Indicator/ Hazard blinker relay/ alarm | Starts to blink without notice

dieselfan

A2OC Donor
Ms dieselfan's 1.4TDI 2004 BHC do not behave as one could wish...
Last months hazard light has now and then started to flash during the night, with an empty battery as result when she enter the car 07.00 to go to work..
One touch of hazard switch stop hazard blinking. Until it suddenly starts to blink again, typically during the night...

This car is delivered with alarm, but the horn/sound was disconnected by last owner.
I have tested the door mounted microswitches
Instrument cluster and ECU is from an AMF 2002, and there are some functionalities that is not working (engine warning light and limp mode first time one pass 2500 revs, and remote lock with key/keys)
VCDS scan identify intermittent cooler fan controller issue and key issue. These are old and I assume they are not related to the hazard blink since that problem has appeared now , while the other fault codes are one year old.

I have changed four indicator/hazard relays over the last 12 years on our other A2's, so I have some experience with that relay, but this time I have no issue with the indicator functionality, which I find a bit weird...

I have changed the relay and hazard switch to used ones and then the car was ok for three days so I thought I had found the defect... then it started to hazard blink again... Used parts came from a donor car that I do not know in detail so that's not ideal...
My hands are crippled due to arthritis so I really struggle to get the indicator relay out of its bracket, so from now I wrap the relay in cell foam and put it in the ashtray... so now it is easy to change it.

I hope someone can come up with a smart way to proceed.

Hazard blinking do still start to flash on random, even once while driving...but most often during the night with locked doors. 6-8 times per week.

  • Should I disable the alarm? if yes, how do I do it?
  • Should I buy new both blinker relay and hazard switch new and change them?
  • What should I trouble search ?
Thanks in advance
dieselfan
 

Weetank2

Member
Ms dieselfan's 1.4TDI 2004 BHC do not behave as one could wish...
Last months hazard light has now and then started to flash during the night, with an empty battery as result when she enter the car 07.00 to go to work..
One touch of hazard switch stop hazard blinking. Until it suddenly starts to blink again, typically during the night...

This car is delivered with alarm, but the horn/sound was disconnected by last owner.
I have tested the door mounted microswitches
Instrument cluster and ECU is from an AMF 2002, and there are some functionalities that is not working (engine warning light and limp mode first time one pass 2500 revs, and remote lock with key/keys)
VCDS scan identify intermittent cooler fan controller issue and key issue. These are old and I assume they are not related to the hazard blink since that problem has appeared now , while the other fault codes are one year old.

I have changed four indicator/hazard relays over the last 12 years on our other A2's, so I have some experience with that relay, but this time I have no issue with the indicator functionality, which I find a bit weird...

I have changed the relay and hazard switch to used ones and then the car was ok for three days so I thought I had found the defect... then it started to hazard blink again... Used parts came from a donor car that I do not know in detail so that's not ideal...
My hands are crippled due to arthritis so I really struggle to get the indicator relay out of its bracket, so from now I wrap the relay in cell foam and put it in the ashtray... so now it is easy to change it.

I hope someone can come up with a smart way to proceed.

Hazard blinking do still start to flash on random, even once while driving...but most often during the night with locked doors. 6-8 times per week.

  • Should I disable the alarm? if yes, how do I do it?
  • Should I buy new both blinker relay and hazard switch new and change them?
  • What should I trouble search ?
Thanks in advance
dieselfan
Perhaps start by checking the battery , thinking if in a poor state alarm possibly upset, exacerbated by cold
Is it recent and decent quality , is the alternator charging well
Is the car garaged overnight or subject to Norwegian cold nights
How long is your wifes commute , subject to high demand, heating lights etc , is the car getting a chance to charge
 

dieselfan

A2OC Donor
Thanks @Weetank2 - her A2 is equipped with DEFA 230V onboard battery charger, cabin heater and engine heater.
It is unfortunately parked outside with a one year old Varta 75Ah battery.
Alternator is supplying 14.34V with lights on and fan at 50% measured with my multimeter.
Cheers
dieselfan
 

audifan

A2OC Donor
One thing that is quick and easy to check is the microswitch on the service flap. If this is set wrong the flap is still closed but enough play in the catch to let the switch make contact. The switch can also get knocked out of its mount which again makes the switch operate too early. So make sure the switch is mounted securely, that the flap is closed and locked correctly, lock the car then gently flex the service flap. If the hazards start to flash the microswitch has triggered the alarm. Quickest way to make sure the microswitch is depressed further is to glue a 3-4 mm thick washer, coin bit of plastic onto the square on the service flap that depresses the switch. The relay is a combined unit that operates the hazards and indicators.

The microswitch should have a rubber boot over the top of it but this can wear through or fall off, all effects the operation of the switch. They can also jam.
 
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kp 115

Member
Thanks @Weetank2 - her A2 is equipped with DEFA 230V onboard battery charger, cabin heater and engine heater.
It is unfortunately parked outside with a one year old Varta 75Ah battery.
Alternator is supplying 14.34V with lights on and fan at 50% measured with my multimeter.
Cheers
dieselfan
Hi diesel fan,
There is a coin cell arrangement within the alarm siren which have been known to fail
A6F9C170-BB9E-4B9C-B117-62057A2BC931.png

eBay item no: 391113370772
 
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dieselfan

A2OC Donor
One thing that is quick and easy to check is the microswitch on the service flap. If this is set wrong the flap is still closed but enough play in the catch to let the switch make contact. The switch can also get knocked out of its mount which again makes the switch operate too early. So make sure the switch is mounted securely, that the flap is closed and locked correctly, lock the car then gently flex the service flap. If the hazards start to flash the microswitch has triggered the alarm. Quickest way to make sure the microswitch is depressed further is to glue a 3-4 mm thick washer, coin bit of plastic onto the square on the service flap that depresses the switch. The relay is a combined unit that operates the hazards and indicators.

