Rear light unit not ok

Grignapoco Posts : 102 Join date : 2020-02-29 Age : 59

After turning ignition switch the rear light did not illuminate.
Front light however did.
After several attempts with the switch it worked but stopped when using brake.

measured 12volt in the plug for braking and normal light.
It seems that my rear led light is on its way to GRiSO heaven.

Pulled on the wiring but no light. Cleaned the plug no result.
Can't find anything that is related to my kind of issue.
Seems like this does not happen verry often.

Sombody a suggestion?

New rear light costs 130 euro grrrr

GRiSO Capo Posts : 10440 Join date : 2013-05-30 Age : 67

Yup, it sounds like it's gone and deaded itself. Being an LED light I imagine there is a transformer in it somewhere to step down the voltage. Chances are that has shat the bed. As you say, failures are rare, I think I've seen two since 2005, on Grisos at least. They do come up on fleabay from time to time but given how reliable they generally are perhaps it would be best to just buy one while they are still available and hope that it remains sound.

GRiSO Capo Posts : 735 Join date : 2014-04-24 Age : 76

The bulbs were all incandescent originally. The headlight was pathetic, so it was first to be replaced -I fitted an OSRAM 7" Round Black Led Headlight (105W).

Tail light is normally second to gain attention. It too was an incandescent duel filament bulb, which is usually replaced with a dual LED setup.

But losing both tail-lights at once is not common. Perhaps the common return wire has lost contact with the frame or battery negative. Simple check with a short piece of wire will determine if it has.

GRiSO Capo Posts : 735 Join date : 2014-04-24 Age : 76

Pete Roper wrote:: Yup, it sounds like it's gone and deaded itself. Being an LED light I imagine there is a transformer in it somewhere to step down the voltage

Sorry Pete, but transformers do not work in a direct current environment.

GRiSO Capo Posts : 10440 Join date : 2013-05-30 Age : 67

Cool. That's why I leave it up to clever people to answer technical electrical questions as a rule Laughing

Grignapoco Posts : 102 Join date : 2020-02-29 Age : 59

Will visit TLM today. Maybe they want to test the taillight. If failed, ill buy a new one.
Sometimes the light will illuminate. After hitting the brake all fall out.

Grignapoco Posts : 102 Join date : 2020-02-29 Age : 59

Taillight start working . The mighty GRiSO repaired itself.
Think the electrical spray did it´s job.
(though i think the complaint will occur soon)

GRiSO Capo Posts : 1449 Join date : 2016-01-26 Age : 69

Deepdive wrote:: Taillight start working . The mighty GRiSO repaired itself.
Think the electrical spray did it´s job.
(though i think the complaint will occur soon)

This points to Kiwi-Dave's point about the "common return" or earth/ground wire.

If more than one electrical component is jointly wired in a plastic insulated box (like the rear light unit)
then a poor or intermittent earth/ground connection for the whole unit means that one component may reach earth through the other component.
so you get apparently weird effects

Check the earth return - blue wire

Grignapoco Posts : 102 Join date : 2020-02-29 Age : 59

Indeed, Kiwi was right.
The reason why i checked again this morning.
Thanks ghetto.

Grignapoco Posts : 150 Join date : 2022-02-25

Pete Roper wrote:: perhaps it would be best to just buy one while they are still available

Took that to heart and ordered one for the shelf

Grignapoco Posts : 102 Join date : 2020-02-29 Age : 59

Complaint was intermittent. So bought new from TLM.
Solved the issue.
Seems like the taillight can be opened. Assume nobody ever did, cause normaly there´s no issue with the taillight´s of GRiSO[You must be registered and logged in to see this image.]
.

Squinternotto Posts : 3 Join date : 2022-04-12

Deepdive wrote:: Complaint was intermittent. So bought new from TLM.
Solved the issue.
Seems like the taillight can be opened. Assume nobody ever did, cause normaly there´s no issue with the taillight´s of GRiSO[You must be registered and logged in to see this image.]
.

I recently faced with the same issue as well, wanted to take out the unit and check if connections are welded in. How does one open up the rear light unit ?

Don Abbondio Posts : 162 Join date : 2015-12-20

The tail light unit is a bit of a pain to take apart as the flat cover on the back is held on with glue/mastic but a heat gun will work. all the LEDs are surface mount and in my case it was moisture that keeps on breaking the LEDs.

Need to try and split it again but I used CT-1 last time Sad

Grignapoco Posts : 102 Join date : 2020-02-29 Age : 59

In the Nissan 350Z scene they make use of an oven. Google on it. The gleu will be softened and therefore easier top open with a bit of force and tools. Is youtube the best friend again?

Don Abbondio Posts : 6081 Join date : 2014-03-14 Age : 69

LEDs are simple devices and the current through them is limited by resistors so as not to exceed the rated current for the particular LED. Often the LEDs are strung in series, still with a current limiting resistor.

There may be a broken track on your tail light circuit board. These are often extremely hard to see but easy to repair. If you have someone that is good with electronics, they may be able to repair it as a spare.

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