Technical Diesel Electrical help!!!!!

[jonsey324]

Good evening,

I have just fitted some laser lamps into the grill of my Ducato based Adria Motorhome 2021.

All worked fine when test fitted the other day, went to fit for the last time this evening before final fix, tried the new light nothing.

Have take the live feed from the fuse board under the bonnet and negative to the chassis.

Tested the live i took from the fuse board under the bonnet and have no power.

Checked the fuses on the battery in the cab, all had 12v power

Any ideas what possibly I could have done to not have power at the fuse board, possible solutions

 

[The Panda Nut]

Maybe blown a bigger main fuse the that box. Look at all the big fuses 30A and above. Possibly in a secondary fuse box. Or have you had the battery off and missed a wire off?

I wired mine by taking a feed off the side lights and using it as relay-switch feed. Using a fused relay does help isolate your wiring from the vehicle systems pretty well totally.

 

[Communicator]

Good evening,

I have just fitted some laser lamps into the grill of my Ducato based Adria Motorhome 2021.

All worked fine when test fitted the other day, went to fit for the last time this evening before final fix, tried the new light nothing.

Have take the live feed from the fuse board under the bonnet and negative to the chassis.

Tested the live i took from the fuse board under the bonnet and have no power.

Checked the fuses on the battery in the cab, all had 12v power

Any ideas what possibly I could have done to not have power at the fuse board, possible solutions

I do not have details of the x290 wiring, but there will be many similarities with earlier models from which it has evolved.

You have not made it clear whether you have a total loss of power to the engine bay fusebox, in which case you will not be able to crank the engine, or is the supply missing only from the fuse that you connected to?

Which fuse did you connect to?

You mention checking 12V on the fuses at the starter battery in the cab. Typically the only relevant fuse at that location is F70, the orange coloured,150A mega fuse, which has 8mm studs.

How was it tested?

 

[Anthony489]

Hi. I only have data for earlier vans, but I doubt if the Fiat way of doing things changed all that much. See attached marked up diagrams and treat them as a guide only. They don't show everything. Next to the vehicle battery positive terminal there are a handful of high current fuses. One of these (F71, 80 Amps) supplies all the current to the under dashboard fusebox via a thick red wire. Another (F70, 150 Amps) supplies all the current to the under bonnet fuse box, again via a thick red wire. These fuses will only blow with a really substantial current, e.g. the thick cable has a dead short to the chassis, so I doubt that is your problem.

I suggest your re-check your wiring. You can test blade fuses visually for a break, but life will be much easier if you get a cheap multimeter and use it on the ohms range to test them out of circuit.

One way to add accessories is with a special piggy back fuse. It has a "side branch" wire with its own floating fuse holder just for the new accessory, such as a dashcam or in your case lights. The fuse replaces one in an existing circuit. You can place it either way round, so that your accessory is either fed from the upstream or downstream side of the original fuse. Normally the upstream side would be used.

 

[Brassnadz]

Good evening,

I have just fitted some laser lamps into the grill of my Ducato based Adria Motorhome 2021.

All worked fine when test fitted the other day, went to fit for the last time this evening before final fix, tried the new light nothing.

Have take the live feed from the fuse board under the bonnet and negative to the chassis.

Tested the live i took from the fuse board under the bonnet and have no power.

Checked the fuses on the battery in the cab, all had 12v power

Any ideas what possibly I could have done to not have power at the fuse board, possible solutions

Get a good 3' length of wire like speaker wire n ground one end thoroughly n use other end as check replacement for ground wires in ur system. In other words check grounds thoroughly first as this easiest n most common fault. No pun (common) intended.