Right turn signal flashes fast, all bulbs OK. Huh? - PeachParts Mercedes-Benz Forum

MattBelliveau · #1 12-19-2005, 01:03 PM

Since I got the car. The right turning signal has been flashing fast, as if there is a bulb out. I'v esince replaced all the bulbs and have not been able to cure it. Could this be a flasher relay going out? If so, where would I find it, under the center console?

G-Benz · #2 12-19-2005, 11:40 PM

I believe you have a combination relay located by the fuse box. It actually serves several purposes...flasher, rear window defroster relay, etc. A bit pricey.

I would think if your flasher was acting up that BOTH signals would behave in the same manner.

I'm inclined to believe that you have a grounding problem somewhere...specifically the rear taillight housing. Check the metal rails where the bulbs reside and make sure they are seated firmly in the tracks. Over time, they get loose and cause all sorts of weird lighting issues.

I'm guessing much of this, since I'm not sure what you really have equipped on your model...sorry.

zcc · #3 12-20-2005, 01:23 AM

Check the right turn lights (front and rear) u will find one lamp that is not working or at leat night be not original; replace it and start ur car again : ))..

One more thing could case such problem is the relay that is located in the instrument cluster. I hope it's not that.

Carlos Serrano · #4 12-20-2005, 10:12 AM

I agree with G-Benz on the grouding problem, I had this problem before in non MB's and usually that is the reason.

MattBelliveau · #5 12-20-2005, 10:27 AM

Grounding problem, even if all the bulbs are actually working? They all glow, just signal fast. Thanks guys.

G-Benz · #6 12-20-2005, 02:41 PM

My VW had this problem too...it was a ground wire...

MattBelliveau · #7 12-20-2005, 02:45 PM

I will look into that. Thank you, all.

Hans47 · #8 01-09-2006, 05:48 PM

Matt, please let us know if grounding was the problem. I too have this problem on my '88 420 SEL and it was preceded by a problem with my rear left sidemarker lamp that would not light. When I opened the rear tail light assembly the side marker socket had a 21W bulb installed instead of a 10W bulb. I installed a new 10W bulb and the side marker still would not light although the new bulb was fine when I tested it on the right rear side marker. Then I wake up this a.m. and the left turn signal flashes rapidly. No warning lights lit on the dashboard. Fuses are fine. Thanks.

G-Benz · #9 01-09-2006, 10:11 PM

Hans47:

Check the metal rails that hold the taillight bulbs in place. They get loose over time with vibration and create all sorts of weird ground problems...even if the bulbs all seem to work and the bulb out indicator doesn't come on.

Press on the metal rail near each bulb and see if the bulb behavior changes at all.

Also, is it the side marker light that is out on your car, or the extra fog light circuit? Note, the fog bulb is absent on one side so there may be a socket available but no actual circuit to power it.

Hans47 · #10 01-10-2006, 11:48 AM

Thanks, G-Benz. The rear left side-marker lamp is not functioning. The one that wraps around from the main left tail light and prevents someone from crashing broad-side into the car. I'll check those rails.

The turn signal saga continues. Yesterday evening while driving the right side turn signal started to malfunction like the left turn signal (i.e. blinking 5X faster than normal). Must be a coincidence relative to the side-marker light problem (I guess when it rains, it pours). Sounds like the turn signal combo relay that also controls the hazard light is the problem.