[nomadfox]

Hello alfa owners,

I recently bought a second hand (2006) 147 jtd 1.9 with a lot of kilometers (250 000km),
it had a clutch problem that I'm taking care of today, installing a new kit,
I suspect electrical problems because when I turn the key, the first 10 seconds I hear noises on the speakers (sounds like cockroaches running inside the dashboard) and have too many lights on and messages :

• ABS
• Airbag
• VDC (when going fast enough)
• Something that looks like a turbo
• "Avarie système contrôle moteur" (it's configured in French but I'm pretty sure this is caused by a faulty injector)
• Speedo stays at 0

The weirdest thing is when I accelerate too hard, as long as I'm holding the accelerator, all the lights go off and speedo shows the right speed but as soon as I lower the throttle even just a bit, everything comes back on and speedo falls to 0 again.

What do you suggest I try ? what should I check ?

Thanks in advance.

 

[nomadfox]

I found this thread : https://www.alfaowner.com/threads/strange-electrical-faults-fixed.1176693/
Will try this as soon as I get the car back from the repair shop (getting clutch replaced) and will tell you what happens.
This might be the right path

 

[nomadfox]

update on the ABS issue, I took the car to an auto electrician, he disconnected the abs control unit and tested the power pins, it turns out the negative or ground pin is not "working", either disconnected from the other side or cut halfway, now I'm looking for a wiring diagram to know where that cable goes to and do a continuity test.

 

[paul.o]

Hopefully, some will be able to help you soon.

 

[R.T.]

Can’t give specific advice but I’m sure Fruity (in your link) is right. With so many faults it’s likely to be bad earths. The ABS earth fault found certainly suggests this, though there may be supply problems as well. I would find and work methodically through the body and engine earths, unbolt, clean and reassemble. Then coat with Waxoil etc.

The main earths on the 156 are on the chassis rails behind and below the headlights, accessible from underneath; might be similar on the 147?

I’m not at all sure but it’s possible that the ecu disables the air con when you go to full throttle, to put all available power into the wheels. This might explain why the fault is throttle dependent, but I would still start with the earths then move on to the supply side if that doesn’t sort it.

 

[nomadfox]

Thank you for the reply Paul and R.T,

The main earths on the 156 are on the chassis rails behind and below the headlights, accessible from underneath; might be similar on the 147?

I don't think they are, I checked on my brother's 156 (TS not jtd) and it's different,
From Elearn I found that the ABS earth is linked to C12 connection, I've been looking for that connection for two whole days but couldn't find it

I can see it on the schematic but can't find it IRL.

I tried putting an additionnal cable going from battery negative to C50, resistance between battery and C50 connector was 9 ohm and went 0 after the cable was added, still no change (cable taken out for safety).

Now I will take out the aircon fuse too and maybe disconnect the bose amplifier, hoping this gives us some more information.

Thank you for your help.

 

[nomadfox]

Now I will take out the aircon fuse too and maybe disconnect the bose amplifier, hoping this gives us some more information.

Disconnecting the aircon fuse (not radio) made the noise on the speakers (when turning the key) disappear, but no other change, however I still hear noises when reconnecting the battery.
keeping the fuse out for now, especially since I noticed the car started in a single starter kick with this fuse out, maybe just a coincidence maybe not, we'll know for sure tomorrow morning.

Speaking of supply, the alternator gives 14.xx volts, which appears good, but off, battery gives 12.20 or 12.30 after sitting through the night, should I change it ?

 

[R.T.]

The battery needs to be above 14V for many hours (ie: fully charged) before that becomes a valid test, but if it was then yes, change it. (You are saying you had it disconnected overnight, to stop the car draining it?)

I tried searching for 147 earth positions, have a look here: Earth points

Posts 3 and 4. Unfortunately it doesn’t say which car, but that’s all I’ve found so far.