Inconsistent rapid turn signal flashing (1 Viewer)

[87warrior]

The left turn signal indicator will randomly rapid flash (as if a bulb has burned out) in my 1999 LC. The next hour/day the rapid flashing will stop and the turn signal will return to normal operation.

- This has happened 3x in the last month.
- I have regular incandescent bulbs for all exterior lights.
- When the rapid flashing occurs, both indicators (front and rear) flash.
- During normal operation, both indicators (front and rear) flash.
- This only happens to the left (drivers side) turn signal.
- I installed tail lights from a 2004 LC about a year ago. I used the tail light harness from Toyota for a plug and play install.

I haven't tried to troubleshoot since I am not really sure where to start. Any help?

 

[OEMGUY0720]

I think if all bulbs on that side are good, the area I’d look next would be the fuses.

 

[ClassyJalopy]

I'd check if any of the wires are shorting or if one of the bulbs fails to light up occasionally. Typically the fast flash is indicative of not enough load being pulled through the circuit. So a busted bulb or shorted wire could cause this.

 

[Trunk Monkey]

^that, if you dinked with the wiring I would inspect that to see if everything is good there.

 

[awesomeissquid]

I had this happen on my other car. Bulb would work and then randomly would stop working before working again. Replaced it. Upon further inspection I found that the bulb filament had broken off and some bumps would cause it to reattach and others would cause it to disconnect.

edit:
Nevermind...I missed the part where it sounds like the bulbs still work when they flash fast so this probably isn’t it.

 

[AlpineAccess]

I would replace the bulbs and go from there.

 

[ramangain]

You *could* get some orange Guidestar lasers and completely trash everyone's eyes that cross the beam path, but I think you may struggle to fit the laser in the OEM light socket.

Just throwing out alternative ideas.

 

[87warrior]

It looks like the front corner bulb just wore out overtime. I was experiencing the rapid flash today and replaced the bulb with a Sylvania I had in the garage. Rapid flash stopped.

The bulb still worked. Both filaments lit up with a 9v battery.

It does look like one of the filaments had shrunk in size. Maybe the tightening of the filament reduced the load the flasher relay wanted to see and triggered the rapid flash.

The brand of the bulb is KOTO and the bulb is a much darker amber than the Sylvania I stuck in there. Is it possible the KOTO bulb is original? If so, that is an impressive life of 22 years and almost 350k miles.

 

[StickyNotorious]

It looks like the front corner bulb just wore out overtime. I was experiencing the rapid flash today and replaced the bulb with a Sylvania I had in the garage. Rapid flash stopped.

The bulb still worked. Both filaments lit up with a 9v battery.
View attachment 2632735

View attachment 2632736

It does look like one of the filaments had shrunk in size. Maybe the tightening of the filament reduced the load the flasher relay wanted to see and triggered the rapid flash.
View attachment 2632737

The brand of the bulb is KOTO and the bulb is a much darker amber than the Sylvania I stuck in there. Is it possible the KOTO bulb is original? If so, that is an impressive life of 22 years and almost 350k miles.

I just had a similar problem with my 2004 LC. The left signal would flash quick but all the bulbs were working. Replaced the front bulb after reading your post and the problem is fixed. I did notice the bulb I pulled out was a cheap piece of crap and appeared to have amber overspray on the metal base.

Thank you. I was dreading the thought of searching for a bad wire.

 

[timeo]

I just had a similar problem with my 2004 LC. The left signal would flash quick but all the bulbs were working. Replaced the front bulb after reading your post and the problem is fixed. I did notice the bulb I pulled out was a cheap piece of crap and appeared to have amber overspray on the metal base.

Thank you. I was dreading the thought of searching for a bad wire.

Had the same issue for several weeks, the solution was to replace the bulbs. Assume one was just intermittently starting to fail.

 

[white_lx]

Also check the tabs that make contact with the bulb. A few months ago, I thought I had a burned out bulb, but found that the tabs were very loose and not making good contact with the bulb. Bent the tabs and put the factory bulb back in.

This may explain the intermittent behavior you are experiencing.