# Fiat 2.8 JTD - Short circuit on Indicators/Hazard lights



## SueandRoger (Apr 14, 2008)

I have a short circuit on my indicator circuit as the Fuse (No 53) keeps blowing as soon as I put a new Fuse in the Fuse block! This happens even when the ignition is off which I 'presume' this is because the Hazard light circuit is always 'Live'?

I have limited knowledge on the use of a Multimeter but have set it to 'Bell Mode' and put it between the 'Out Terminal' of where the Fuse should be in the Fuse Block and an Earth and the Bell sounds to show that there is a short to Earth somewhere on the Positive side; Is this correct?

I have checked and cleaned the Rear indicator Bulbs and they appear to be good but have not yet had time to check those at the Side and Front. If I find no fault in those, do I take it that a wire somewhere must have 'Worn' and is touching part of the Chassis and if this is the case, how do I locate the fault; Trace every wire in the Indicator circuit, which will be difficult, or is there a better/easier solution? Or, could the fault be in the Indicator Relay which I 'think' is in the fuse box under the bonnet but if so, which Relay is it as there appears to be three or four which look the same!

Any ideas will be very much appreciated and I will act on them as soon as possible; I am however informed by 'Her who must be 'obeyed', that I have far more important duties over the next few days! Waste of time Retiring me thinks if I can't do what I want


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## TR5 (Jun 6, 2007)

Putting a meter across a live point to earth is not proving a fault, but proving the terminal is in fact 'live'. You are creating a circuit.

The short, causing the fuse to blow is more likely to be one of the light fittings, with either water or corrosion causing the problem.
It could also be the hazard or indicator switch, or the dash light.

As it blows immediately you put a fuse in I would suggest looking from the fuse board to the hazard and indicator switch, as the supply would /should not be reaching the indicator light units, unless of course you have the hazard switch on.

Process of elimination I'm afraid.

Edited: Sorry, just read it again and you tested from the load side of the fuse, so YOU are correct, there appears to be a short to earth, somewhere up to the hazard or indicator switch.


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## SueandRoger (Apr 14, 2008)

Thanks TR5. When you say "somewhere up to the hazard or indicator switch" I presume you mean starting from the Indicator lamps?

I am not sure if the Hazard light switch is on or not as the fuse blows as soon as I insert it whatever position the switch is in but as the switch does not even light up, I can not be sure if it is the hazard switch that is causing the problem!

I have checked and cleaning the 4 rear indicators and have not found any signs of a short yet (Could it be a fault within a bulb itself?) and will start checking the remainder over the next couple of days if I get chance: not sure how I check the switch gear though! Do you know which relay it is?


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## 747 (Oct 2, 2009)

Over the years, I have twice had a problem with indicators. Both times the problem has been at the steering wheel.

Once was the indicator stalk and the other was a short on the unit that controls all operations (ie, wipers, indicators, lights etc on a Peugeot car). The second one was an expensive fault to repair, it meant a new unit at £240 (from memory) plus labour.

I would advise seeing an auto electrician if you cannot find anything obvious to the eye.


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## TR5 (Jun 6, 2007)

If the switches (indicator and hazard) are off, then the fault will probably lie between the fuseboard and the switches, as there will be no live feed to the indicators to cause the fuse to blow.


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## SueandRoger (Apr 14, 2008)

TR5 said:


> If the switches (indicator and hazard) are off, then the fault will probably lie between the fuseboard and the switches, as there will be no live feed to the indicators to cause the fuse to blow.


I now have the time to devote to finding where the problem is but not sure how I go about tracing the wiring from the fuse board to the indicator switch or Hazard switch as they are in a loom or, do you think the problem is more likely to be the switch gear itself? I intend to unplug the loom from the Indicator/wiper switch tomorrow and see what that does!

I don't know if this is means anything but I am not getting any sign of an earth anymore with the ignition on or off but with it on, I do get a fluctuating reading of 4 - 5 volts between the load side of the fuse and earth!

I was going to book the van in to my local Fiat dealer next week but not sure if I would be better off trying to find a dedicated Auto Electrician in the Hampshire area or am I doing Fiat an injustice?

Edited: To add that lights and wipers are working correctly!


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