Electrical problem

[Gromit]

Evening all,

I've got a bit of an intermittent fault on the sister's 110, which I obviously can't reproduce now

Anyway, Lights off or parks and the indicators work fine.

With dips on, the front and rear OS indicators glow dimly. OS indicator doesn't work. NS is fine. I think that the main OS light does not light fully.

First thought was the column switch, but if there was a crossover from the lights to the indicator at the switch, I thought it would cause the indicator to flash rather than just glow?

Am going to pull the switch out and start shorting the feeds to see if I can reproduce it.

Any ideas? I guess as the fault affects one side of the truck, the problem is before the fusebox.

Cheers,

[Fatboy]

Gromit,

I'd startt working on confirming the earths are okay before playing with supply +ve's as the earths are more likely to corrode and become ineffective.

Its also easier to test. Remove a rear light cover and fit a length of wire to a good earth point, then touch it on the outside of the bulb (metal part obviously). If the brightness changes intensity, you then know that you need to take the unit out and clean the body where the earth screw goes. Before putting it all back together, pop a tad of grease onto the bare metal to prevent future corrosion.

Good luck.

[LandyManLuke]

Earth problem for sure, usually is when one circuit starts interfering with another.

[Gromit]

Yes, was going to look at the earths too.

On this:

Remove a rear light cover and fit a length of wire to a good earth point

As both the front and rear indicator show the fault, am I right in deducing that the fault has to be before the fusebox?

(As the fault is completely random at the moment, just trying to narrow down my choices when the fault does arise)

[LandyManLuke]

It's highly likely both earths, front and rear, are bad. they often are.

[Gromit]

It's highly likely both earths, front and rear, are bad. they often are.

Rear lights and indicators are new 2 weeks ago, so I'm confident they are ok.

Was just wondering if my logic was correct

[Guest diesel_jim]

Rear lights and indicators are new 2 weeks ago, so I'm confident they are ok.

Was just wondering if my logic was correct

But both front and rear lights share the same earth circuit i think,.... so one of them could have "died" a while back and you wouldn't have noticed any difference, but now the "other" one has gone duff, you've got the problems.

definately earth related though.

[TheRecklessEngineer]

It is the earth for the OS headlight cluster. It is earthing through the OS front indicator which of course is connected to the back.

[landmannnn]

I had an interesting one a few years ago.

I had replaced a rear sidelight bulb. (twin filament side and brake light)

A few weeks later one evening on a bit of a hill I turned the ignition off. The engine kept running even though I had taken the key out of the ignition.

Very confusing.

It turned out there was a short in bulb itself. Because it was dark I had got the lights on. With my foot on the brake the brake light circuit was taking 12v from the sidelight circuit and then powering the ignition.

A long winded way of saying that just because your light units are new does not mean they are working correctly.