Technical NO Main Beam lights

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Technical NO Main Beam lights

Daveof49

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Problems seems to be coming quick and fast with my 1.9 8v Croma.

Having just had to fork out nearly £600 on a new BCU unit my main beam lights have gone on the blink. The blue main beam light on the dashboard comes on when the stalk is operated but neither of the two main beams light up. All other lights are ok.

My garage have suggested that it could be a faulty relay. Does anyone know which relay controls the main beam light. Thought I would check this before taking it to the garage.
 
I am not sure which relay it is without looking at the wiring diagram, it sounds logical though to suspect the relay as they have both stopped working at once.
 
Looking at the diagrams it appears to be Relay T2 situated in the engine bay to the right of the battery (engine compartment junction unit B001).

Description from EPER

The vehicle is equipped with two high beams in the headlamps.
The high beams are activated by operating the left steering wheel stalk:
- when the low beams are on, by pulling the lever toward the steering wheel (2nd unstable position);
- in flashing mode, irrespective of wheel position, by pulling the lever towards the steering wheel (1st unstable position);
The high beam activation relay is controlled by the Body Computer The relay is excited by enablement signals received when the key is inserted into the ignition and turned ON (INT from the steering lock control unit) and a specific control signal from the steering wheel stalk unit.
Activation/deactivation information is sent via the CAN network: in this way, the high beam warning light is activated on the control panel.

Functional Description:

talk unit H005 sends two earth signals, depending on left stalk selection mode, to the Body Computer M001:
- from pin 4 of connector B it sends pin 33 of connector G of the Body Computer a light flasher activation signal (1st unstable position);
- from pin 3 of connector B it sends pin 4 of connector I of the Body Computer a high beam activation signal (2nd unstable position);
Body Computer M001 (pin 9 of connector A) controls the power supply to the high beams by sending an earth signal to engine compartment junction unit B001 (pin 12 of connector A) that excites relay T2: this supplies the high beams of headlams F010 (left) and F011 (right). Each of the two lines is protected by a fuse in control unit B001:
- F15 for the left headlamp, from pin 25 connector A;
- F14 for the right headlamp, from pin 22 connector A.
Via the CAN line, Body Computer M001 (pin 5 and 6 of connector I) connects to instrument panel E050 (pins 3 and 4 of connector A), to control the high beam warning light.

Sorry cant post diagram as i'm having problems attaching the SVG file.
 
Wow, thats some reply PaulD78.:worship:
A thought - Would you know if this type of fault would have been discovered by Fiat Ecuscan as the BCU is involved ?

Found the relay its the third black one back front thr front end of the car. (Relay block in engine compartment by the battery.)

I found it by jiggling each relay with the ignition on and the main beam on and the engine running. It appears that the small two contacts (the coil side of the relay) were not making a good contact so I have very slightly bent these two contacts on the relay and pushed it into place. It actually felt a better fit and the lights are now working. So I will now have to see if they keep working.:)
 
Thought it was too good to be true. The situation with my main beam headlights still persists. Took it into the garage who have diagnosed a faulty fuse/relay box. (the one next to the battery). £ 155 plus vat to replace £75 for the box the rest for labour. Told them not to bother and I will sort it out myself !

Any one got a spare fuse box you want to sell ? !!

Anyone stripped the fuse box and repaired?
 
Thats bad news,i dont think the 75quid for a new fusebox is to bad though.

You dont think this is down to high resistance somewere in the circuit and causing the terminals in the fusebox to open up due to getting hot?I had the same problem with one of my service vans not long ago.
 
Buster - No, the garage reckon that one of the connectors to the main beam relay is broken or has a dry solder joint. This would seem to be the case because if you press down on the relay the main beam work - release the pressure and they don't.

They have also said that the units are encased in a resin to waterproof them so you cannot get access to re solder.

I have thought about removing the unit to see if I could grind some of the resin away in order to carry out a repair somehow. Anyone tried this?

I am trying to source a fusebox at the moment.
 
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