No Rear Brake lights !

[luigi59]

Hi

We have had lovely summer so far touring around UK, but now I am so fed up .This weekend I thought I give our Fiat Ducato Carioca Living 22 Motorhome 2004 a good clean up and polish like we do and a check over everything was nearly complete when I notice the roof brake warning light had only two bulbs working. So I got up to see which bulbs needed replacing I released the lamp first from the recess .Then double checked the rear brake lamps were working before fully removing the roof brake warning light, but as we tried them again they worked then went off and they have not worked since we have checked all the fuses and relays without no avail. I have been advised by a neighbour to get an auto electrician in but our concern is this could cost a lot of money any help or advice would be very much appreciated. :-( *-) :-( :'(

[Guest Joe90]

The very first thing to do is get a multimeter and check that 12 volts is getting up to the unit with the brake pedal depressed, if it is then the light unit is likely to be the problem,possibly just a bit of corrosion where the wiring attaches, but check as I say for voltage getting up there in the first place before you suspect problems with fuses or relays or wiring further into the loom.

[pepe63xnotuse]

...maybe you've just disturbed/broke/yanked the wires out, further down the run..?

 

Can you see where they exit at the bottom, under the van?..if so, see if there's power getting to that point?(maybe even drop a new wire down?)

 

[Tracker]

Do the lower brake lights work?

 

If it worked before you touched it and now does not first suspect is something you have done.

 

The most likely cause of light failure in these locations is firstly a poor or broken earth return and next a broken , missing or damaged contact in the bulb holder.

 

A simple multimeter can be used to check both voltages and bulb continuity and if you don't have one they are inexpensive on Amazon and can save you a fortune if you understand how to use one.

 

Apologies for stating the obvious but brakes lights only work with the engine switched on?

 

If you don't then a good auto electrician might well be the best option.

[Brian Kirby]

All the brake lights must work together, so there will only be one point of supply for them. If the brake lights in the rear lamp clusters are both working, then the supply is OK.

 

What you then need to find is where/how the supply to the high level light originates. I would expect this to come from either of two places. First, from connections on the back of one or other of the two rear lamp clusters, or second, from a common connection feeding both the rear lamp clusters and the high level lamp.

 

There is often a connection block at the rear of the base vehicle chassis to which the converter connects his rear, brake, reversing, and indicator feeds. It may be that the high level lamp has been taken direct from this point, or from a further connection block that the converter has installed nearer to the rear of the van.

 

However, because it is simple, I would expect the high level lamp wiring to originate from (or simply pass through) or or other of the rear lamp clusters.

 

The main problem is that there is no standardisation of practise among converters, or even within any one converter's model ranges. Your only remedy seems to be to trace the wiring to the rear lamp clusters, and then look for the wire (probably two, as I would expect the return also to be wired - commonly black insulation), that feeds a brake light lampholder, but then goes on elsewhere. Once you find this, look to see if there is any corrosion, or more probably if the connector is loose or the wiring has pulled free.

 

I suspect that since the high level lamp was working, albeit with some lamps out, all that has happened, as suggested above, is that a connector has simply become detached as you removed the high level lamp.

 

However, to avoid making matters worse, make sure you tie something to the wires feeding the high level lamp before you disturb anything further - a piece of string will do - so that feed can't suddenly disappear into some inaccessible void behind the high level lamp. Then just stick the other end of the string to the back wall of the van with tape - to make sure it can't follow the wire into the void! :-)

[Guest Joe90]

The very first thing to do is get a multimeter and check that 12 volts is getting up to the unit with the brake pedal depressed, if it is then the light unit is likely to be the problem,possibly just a bit of corrosion where the wiring attaches, but check as I say for voltage getting up there in the first place before you suspect problems with fuses or relays or wiring further into the loom.

 

 

Oops I've already said that at the top of the thread ! !

[747]

There is a good chance that it could be a poor earth and you have disturbed it.

 

The easiest way to check is to get a length of wire and connect it to a good earth and the earth fitting on the lights and then try the lights.

 

I had a similar problem with my high level marker lights. The voltage does drop significantly over a long cable run. At one of my fittings it was down to 10 volts and the fitting was earthed into the Aluminium sheeting of the van panel. I had to run a separate earth wire from that fitting across to its mate on the other side of the van which did have an earth wire.