Alfa Romeo Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
44 Posts
Discussion Starter #1
Hi, I have a 2008 159 1.9JTDm Lusso.

I have a recurrent problem with a fuse blowing. It's a 7.5A one unhelpfully labelled as services. When it blows it knocks out the Cruise Control and the reversing lights. The parking sensors still work but they have to be activiated manually, it appears that the reverse light switch is knocked out as well.

In addition, the following error codes appear: P0504 - Brake pedal switch, P0101 - Air flow meter signal, P0111 - Air flow meter air temperature signal. Replacing the fuse will allow me to clear the codes but then in 1/2 hour or maybe 5 days (!?!) the fuse will blow and the codes are back.

I have been told that this fuse also deals with the 'water in fuel' sensor in the fuel filter. I have systematically disconnected each of the affected components, replaced the fuse and then waited to see if the problem re-occurs. It always does. The only one that seems odd is the brake switch, when I disconnect that I get a whole new load of errors relating to associated switch functions. So the fuse blowing is not directly affecting the switch but possibly the Cruise Control module? Or does the switch have different connections for the different modules it connects to?

Anyway, I'm at a bit of a loss. Can anyone suggest a way forward please?
 

·
Registered
Joined
·
1 Posts
I have the exact same problem... can't understand the root of it. I have been putting 20amp fuse, and it's still blowing.
 

·
Registered
Joined
·
2,888 Posts
I have the exact same problem... can't understand the root of it. I have been putting 20amp fuse, and it's still blowing.
Oh Dear - Don't go putting bigger fuses in to try and overcome a problem, your just asking for trouble.
There's a reson it's a 7.5 amp and that's to make the cheapest component sacrificial (the fuse) and to protect more expensive components - fitting bigger fuses can lead to damaging or burning out much more expensive components......Don't do it :judge:
 

·
Registered
Joined
·
565 Posts
I'd always suspect the brake pedal switch in these circumstances. For a tenner and five minutes of your time to fit I'd change it as a service item anyway.
 

·
Registered
Joined
·
44 Posts
Discussion Starter #5
Well, the problem is fixed. In addition to that fuse blowing I had a 10A fuse in the engine bay fuse box blow. Fuse 17. This knocks out the engine management, and of course, the case won't start. You get an error saying Vehicle Protection System failed and lots of weird lights etc.

So I took it to the dealer. Turns out it was the wiring loom for the engine. Lots of damaged wires in there. Apparently some of the fixings had been removed at some point (I think maybe before I bought the car) and over time the vibration has knackered the loom.

Anyway, new loom and we're back in business. No engine codes, no elm, everything works properly. Sorted.
 

·
Registered
Joined
·
326 Posts
Well, the problem is fixed. In addition to that fuse blowing I had a 10A fuse in the engine bay fuse box blow. Fuse 17. This knocks out the engine management, and of course, the case won't start. You get an error saying Vehicle Protection System failed and lots of weird lights etc.

So I took it to the dealer. Turns out it was the wiring loom for the engine. Lots of damaged wires in there. Apparently some of the fixings had been removed at some point (I think maybe before I bought the car) and over time the vibration has knackered the loom.

Anyway, new loom and we're back in business. No engine codes, no elm, everything works properly. Sorted.
How much was your loom to buy and install please?

Sent from my SM-G925F using Tapatalk
 

·
Registered
Joined
·
44 Posts
Discussion Starter #7
Hi, I had some other work done at the same time but I think the loom was £600 all in, parts and fitting. It was a main dealer job. I haven't had any electrical issues since.
 

·
Registered
Joined
·
1 Posts
solution

new reply to an old topic

BUT

I was having the same issue, turned out to be the loom which runs through the boot from the body to the tailgate, water corrosion i suspect

No nsr light cluster and pop switch, also fob switch was blowing the 15a fuse for the boot mech (f38)


Strip out the back seats, send a gangly apprentice in to open the boot (i snapped the manual opening lock)

repaired 4 wires withing the rubber boot, all faults cleared themselves


alot runs via fuse f35, a week ive owned an alfa and hated it last night

4 hours, some swearing, sweating and patience cost me nothing to fix.

feel free to DM me if anybody else experiences these issues il be happy to help
 
1 - 8 of 8 Posts
Top