Technical No brake lights, rear fog or reverse light!

[Delux]

Hi, I’ve just stumbled on an issue with the rear lights at my MOT test for a 2010 4x4 - I’ve got taillights & rear indicators but no brake lights, no third brake light, no rear fog light and no reverse light.

Indicator on the dash illuminates when rear fog light switch is pressed.

Front lights and all indicators work. Front fogs work. Number plate lights work. No bulb out warning.

Tried disconnecting and reconnecting the brake light switch but no joy.

Any ideas why all these rear lights in the lower cluster & third brake light may suddenly not be working?

Thanks!

 

[koalar]

Rear fog and reverse share this F31

If you put the indicators on do the rear light change intensity

If you press the brake pedal does the indicators change speed

Does anything change if you put the rear wiper on

Do you have a multimeter

 

[Delux]

Thank you for responding @koalar . Yes I have a multimeter. What can I test?

I’ll do the other things you mention tomorrow and report back.

 

[Delux]

Ok… some weird stuff going on… fuse 31 5amp is fine but I replaced it.

See first pic attached.

Car on, all tests as suggested still no lights except tail lights, but with rear wiper on & hazards on a slight change in tail light intensity can be seen.

Fuse 37 was empty… I found a wire with two piggyback fuses, see pic 2 with 10amp and inserted that.

Now with car on the third brake light and right tail light are on permanently the moment the car starts.

Lights on and both tail lights and third brake light are on.

Tests as above results the same.

No fog light, no reverse light. No brake lights. And with 10amp fuse in third break light and right tail light on permanently.

What kind of voodoo is this?

 

[koalar]

Mmm third party wiring might complicate things

What's been added, radio, reversing camera, dash cam, tow bar

How long have you had the car

Must have been working for the last MOT

With F31 removed and the ignition on


Multimeter on volts one lead on an earth the other touching the terminals where F31 was one side should measure battery voltage


Just touch the terminal don't jam the probe in, you don't want to spread them and cause problems further down the line

 

[koalar]

Earth here if you can't find a convenient bolt

Either of the green, pin 4 or 5

Again don't jam the probe in just gently touch the top

 

[Delux]

I’ve been restoring the car to roadworthy condition for a few months after buying it spares or repairs - the number of undisclosed faults has been staggering, sad the sellers were so dishonest, and of course I didn’t suspect for a moment that the brake lights weren’t working if the taillights were. The only consolation is that is was cheap and if I can sort this wiring it’ll be a great little car again.

The extra cable is for a dash cam but I’ve put a 10amp fuse in there now. Still the same. No additional things have been added.

Thank you for those checks, I’ll do them now and report back.

I’ll also pull the light clusters and look for anything obvious and replace some bulbs for good measure.

 

[koalar]

Which rear clusters do you have

Normal like most pandas or the round type

 

[koalar]

Do the same for this fuse, check the volts

That will be both the ignition on feed and ignition on accessories feed to the body computer done and dusted

 

[koalar]

Fuse 37 should be 10 Amp

It goes to the brake pedal switch, I suspect the switch is faulty or been dislodged/kicked and the fuse removed to stop the battery going flat

Try plugging in a 10a fuse and disconnecting the brake pedal switch

Fingers crossed the third brake light will go out


It's located in the passenger footwell

brake lights on at all times | FIAT Panda (Mk3)

Morning. Have a 2008 1.3TD which is very reliable. However, both brake lights come on with the ignition and won't go off- and clearly won't show when I am slowing down! Changed all the bulbs and looked closely at electrical connection but I am untrained in these matters and would appreciate any...

www.fiatforum.com

 

[A3jeroen]

Are the 21W/5W bulbs in the right way?

gr J

 

[Delux]

Normal rear light clusters.

I did he tests on the fuses and they’ve got battery voltage.

So I removed the rear light clusters and fitted new bulbs.

Looking at the white connectors the earth terminal on both seemed dirty, cleaned them up and also closed the gap between the upper & lower terminals.

I noticed the pins on the light casing were at an angle but the central one for the earths was out of line in both clusters - that can’t be right? Anyway I made them all match then clipped them into place. Much firmer connection now I think.

Turned on ignition and now I had all three brake lights on… so unplugged the brake light switch… no lights on ignition now.

Started car, turned on lights, hazards and fog - all illuminated. Popped car in reverse - light came on. Result.

Seems the brake light switch is telling the car the brakes are on all the time. I’ll order up a new one cos pulling it apart & cleaning it didn’t help.

Looks like it’s almost fixed

Will report back here in a day or so when I’ve fitted the new brake light switch. Hopefully that will cure that issue.

Thank you for the help so far @koalar !

 

[Delux]

Ah just seen the link. I’ll check that out now.

 

[Delux]

Frustratingly fitting a new brake light switch has not cured the problem of having the brake lights on permanently.

I’ll start a new thread for that singular topic.

 

[koalar]

Yes the connector pins should be straight

There's been an intermittent connection, due to the pins spreading, instead repairing the connector, they have twisted the pins, which does work temporarily

rear light cluster repair | FIAT Panda (Mk3)

pretty self explanatory this one was flashing double speed when using the brake 10mm socket is so much easier press here to release the connector above done forget to clean up the other half. Scrap with a screwdriver blade is normally enough above, Line up these First.

www.fiatforum.com

 

[Delux]

Thanks @koalar I’ll straighten them up.

I’ve started a new thread for the brake light issue.