Hi, my names Ollie and our family has owned a Fabia 1 for years which has been great, but now I've been asked to help a friend out during our isolation, Isolation wise its OK as we chucked each other keys and they've gone off to help a friend who's had a house fire! complicated or what, anyway I digress.

They have a  Fabia 2 1.4 16v, again its been generally good, but I have had to help them with a few wiring issues around the central locking and doors in the past.

Today its got a dead battery and the alternator isn't charging, I can manually excite the alternator through the blue wire with a test light so the alternators working. question is what fires this blue wire normally? and what does the brown wire do! and for that matter why doesn't the dash illuminate any charge warning light!

 

Anyone got experience or wiring diagram for one of these please? I'm expecting to find a broken wire somewhere but would be good to check the other end out first, wherever that is......

 

Many thanks

 

Ollie

 

 

The charge warning light not illuminating at ignition-on is a well-known symptom of a broken blue alternator excitation wire (on mk1s at least). There's no direct connection between the two as the blue wire finishes/starts at the onboard supply control unit above the accelerator pedal, but the cluster seems to behave as if there is (as there used to be in olden days).

 

Look for a bracket on the front of the gearbox with a few connector pairs on it.  See if there's a two-way pair with blue and brown wires going into one side. blue and a different colour coming out the other.  On mk1 Fabias this is where the wires usually break, not sure if mk2's have the same bracket/connectors. Very common failure on the mk1.

 

The brown wire is feedback from alternator to engine ECU, telling the ECU what proportion of its possible current output it is producing at any one time.

 

What year is the car? There are different wiring diagrams depending on when manufactured. Also the engine code is very useful if you know it or can find it, as the wiring diagrams are segmented by this.  Look for a sticker on the boot floor, or one on the upper cambelt cover, this info is on both.

 

 

Edited 27 March, 20206 yr by Wino

Thanks for the info, very quick! I'll look for wiring breaks in the day-light tomorrow. Cant read the sticker in the boot, its dissolved courtesy of a water leak..... used to have access to autodata courtesy of work, but they haven't paid the subscription so cant get anything that way. If there are any diagrams online that might give me  starting point.

 

Thanks again

 

Ollie

I don't know of free-to-use diagrams for mk2s online, but you can download them for a 7-Euro-plus-tax fee from a service called erWin. They are copyrighted documents so anything you do find online will be hacked/infringed.  That's not to say there isn't any though.

 

Happy to tell you what goes where once you find the engine code and tell me the year though.  I'll get on Wikipedia and see what possible engine codes exist for a mk2 Fabia 1.4/16V.

If you know the BHP output that may be enough to pin it down?