Interesting but extremely annoying gremlin I cannot trace!

[UP04 WRK]

Hi,

I have a annoying issue I cannot find anywhere on the forum or internet.

My issue is..

Indicators flashing very fast and rear bulbs not bright.
When braking camera comes up on screen annoying at night!
Hazards make the heater display pulse in sync with them -
Also flashes the truckman centre brake light at the same time.

I have checked the bulbs..all good and dry
I have pulled off the trailer control module to verify that wasn't at fault
I have opened the trailer plug which is all dry and disconnected it to verify also

There was an auxiliary relay which was seriously rotten positioned on the right hand side under the bonnet which I have replaced. I believe this to be the tow bar electrical control which I am not entirely sure as when I took it off the indicators still flashed dimly.

No one can shed any light.

Has anyone experienced this at all? I would be very happy to solve this myself..

Thanks for any help whatsoever...

 

[Old.Tony]

The very first thing to try is this: grab a 10mm spanner/socket OR Philips screwdriver and undo the bolts retaining the LEFT tail light. Pop it out. There should be TWO grey plugs - undo them BOTH. Give them a spritz with electrical contact cleaner and reassemble.

While you've got that out, take a look and see if someone has hacked at the cables around there - it's possible that this is where the trailer wires attach to and something might not be right in that area. You might also try the hazard lights and brake lights while the left hand unit is disconnected, just to see if the right hand side starts behaving and check that the reversing circuit isn't activated.

If it's still glitchy, you might check that the earth in the trailer plug is sound (ie good electrical connection to the chassis). This is a common pain. Let's see where you are after that.

 

[UP04 WRK]

Thank you... I will definitely be trying this. Any help is truly appreciated!

 

[tweak'e]

as above, very common problem with all vehicles is how trailer wires are tapped in and the earth.
a poor earth can mean not enough current flows and makes the indicators flash fast like you have a blown bulb. it also can mean one set of lights can go to earth via another set of lights and cause all sorts of weird stuff.

 

[UP04 WRK]

Thank you... appreciate it. the only earth I understand is the trailer control module it goes to the chassis. Re-did that, all shiny still no joy. on it goes! tow bar electrics seem like they go back to the neg on battery..? I am lost

 

[Old.Tony]

Thank you... appreciate it. the only earth I understand is the trailer control module it goes to the chassis. Re-did that, all shiny still no joy. on it goes! tow bar electrics seem like they go back to the neg on battery..? I am lost

Running decent cabling from the battery to the trailer plug is just good management. The standard electrics in the car aren't up to the loads of a trailer. Electric brakes pull about 3-3.5A per wheel (so up to 14A for a dual axle). Running a 180W 3-way fridge draws 15A. All this on cabling you wouldn't run 10A through continuously, yet here we are heading to Uluru again ...

The next thing I'd look at is the condition of the tail light bulbs. My tail light went funny when a bit of corrosion took hold in the left hand reversing light bulb socket. Made the thing do silly stuff - dim lights, wrong lights blinking etc.

 

[UP04 WRK]

Thank you... it hurt my head too much, I checked everything, I am sure!?! its in the garage today, let's see??

 

[Chapster]

Sounds like a dodgy earth to me as others have mentioned. Sometimes the issue is not the earth's connection but an inferior gauge cable under load. Not hard to temporarily add an additional wire and see if that sorts your problem. If it does, upgrade.