Peugeot 405 hazard warning flashing at random

Austria Wild

Austria Wild

Member
Fellow Frogger
Joined
Jan 11, 2019
Messages
102
Location
A Parallel Universe near England
G'day folks,

My 1993 405 GRI 2.0 automatic saloon lately does two flashes with its hazard warning lights seemingly at random. It does it when parked and locked, when parked and not locked and while driving. Initially it did it rather infrequently, but meanwhile it does it annoyingly often.

I would guess it has something to do with the factory installed alarm, since the ticking sound from the dashboard when it does this is distinctly different from the one it makes when you set the indicators, or switch on the hazard warning flashers, leading me to believe it's a separate relay. The normal indicator/hazard flasher relay sound of the 405 is almost inaudible (which I hate, I bet you always wanted to know that bit of trivia) and the one it makes when doing its random thing sounds much more like the relay ticking in any other car.

To my knowledge, there is no aftermarket alarm installed and never was. It has the stickers that it's Peugeot alarm equipped still in the windows. It does not seem to have an immobiliser and it does not have the keypad in the centre console as my other 405 has. We do use the key fob to lock/unlock it and that works fine, i.e. when locking or unlocking, it does it's 3 triple blinkerage as it is supposed to do.

So I'm reaching out to you lot in the hope someone knows that the bloody hell is going on.
Be much bethanked for any useful tips, virtual beer vouchers available etc.
 
Does the triple blink when you lock the car while inside have the same relay sound as the fault?

Also, are the two 'at random' flashes regular like the hazards are switched on? Tick pause Tick. Or are they irregular, as if a wire is shorting? I know you almost certainly mean the former, but a regular two flash sequence almost seems like it's a function of the alarm hence the question.
 
I would suspect the controller module (does it have such a thing?) has a problem. Possibly a capacitor on the blink (sic). A small discharge or a leak (that is a DC leak, not some goo or stuff like that) could be enough to trigger a blink or two.

That said, I would first swap in a good known relay anyway just to check the simple things first.
 
Check the stop light fuse. When this blows really strange things happen.
 
The triple blink when I lock the car while inside has not the same relay sound as the fault. In fact, it's completely silent.
Also, the two 'at random' flashes are regular like the hazards are switched on, tick pause tick, although they could be a bit faster paced, unless that perception is caused by my psyche. They are, however, not irregular, as if a wire is shorting.

I don't know whether it has a controller module, but if yes and this being faulty would mean the car's future is oval.
I have no idea where the relays are located and the OM doesn't mention the word once.

The stop light fuse is fine. The N/S stop light bulb has been changed recently, but IIRC the fault was there before.

However, upon checking whether the bulb is properly seated, I found this:




That red wire doesn't look original Peugeot to me. There is an equivalent one on the other side as well.
 
The extra red wire is most likely an earth wire , a common fix for 405 tail light wiring . I would agree with Graham and check all fuses . In my 405 if the fuse for the cigarette lighter blew I would have no indicators and the alternator light on the dash would come on , really strange wiring in these cars . Keith
 
keithm said:
The extra red wire is most likely an earth wire , a common fix for 405 tail light wiring . I would agree with Graham and check all fuses . In my 405 if the fuse for the cigarette lighter blew I would have no indicators and the alternator light on the dash would come on , really strange wiring in these cars . Keith
Click to expand...

Alternator light coming on is one of the things that happen when the stop light fuse blows. Alternator still charges fine with the light on though.
 
All fuses appear to be fine.

Another observation:

When it's doing its random thing, the green arrows on the dashboard flash as well, but not the red control light on the hazard warning switch.
 
Let's dismiss the alarm as a red herring for a moment.
Why would there be distinctively different relay sounds for when it's indicating at will, and when it's flashing randomly?
This could only mean there are two different relays, no?

Does anyone know where the indicator relay is located?
 
I had a 406 that did flash its lights etc at random intervals.

It was the end of the lights/indicator control arm that was worn causing intermittent connecting of various circuits that flashed lights, indicator arrows etc.

When it did this, I used to give the end of the arm a tug like I was trying to make it longer.
Flashing etc. stopped!

Cheers

Roland
 
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