The microswitch should have a rubber boot over the top of it but this can wear through or fall off, all effects the operation of the switch. They can also jam.
Brilliant 👍
...you now guided me to perform my first Service Flap Microswitch test :) This was new to me and it was on time...
In one way good that ms's car passed, though I would be happy if it had failed and I could have a "case closed "

Many thanks
dieselfan
 

audifan

A2OC Donor
When you lock the car, exactly what does the red led on the drivers door do? Do the hazards flash as the car is locked?
 

dieselfan

A2OC Donor
When you lock the car, exactly what does the red led on the drivers door do? Do the hazards flash as the car is locked?
After 3s it starts to blink every 3rd s.

Harzard flash starts typically with locked doors (get locked 6-7pm and then goes off during the night.
It has also started to flash while driving...

I prefer permanent errors....

dieselfan
 

dieselfan

A2OC Donor
Hi diesel fan,
There is a coin cell arrangement within the alarm siren which have been known to fail
Where is the siren located? It is said to be disabled by last owner, I cannot see it in the engine compartment.

Thanks
dieselfan
 

audifan

A2OC Donor
So initially does the led flash rapidly for a few seconds then settle down to flashing every 3 seconds or so. Or does the led stay on constant before it starts to flash? Do you have mini DIS or full DIS? Do all the doors and hatch correctly show open and closed on the DIS? If this all Ok then faulty hazard/indicator relay.
 

dieselfan

A2OC Donor
So initially does the led flash rapidly for a few seconds then settle down to flashing every 3 seconds or so. Or does the led stay on constant before it starts to flash? Do you have mini DIS or full DIS? Do all the doors and hatch correctly show open and closed on the DIS? If this all Ok then faulty hazard/indicator relay.
Actually, none of the alternatives; I turn the key and 2.5s later I see the first led flash, then every 2.5s .
I have the mini DIS.
All four side doors shows ok as the drivers door on the DIS when opening them.
Boot hatch shows as boot.

Then, if I have understood this right... it's just to buy a new relay?

Many thanks for the super help 👍
dieselfan
 

audifan

A2OC Donor
The alarm appears to be picking up the doors properly closed, so do not think that is triggering the alarm. replacing the hazard / indicator relay is the next sensible step.
 

audifan

A2OC Donor
I have seen on some mini DIS the service hatch also shows, not sure if it does this on your car. The alarm will not set if the service hatch is open ( its microswitch ). If you open the service hatch then lock the car the alarm will not flash the door led. Now close the hatch, the indicators should flash and the door led start to flash. I take it you do not have remote locking?
 

dieselfan

A2OC Donor
The service hatch microswitch will be tested against the mini DIS as soon as I get access to her car.

Yes, that car (LHD BHC) has remote locking but as described in post #1, it's not working due to ECU and dashboard/instrument is temporary changed from (AMF) and keys are not paired.

A new indicator/hazard relay was ordered today.

Is it not unusual that both relays and both hazard switches as pairs, not shows any sign of error related to indicators, just starts the hazard flashing without notice ??

cheers
dieselfan
 

dieselfan

A2OC Donor
One of life's little mysteries I suppose. So why have you changed the ECU and instruments?
MoT was a week away and fuel gauge stopped working so I swapped instrument with a donor to be able to pass MoT...
Had to change ECU to get keys to work.
Not ideal, more like an act of panic...

Cheers
dieselfan
 

dieselfan

A2OC Donor
I have seen on some mini DIS the service hatch also shows, not sure if it does this on your car. The alarm will not set if the service hatch is open ( its microswitch ). If you open the service hatch then lock the car the alarm will not flash the door led. Now close the hatch, the indicators should flash and the door led start to flash. I take it you do not have remote locking?
Hi audifan,
The service hatch was tested today.
Service hatch do not appear in the mini DIS.
Alarm led starts to flash when I lock the door with the service hatch open.
Indicators do not start to flash when I close the service hatch... so it looks to me like there is no microswitch or that it is not connected?

I have rechecked the battery with multimeter and I have cracked an six sylinder 3.6 litre marine diesel with this battery and I have tried the check procedure with another battery too. I get the same result...

@audifan - as per your recommendations; I also checked battery terminal connections and did a handmilling to refresh surface of male and female cones.
The auxiliary positive connections and the fuse was checked too. No sign og oxide buildup or loose connections.
I have never noticed any sign of electrical issue with this A2, before this hazard flash issue....

Cheers
dieselfan
 

audifan

A2OC Donor
Double check the microswitch for the service hatch for either amissing rubber cover, switch not correctly secured, mechanism jammed or wiring issue. On my car the alarm will not arm if the hatch is open and the leds consequently do not flash. As soon as the hatch is locked the hazards flash once and the door led starts to flash. Not all cars show service hatch open on mini Dis but I have come across a few that do. It is important that the flap microswitch operates as this detects someone opening the flap to potentially steal the bonnet.
 

Olerype

Member
Why lock the car? The car has no value and is of no interest of anyone. Mine A2s are always open, outside my house, in the city, parkinghouse etc and have never been a problem the last 2 years practicing that. Except the key fob lose its memory hehe...
 
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