Turn signal and hazard clicking way too fast.

Hi all. Long time member from the BMW CS Registry. Doing some troubleshooting on my 72 3.0 CSi, driver:

Symptom:
Turn signal and hazard clicking way (WAY) too fast, almost a constant clicking. Turn signal actually faster.


Completed:
- New nickel base bulbs (7506, 5008, 3893) for turn, side, license and rear.
- Cleaned fusebox contacts.
- I checked grounds by taillight (jumper wire) and it didn't effect anything.
- Used to click at a normal rate but I recently re-taped loose wiring in the trunk, firewall, glove box, which fixed a shorting issue but then I discovered this bug.


Thoughts on next steps?
(I have a feeling I need to go back to the brass base bulbs, 1156...)

Check the ground connections at the turn signal housings. They are riveted into the housings and prone to corrosion. Good luck.

Flashers pulse according to amp draw. That's why additional resistance has to be added when low draw led's are used. Maybe your new bulbs are higher wattage?

bill: I checked the taillight and front turn grounds and all were good.

Ed G: I read about that too. My current bulbs are Osram 7506 nickel 21w and I found a comment about Hella brass 1156 being spec'd 21w but metered at 27w so I'll try that next (cheap test).

I'll post update.

My understanding of the flasher circuit is as follows:

1) The green instrument arrow light blinks in synchrony with the external markers when everything is OK. The frequency may be affected by the load.

2) If the load is not sufficient (open circuit, bad contact, burned bulb) then the other external marker will work but the green indicator will not. The bulb is in series with the coil of the relay that drives the indicator.

3) The emergency flasher internal red light flashes as the opposite of the external lights because it is connected between 12V and the bulb. When the external bulb is ON there is 12V on both sides of the red light and no light. If there is no load at all (open circuit) the red light will not illuminate.

4) If the load is too high (higher wattage bulbs) the indicator should still be in synchrony, but I believe the solid state part of the circuit may operate at a higher frequency. Because the circuit to the external lights is solid state and the indicator is a relay it is possible the green indicator cannot keep up with the frequency of the lights and just lags or appears the be always on or off.

To troubleshoot 4) I would disconnect rear marker and then front marker until green indicator stops, then reconnect one or the other. If indicator blinks with no external bulbs then there is a short or current leak in the circuit, maybe water in the socket, maybe mechanic trying to get even with you for some personal affront.

Your symptom is consistent with 4). It is not a matter of checking the grounds but rather resistance of the signal wire to ground with no bulbs. Should be infinite.
I bet there is a short there somewhere or you have been flirting with your mechanic's daughter.

Arde: Quite helpful comments. I have to verify the checks again but its looking like a short somewhere in the rear.

Follow-up: I decided to swap the original turn signal relay for an electronic flasher, as per http://www.bmw2002faq.com/content/view/41/32/

My fuses have always stayed intact so I'll return to the short/corroded-wire/high-resistance/poor ground issue another time. The electronic flasher works very well.

Arde said:

My understanding of the flasher circuit is as follows:


2) If the load is not sufficient (open circuit, bad contact, burned bulb) then the other external marker will work but the green indicator will not. The bulb is in series with the coil of the relay that drives the indicator.

Click to expand...

that was just my case on my euro 3.3L-automatic....

thank you arde!

Rusty said:

Follow-up: I decided to swap the original turn signal relay for an electronic flasher, as per http://www.bmw2002faq.com/content/view/41/32/

Click to expand...

The 2002 guys seem to use an Littlefuse electronic flasher p/n EFL300. I couldn't find a source for the EFL300 - my local chain auto parts store carries two types of three terminal, electronic flashers: Littlefuse FLR758 and FLR759. But since I'm not in a hurry, instead of taking a chance that one of those would work, I decided to track down the part recommended on the 2002faq.

I couldn't find a source for the Littlefuse EFL300 on the web (though I did learn that typing "flasher" into your search engine will uncover some pretty raunchy websites!). I found a flasher interchange chart at http://ceclighting.com/user/download.php?table=_Brochures&field=broc_pdf_file&key1=74 This tells me that the Littlefuse EFL300 is equivalent to a BUSS NO.246 . Does anyone know if "Bussman" and "Buss" are the same company? Seems likely. Amazon carries the Bussman NO.246 for $11.88 (RockAuto and other sources were higher). I'll try one of these Bussman NO.246's, and report back.

jmackro said:

The 2002 guys seem to use an Littlefuse electronic flasher p/n EFL300.

Click to expand...

I forgot to mention the flasher I ended up with ... NAPA EL-13 Electronic flasher, easy to acquire. Only quirk (trivial) is on turn signal cancellation, there is a half "pulse". I did reroute the original harness ground to another ground wire.

siscobmw said:

that was just my case on my euro 3.3L-automatic....

thank you arde!

Click to expand...

Not possible! Euro and automatic do not go together.
Brussels will confiscate your passport if they catch you driving automatic.

Rusty said:

I forgot to mention the flasher I ended up with ... NAPA EL-13 Electronic flasher, easy to acquire.

Click to expand...

OK, I got my electronic flasher conversion done, using the EL-13 part that Rusty mentions. My local Carquest store cross-referenced that NAPA EL-13 number to their own 7312. The flasher I got says "Carquest 7312" on the box, but the part inside is marked "cec EF-33", which makes sense - that's the CEC number shown in the left column of the table I referenced in post #9 above (I have no idea what "CEC" stands for). My cost after tax was $12.95

The Littlefuse EFL300 number referenced in the BMW2002faq (see post #6 above) seems to be obsolete - I tried O'Reilly and NAPA, as well as Carquest, and none could find any reference to that number, or to the different manufacturers' cross-references on the table I referenced in post #9 above.

Only quirk (trivial) is on turn signal cancellation, there is a half "pulse".

Click to expand...

Yea, mine does that too. Sometimes 1-1/2 extra pulses. So with my old flasher, the indicator bulb would quit early - now it puts in overtime!

FYI, 2002faq link aforementioned is dead.

Try this one:
https://www.bmw2002faq.com/forums/topic/85984-signal-flasher-upgrade-easy-to-do-what-a-difference/

BAD LIGHT GROUND

Where is the turn signal flasher relay located? In the fuse area?

The turn signal/hazard relay clips to left side of steering column.

Worked great! Now consistently blinks including on the dash.



Bought the flash unit on Amazon
NOVITA EL13 Flasher https://www.amazon.com/dp/B001I1QPNG/ref=cm_sw_r_cp_apa_50IgAbFGJ3Y82

And the plug on eBay

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/400667177039

Thxs for the link

teahead said:

Worked great! Now consistently blinks including on the dash.

View attachment 33484

Bought the flash unit on Amazon
NOVITA EL13 Flasher https://www.amazon.com/dp/B001I1QPNG/ref=cm_sw_r_cp_apa_50IgAbFGJ3Y82

Click to expand...

Flasher ad carries some "interesting" dimensions. :eek: