/Repairs
1

Hi all,

I drive a 2010 w169, Mercedes A-Class a180 cdi

and I started to notice that my left LED turn indicator in the mirror on the driver’s side blinks too fast at times, flashing rapidly.

It happens very irregularly. I noticed it first when I locked my car in a parking lot in the dark,
when I saw that, I tried using the left turning signal and those LEDs in the mirror continued to flash rapidly.
Inside the car I never heard a noise or clicking noises so far. My indicator lights in the dashboard also seem to work fine.

Most of the time it doesn’t happen and all turn signals work as they should.

At first I thought a bulb needed replacement, but they are all intact.

Since I’m not knowledgeable about cars, I google’d some info and looked at my grounding wires, they look a little corroded, but are not loose. (it were 3 or 4 brown cables coming together at the same point on the right front side under the hood)

I tried looking at the bulb connectors, but they’re all in a “sealed” compartment and pretty hard to get a good look at in the w169. So didn’t really check the connectors, but all lights work without a problem.

I might take out the left and right indicator lights next to the headlights, as those seem not hard to do.

I looked at my fuse box, but really, I just looked, I know nothing about electronics (or cars for that matter), so I just made sure nothing was loose.
Nothing seemed to be broken or burnt through at first glance.

I tried my blinkers a ton of times and most of the time they work as normal.
so I’m really confused as to why the driver’s side mirror LEDs speed up sometime. There must be a reason.
Is there a bulb on it’s way out? I took out and checked all the bulbs in the rear, all good there.

I wanted to go to a garage, but I’m probably gonna show up and it will all be working fine (that’s how it usually goes)
I haven’t yet found a pattern when it’s most likely to happen, but I’ll keep an eye on it
When it’s sitting in my garage and I test it, it seems to not happen; after driving it a while and when I park my car and lock is usually when I notice it.

The only other thing I ever noticed is that one of the lights in my interior lighting above my head is not working, not sure if that can have anything to do with it?

Has anybody ever have this experience?
I’m curious to see if anyone has had a similar experience and how you fixed it,

thanks in advance!

2

Does your car have blind spot warning? It may be indicating there is a car on your left. Read your owners manual.

1 Like
3

Thanks for the reply!

It doesn’t have blind spot warning,
I can’t see the LEDs in the mirror from inside the car, so I can’t really tell how long it has been going on.
It also flashes in an open parking lot, without cars around it.

Also, apologies for my English, it’s not my native tongue.

4

I would have someone watch the front and rear turn signals to see if they all seem to operate at the same speed. Also check brake lights at the same time. If the only difference is the mirror I would not worry about it.

1 Like
5

@l2389219

“It happens very irregularly.”

From your writing it appears that this vehicle has some LEDs and some light bulbs. Is that correct?

“Is there a bulb on it’s way out? I took out and checked all the bulbs in the rear, all good there.”

Since it happens very irregularly then I suspect that a light bulb could have a partially detached filament that sometimes makes contact, completes the electrical circuit, and functions properly.

At other times the filament makes poor contact, the circuit opens, and the bulb doesn’t illuminate.

The LED is probably on the circuit with the defective bulb.

I have seen bulbs do this. The filament becomes partially detached (only on one end) and moves around. Sometimes vibration or tapping on the bulb or the bulb holder will make or break the contact.

I have removed such a bulb and while looking carefully at the filament and tapping on the bulb have actually seen the filament bouncing.

If you do have exterior bulbs on that LED’s circuit then you could try replacing them.
CSA

1 Like
6

From your writing it appears that this vehicle has some LEDs and some light bulbs. Is that correct?

I think so, the regular headlights and turning signals are bulbs, but I read that the turning lights in the mirrors are LEDs.

Since it happens very irregularly then I suspect that a light bulb could have a partially detached filament that sometimes makes contact, completes the electrical circuit, and functions properly. At other times the filament makes poor contact, the circuit opens, and the bulb doesn’t illuminate.

Thanks, that makes sense!

The LED is probably on the circuit with the defective bulb.

Is there a way to figure this out? I can find a fuse diagram for my car online, is everything that uses the same fuse on the same circuit? I’m a layman when it comes to cars and electronics, so I’m making an uneducated guess here.

I have removed such a bulb and while looking carefully at the filament and tapping on the bulb have actually seen the filament bouncing.

Will definitely check the bulbs that I can reach myself and give 'em a close inspection, thanks!

I appreciate the input!

7

@cdaquila Carolyn, I don’t understand why the original post in this thread was flagged.

1 Like
8

me either (10 char)

1 Like
9

the system automatically flagged the post because the OP and one of the respondents registered from the same IP address within a short period of time.

10

My apologies! I made two accounts and used both to reply. Sorry.

11

I cleared the flags – you’re good to go, @jasper.vo

1 Like
12

I know that the right rear turn signal bulb was changed recently (not by me), so I took a look at it.
The Wattage and Voltage were correct, however, for testing purposes I decided to switch the left with the right rear turn signal bulb, to see if the LEDs on the left side would still be flashing or if it would maybe change to the right side.

Now 4 days have gone by since I switched 'em from sides and the LEDs haven’t acted up so far, color me confused, but I haven’t had it happen since the switch; of course it might still happen in the future.

13

My sister had rear turn signal problems on her Saab 900. Switching bulbs like you did fixed it (…back away slowly…), never did find out why.

1 Like
14

Hmmm, so now the LEDs stopped working completely for a while (when locking the car and when using my turn signal)
and some hours later they started flashing rapidly again

I’m probably gonna pay my local garage guy a visit and explain him the symptoms; I have too little knowledge myself to start fiddling around