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Very dim rear indicators and brake lights

Posted: Thu Jul 06, 2023 11:29 am
by jimmy167
Found this problem today ,rear indicators very weak and both flash weakly ,the brake lights are also weak .
if it was only flashers I would be thinking of getting a new flasher unit . It could be a bad earth , apart from the earth points at the rear lights where else should I check .

Re: Very dim rear indicators and brake lights

Posted: Thu Jul 06, 2023 11:49 am
by geoberni
Is it only the rear lighting?
What about rear/tail lights?
They have the same supply as front marker lights so are the rear dimmer than the front?
If so, it can only be the earth path. It's the only common part of the circuitry.
rear indicators very weak and both flash weakly
What? Are you saying the same thing twice, i.e. the lamps are 'weak' illumination; because the front and back use the same flasher, so the rate of flash has to be the same. If the rear is flashing at a slow rate, so must the front be.

Re: Very dim rear indicators and brake lights

Posted: Thu Jul 06, 2023 11:57 am
by jimmy167
Just been checking again ,the brake lights work fine ,the indicators all flash weakly indicating left or right ,front is stronger than rear but indicator arm down or up all 4 flash weakly .
Put on the four way flasher the front is normal but nothing at the rear .

Re: Very dim rear indicators and brake lights

Posted: Thu Jul 06, 2023 12:13 pm
by geoberni
jimmy167 wrote: Thu Jul 06, 2023 11:57 am Just been checking again ,the brake lights work fine ,the indicators all flash weakly indicating left or right ,front is stronger than rear but indicator arm down or up all 4 flash weakly .
Put on the four way flasher the front is normal but nothing at the rear .
Right.... :tu1:
In which case, that's potentially looking like 2 issues. As the hazard switch is an addition to the system, there might be something common in that area.
Can we assume all has been working fine for many months and this is a new problem?
Don't wish to offend but it wouldn't be the first time the whole story hasn't been given at the start.

Some random thoughts here...
Do you have a multi-meter and can you use it?
Check the voltage at the Flasher Unit, the Supply In and the Flashing output.
If you connect together the In & Out of the Indicator Flasher, then when you operate the Indicator stalk the appropriate side should illuminate steady (and equally bright).
Do you have a diagram of how the Hazard wiring has been included?

The standard Indicator circuitry is Flasher Unit, Selector Switch, then split to Front and Rear. So there's a good chance you have connector problems.

Re: Very dim rear indicators and brake lights

Posted: Thu Jul 06, 2023 1:05 pm
by simmitc
but indicator arm down or up all 4 flash weakly .
Are you saying that when you operate the indicator switch, either left or right, then all four lamps flash at the same time?

Does "weakly" mean that the flash rate is slow or that the lamp is dim?

If the flash rate is always constant and correct (between 60 and 120 times per minute) then that suggests that the flasher unit is OK; but if the rate is very slow then the flasher may be faulty. Dim lamps suggest a lack of power due to poor connections. However, the standard flasher is not designed to operate four lamps at once, so if they are all on, then that is a problem.

When was the hazard light switch fitted? Has it ever worked correctly? I am wondering whether the hazard wiring has creatred problems.

Re: Very dim rear indicators and brake lights

Posted: Thu Jul 06, 2023 2:40 pm
by jimmy167
The Hazard four way kit was fitted 3 years ago when the car was in at a Morris Minor Specialist getting a new crossmember .
I will check all the connections and earth points .
When I say dim ,very weak and all four flash weakly ,put hazard on front flash rear nothing .
I will look out the wiring diagram for the 4 way hazards .

Re: Very dim rear indicators and brake lights

Posted: Thu Jul 06, 2023 4:22 pm
by jimmy167
Problem solved ,I undid the earth points at both sides cleaned them up put a stainless washer did them up and everything works .
I should have known ,first thing to check with electrical faults is the earth points .