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Discussion Starter #1
Folks, assist me in finding the culprit.

Fuse F 11 next to the battery keeps popping. Not immediately. First it popped, got replaced and popped after about a week. The popped after a day, then popped after 10 minutes (discounting time when the engine isn't running).

I bought a few now and I want to systematically disconnect each item that I have identified linked to this fuse. But some, like the MAF are said to be drawing too little power to be capable of popping this fuse.

The other culprits require jacking the car and it is so low I can't get the jack to the jacking point. Still need to figure this out.

But, if someone can provide info that will immediately rule out culprits, please shout.

Car is Q4 3.2 159 auto.
 

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Folks, assist me in finding the culprit.



Fuse F 11 next to the battery keeps popping. Not immediately. First it popped, got replaced and popped after about a week. The popped after a day, then popped after 10 minutes (discounting time when the engine isn't running).



I bought a few now and I want to systematically disconnect each item that I have identified linked to this fuse. But some, like the MAF are said to be drawing too little power to be capable of popping this fuse.



The other culprits require jacking the car and it is so low I can't get the jack to the jacking point. Still need to figure this out.



But, if someone can provide info that will immediately rule out culprits, please shout.



Car is Q4 3.2 159 auto.
Electronic injection sundry secondary services, it says.

http://www.autogenius.info/alfa-romeo-159-2005-2011-bezpieczniki-schemat/amp/
 

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Some of the lambda probes heaters might be the cause. Try to disconnect them (the probes) one by one to localize the faulty one. The engine can run without them, no matter, that errors will be logged.

Check also the wiring to the variators solenoids - especially for damaged isolation.
 

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..... But some, like the MAF are said to be drawing too little power to be capable of popping this fuse.
....
Unless f.i. the MAF is defective of course, and drawing too much current, kind of the purpose for a fuse ;)
 

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Discussion Starter #6
Disconnected MAF, fuse popped in less than 5 minutes.

Solenoid cables look fine visually, I checked all cabling and earth points (the great wiggle test).

Cabling to the three injectors also looks fine (the other three are a schlep to get to, maybe a mouse got in there and started munching).

Lambdas are the next usual suspect, but that would be a weekend job and I still need to figure a way to get the jack under the belly. I wonder if I can use the OEM jack, lift the car from one side, then push the jack under, align and lift, then replace the OEM jack with jack stands.

Anyways, if it is the lambdas, will be revealed on Saturday.
 

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install amp-meter in series with the fuse (you need to work out the way how to install it; or use actually volt-meter across fuse at mV range as alternative or naybe clamp type anp meter could be attached around wire of f11 circuit) and using schematics out of eLearn try to locate at which loom the current flows - mean you may be disconnecting various suspected things before fuse blows to speed up search while monitoring the current at amp meter (or voltage drop across fuse itself).
 

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Discussion Starter #8
Epsonix, Each part has multiple wires, I don't know which wire does what and which is active when. Seems simpler for me to just disconnect the part and see if pop goes the fuse.

There are instances where the ECU itself is the source of the fault. I sure hope this is not the case. Pricey.

install amp-meter in series with the fuse (you need to work out the way how to install it; or use actually volt-meter across fuse at mV range as alternative or naybe clamp type anp meter could be attached around wire of f11 circuit) and using schematics out of eLearn try to locate at which loom the current flows - mean you may be disconnecting various suspected things before fuse blows to speed up search while monitoring the current at amp meter (or voltage drop across fuse itself).
 

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Remove and clean the MAF sensor with a spray of iso-propyl
Alcohol on the resistor wire. Also spray into the vent holes at the bottom of the plastic surround. Use a cotton bud or two soaked in glass cleaner to clean off the angled mirror only, no need to touch anything else. Allow to dissipate and refit.
Oil and dirt on the resistor wire increase current and pop goes the fuse!
 

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Discussion Starter #10
Not sure though, the fuse popped while the MAF was disconnected.

Today I disconnected one of the O2 cables and started the car while jacked. ran fine for a long time. restarted a few time no issues. then I reconnected the wire, ran fine again.

Then I shut down, replace the cable cover, remove jack stands, lower the car and started it and immediately pop goes the fuse.

Now I am thinking the cable cover is pinching the wire. Will test this on Friday, after that I am going to an autoelectrician.

Remove and clean the MAF sensor with a spray of iso-propyl
Alcohol on the resistor wire. Also spray into the vent holes at the bottom of the plastic surround. Use a cotton bud or two soaked in glass cleaner to clean off the angled mirror only, no need to touch anything else. Allow to dissipate and refit.
Oil and dirt on the resistor wire increase current and pop goes the fuse!
 

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Check your wires leading to O2 sensors after cats. They both lead over heat shield around propshaft. Like on video above on mine Brera the heat shield got close enough to the propshaft to start rubbing and pinched the wire. Just so it is written in plane words for the next guy skimming through. :wink_org:
 

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Discussion Starter #13
Thanks Peter. The CEL also disappeared, by itself.

First symptom was limp mode.

Car is back to its normal best behaviour.
 
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